研究者詳細 - 今村　維克

論文 - 今村　維克

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Pre-folding purification procedures for inclusion body-derived non-tagged cationic recombinant proteins with multiple disulfide bonds for efficient refolding. 国際誌

Shuichiro Kimura, Wataru Yamamoto, Ai Miyamoto, Koreyoshi Imamura, Junichiro Futami

Biotechnology progress e3532 2025年1月

記述言語：英語掲載種別：研究論文（学術雑誌）

The production of disulfide-containing recombinant proteins often requires refolding of inclusion bodies before purification. A pre-refolding purification step is crucial for effective refolding because impurities in the inclusion bodies interfere with refolding and subsequent purification. This study presents a new pre-refolding procedure using a reversible S-cationization technique for protein solubilization and purification by reversed-phase high performance liquid chromatography. This pre-folding purification step improves refolding yield by effectively removing the refolding inhibitors from contaminates from bacterial inclusion bodies, and reducing proteolytically degraded products. Because this procedure does not require a peptide tag for affinity purification, it is a superior technique to subsequently perform a simplified downstream process wherein the affinity tag needs to be removed. This study reports improved refolding and purification procedure to obtain the highly cationic (pI = 9.25) mouse vascular endothelial cell growth factor (188 amino acids form) that is used as a model protein in our study; this protein shows a homodimeric conformation and possesses multiple disulfides.

DOI： 10.1002/btpr.3532

噴霧乾燥および保存時におけるアモルファス固体分散中の疎水性薬剤の結晶化阻害に関する研究査読

Yamamoto, Rina, Imanaka, H, Ishida, Naoyuki, Imamura, Koreyoshi

Drying Technology 42 ( 13 ) 2022 - 2031 2024年11月

種々の条件における真空foam乾燥および噴霧乾燥によって調製したアモルファス固体分散体の香料保持特性査読

Nitta, Yuna, Sato, H, Yamamoto, Rina, Imanaka, Hiroyuki, Ishida, Naoyuki, Imamura, K

42 ( 2 ) 227 - 237 2024年1月

Water sorption and glass-to-rubber transition of amorphous sugar matrices, vacuum foam- and spray-dried from alcohols 査読

Koji Takeda, Shinta Miyazaki, Takashi Okamoto, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

JOURNAL OF FOOD ENGINEERING 349 2023年7月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCI LTD

The objective of this study is to understand the impact of preparation conditions on the physicochemical characteristics of amorphous sugar. Amorphous sugar (alpha-maltose, isomaltulose, trehalose) matrices were pre -pared from alcohol (methanol, ethanol) solutions, and their water sorption behavior and glass transition tem-peratures, Tg, were compared with those of aqueous freeze-dried amorphous sugar. Vacuum-foam-and spray -drying procedures were employed as drying methods. Water sorption for amorphous sugars, dried by different methods, was generally significant in the following order: vacuum-foam-drying < spray-drying <= freeze-drying. In the same order, the Tg values for the thoroughly dried amorphous sugars increased, and water sorption reduced the differences in Tg for given amounts of sorbed water. The solvent type in vacuum-foam-drying slightly affected the water sorption and the dependence of Tg on the sorbed water amount. The obtained findings sug-gested that physicochemical characteristics of amorphous sugar may relate to the sugar molecule conformations in solvent and dried state.

添付ファイル： JFOODENG-D-22-02113_R3-3.pdf

DOI： 10.1016/j.jfoodeng.2023.111483

Evaluation of interaction forces between hydrophobic surfaces in surfactant solutions by atomic force microscopy 査読

Shota Kage, Koreyoshi Imamura, Naoyuki Ishida

Colloid and Polymer Science 301 ( 7 ) 775 - 782 2023年7月

掲載種別：研究論文（学術雑誌）

The interaction forces between silica surfaces with various degrees of hydrophobicity were measured using colloidal probe atomic force microscopy to clarify the relationship between the hydrophobicity of the surfaces and hydrophobic attraction in detail. The interaction forces between silica surfaces pre-hydrophobised with octadecyltrichlorosilane were measured in aqueous solutions with three different (cationic, anionic, and nonionic) surfactants. Hydrophobic attraction was observed between surfaces from 10 to 15 nm without surfactant, and the range of this attraction decreased when the surface hydrophobicity decreased with increasing surfactant concentration. The hydrophobic attraction disappeared when the surface contact angle was below 80°–90° in the presence of all surfactants used in this study. The range of the hydrophobic attraction was found to depend strongly on the contact angle and not on the surfactant type and concentration. The adhesion force was also highly dependent on the contact angle and comparable to the theoretical capillary force. The possible origin of this force is discussed with reference to the obtained results. Graphical Abstract: [Figure not available: see fulltext.].

DOI： 10.1007/s00396-023-05118-w

Evaluation of Hydrophobic Attraction between Polystyrene Layer and Silanated Silica Surface by Atomic Force Microscopy 査読

Yuta Okuda, Koreyoshi Imamura, Naoyuki Ishida

Chemistry Letters 52 ( 12 ) 878 - 882 2023年

掲載種別：研究論文（学術雑誌）

In this study, hydrophobic surfaces were prepared by depositing polystyrene (PS) on a glass substrate using three different methods to measure the interaction forces against a hydrophobized particle by atomic force microscopy. We found that smooth surfaces prepared by spin coating and living radical polymerization generated hydrophobic attraction, whereas uneven surfaces obtained by free radical polymerization produced only steric repulsion, even though they had sufficient hydrophobicity. Based on these results, the origin of the hydrophobic attraction was suggested.

DOI： 10.1246/cl.230363

Kinetics of Enzymatic Reactions at the Solid/Liquid Interface in Nanofluidic Channels 査読

Koki Yamamoto, Kyojiro Morikawa, Hiroyuki Imanaka, Koreyoshi Imamura, Takehiko Kitamori

Analytical Chemistry 2022年10月

Extraordinary high preservation of the dispersion state of Au nanoparticles during freeze-thawing and freeze-drying with gum arabic 査読

Miki Kadowaki, Tsutashi Matsuura, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

Colloids and Surfaces A: Physicochemical and Engineering Aspects 639 2022年4月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

A series of edible and non-toxic substances were screened for their ability to prevent Au nanoparticles (AuNPs) from undergoing aggregation during both freeze-thawing and freeze-drying at as low an additive concentration as possible. Gum arabic was found to be an ideal choice. The addition of 20 µg/mL of gum arabic greatly inhibited the aggregation of AuNPs during freeze-thawing and -drying, whereas polyvinylpyrrolidone was the next best among the tested substances, with approximately 20% aggregation during freeze-drying at a concentration of less than 200 µg/mL. The zeta potential value of the AuNPs indicated the absence of the specific binding of gum arabic to the AuNPs surface. Surface enhanced infrared spectroscopic (SEIRAS) analyses were conducted for the gum arabic solution, frozen and freeze-dried on the Au particles. The results indicated that, in the frozen state, gum arabic molecules were concentrated in remaining unfrozen liquid on the Au coating without any specific orientation toward the Au surface. In contrast, SEIRAS spectra of freeze-dried gum arabic indicated that carboxylic groups in gum arabic molecules preferentially became closer to the Au surface. Considering these findings, during freeze-thawing, we conclude that the high thickening property of gum arabic gum plays an important role in minimizing the mobility and thus the aggregation of AuNPs in the freeze-concentrated regions between frozen ice crystals. The freeze-drying of a gum arabic solution produces a rigid amorphous matrix that has an affinity for the Au surface. The AuNPs were individually separated and immobilized in the freeze-dried matrix of the gum arabic, resulting in the extraordinary inhibition of their aggregation.

添付ファイル： COLSUA_128392_edit_report.pdf

DOI： 10.1016/j.colsurfa.2022.128392

Comparison of improvements of aqueous dissolution of structurally analogous hydrophobic drugs by amorphous solid dispersion 招待査読

Takashi Okamoto, Kayoko Yamamoto, Takanari Sekitoh, Akiho Fujioka, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

Colloids and Surfaces A: Physicochemical and Engineering Aspects 632 127744 - 127744 2022年1月

Induction of foaming in vacuum drying by needle stimulation and the impact of solution viscosity, vapor pressure, and the type of solute and solvent 査読

Akiho Fujioka, Rina Yamamoto, Olivier Tramis, Hiroaki Ishida, Tsutomu Ono, Naoyuki Ishida, Koreyoshi Imamura

Drying Technology 1 - 13 2021年12月

Foaming characteristics of sugar- and polyvinylpyrrolidone-alcohol solutions during vacuum foam drying: A rheological approach 査読

Olivier Tramis, Akiho Fujioka, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

Colloids and Surfaces A: Physicochemical and Engineering Aspects 627 127174 - 127174 2021年10月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Elsevier BV

Vacuum foam drying offers great perspectives to formulate solid-state encapsulated active drugs. Taking into account the specific need of pharmaceutical formulations to keep drug molecules active and dispersed, we show in this paper that vacuum drying of pharmaceutical formulations can be substantially improved by using original rheological approaches. Typically, our formulations totally dried-up in less than 5 min, a delay much shorter than the long hours of the traditional vacuum drying process. Steady-shear rheology was used to evaluate the solution's specific viscosity against the solutions' concentrations, in order to correlate the dilution regime to the foamabiltiy. This rheological approach indicated that in miscible solutions, spontaneous foaming occurred in the semi-dilute entangled regime, near the transition to the concentrated regime; for partially miscible solutions, it occurred in solutions at a concentration near to the percolation concentration. The proposed methodology is versatile, and should provide a simple way to assess the foamability of pharmaceutical formulations.

添付ファイル： P0NeedleTramis2-pub.pdf

DOI： 10.1016/j.colsurfa.2021.127174

Inhibiting Au nanoparticle aggregation in freeze-thawing by presence of various additives 査読

Miki Kadowaki, Hidetaka Yokota, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

Advanced Powder Technology 32 ( 10 ) 3517 - 3524 2021年10月

Direct measurements of interaction forces of bovine serum albumin and lysozyme with stainless steel by atomic force microscopy 査読

Hikaru Kawaguchi, Hiroyuki Imanaka, Koreyoshi Imamura, Naoyuki Ishida

Colloids and Surfaces A: Physicochemical and Engineering Aspects 627 127137 - 127137 2021年10月

Sole-amorphous-sugar-based solid dispersion of curcumin and the influence of formulation composition and heat treatment on the dissolution of curcumin 査読

Takanari Sekitoh, Takashi Okamoto, Akiho Fujioka, Olivier Tramis, Koji Takeda, Tsutashi Matsuura, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

Drying Technology 39 ( 14 ) 2065 - 2074 2021年9月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Informa UK Limited

An amorphous solid dispersion technique, in which hydrophobic drug molecules are dispersed in an amorphous matrix comprised solely of a sugar, was applied to curcumin that has excellent physiological functions. The sole-amorphous-sugar-based solid dispersion (SAS-SD) of curcumin was prepared by vacuum foam drying from methanol, using various disaccharides as the drug carrier-forming component. Aqueous dissolution of curcumin from the SAS-SD showed “spring-and-parachute” shape profile and was markedly increased when a sugar (α-maltose or trehalose) was added in a composition range ≥100 g-sugar/g-curcumin. Further dissolution was achieved by heating the SAS-SD at close to and above the melting points of curcumin.

添付ファイル： P0SF-Cur-draft.pdf

DOI： 10.1080/07373937.2020.1752711

アルコールから乾燥調製したトレハロースアモルファスの結晶化特性査読

関藤孝成, 岡本崇, 藤岡亜希穂, 吉岡朋彦, 照井真司, 今中洋行, 石田尚之, 今村維克

292 110325 - 110325 2021年3月

Direct measurement of interaction force between hydrophilic silica surfaces in triblock copolymer solutions with salt by atomic force microscopy 査読

Takumi Deguchi, Takato Nakahara, Koreyoshi Imamura, Naoyuki Ishida

Advanced Powder Technology 32 ( 1 ) 30 - 36 2021年1月

ポリビニルピロリドンおよび糖のアルコール溶液の真空乾燥における自発的な発泡と難水溶性薬物の対水溶解性の改善査読

Olivier Tramis,藤岡亜希穂,今中洋行,石田尚之,今村維克

1 - 11 2020年9月

食品タンパク質をはじめとする生体分子の包括安定化技術に関する工学研究招待査読

今村維克

日本食品工学会誌 21 ( 3 ) 95 - 111 2020年9月

A suitable and effective stepwise oxidative refolding procedure for highly‐cationic tetrameric avidin in nucleic acid free conditions 査読国際誌

Shuichiro Kimura, Koreyoshi Imamura, Junichiro Futami

Biotechnology Progress 36 ( 5 ) e3031 2020年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Wiley

Optimized conditions are needed to refold recombinant proteins from bacterial inclusion bodies into their biologically active conformations. In this study, we found two crucial requirements for efficient refolding of cationic tetrameric chicken avidin. The first step is to eliminate nucleic acid contaminants from the bacterial inclusion body. The electrostatic interactions between the remaining nucleic acids and proteins strongly enhanced protein aggregation during the refolding process. The cysteine specific reversible S-cationization procedure was successfully employed for large-scale preparation of nucleic acid free denatured protein without purification tag system. The second step is the intramolecular disulfide formation prior to refolding in dialysis removing denaturant. Disulfide intact monomeric avidin showed efficient formation of biologically active tetrameric conformation during the refolding process. Using this optimized refolding procedure, highly cationic avidin derivative designed as an intracellular delivery carrier of biotinylated protein was successfully prepared.

DOI： 10.1002/btpr.3031

その他リンク： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/btpr.3031

糖および界面活性剤複合系による金ナノ粒子の凍結乾燥における分散安定化査読

横田秀隆, 門脇美季, 松浦傳史, 今中洋行, 石田尚之, 今村維克

36 ( 24 ) 6698 - 6705 2020年6月

外部電場による表面非親和性タンパク質の金属表面への固定化査読

129 ( 3 ) 348 - 353 2020年3月

バルクでの反応速度を超えるナノ流体デバイス上のピコリットル酵素反応装置査読

The Analyst 145 ( 17 ) 5801 - 5807 2020年

Pico-liter protein digestion and separation using nanofluidic device

Kyojiro Morikawa, Koki Yamamoto, Hiroki Sano, Yutaka Kaoze, Hisashi Shimizu, Hiroyuki Imanaka, Koreyoshi Imamura, Takehiko Kitamori

MicroTAS 2020 - 24th International Conference on Miniaturized Systems for Chemistry and Life Sciences 1125 - 1126 2020年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：Chemical and Biological Microsystems Society

The Needs of shotgun proteomics have been increasing in the field of biology and medicine for understanding biological systems. In study, protein sample with pL, which volume was same scale as single cell volume, was successfully digested and separated and detected by integrated device of pL enzyme reactor fL chromatography and UV-POPS detector. This nanofluidic device will greatly contribute to single cell shotgun proteomics.

ニードル刺激によるfoaming誘導を利用した低真空下における真空foam乾燥の乾燥履歴の制御査読

日高史博, 佐藤朋, 藤岡亜希穂, 竹田昂司, 今中洋行, 石田尚之, 今村維克

37 ( 12 ) 1520 - 1527 2019年9月

アモルファス固体分散体としてメタノールから乾燥した糖類アモルファスマトリクスの物理的安定性と熱処理の影響査読

竹田昂司, 関藤孝成, 藤岡亜希穂, 山本佳代子, 岡本崇, 松浦傳史, 今中洋行, 石田尚之, 今村維克

Journal of Pharmaceutical Sciences 108 ( 6 ) 2056 - 2062 2019年6月

Nanofluidic enzyme reactor exceeding limit of bulk reaction rate

Koki Yamamoto, Kyojiro Morikawa, Koreyoshi Imamura, Hiroyuki Imanaka, Takehiko Kitamori

23rd International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2019 113 - 114 2019年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：Chemical and Biological Microsystems Society

We development a nanofluidic enzyme reactor exceeding the limitation of bulk enzyme reaction. The limit concentration of bulk trypsin solution is approximately 0.5 PM because self-digestion occurs over 0.5 PM solution, which complicates analysis of target proteins by digestion trypsin itself. Using extremely high surface/volume ration of nanospace, trypsin concentration, which indicates number of immobilized trypsin molecules on the nanochannel surface for liquid phase volume, exceed to bulk limit of concentration. As a result, 31 times higher concentration and 33 times faster enzyme reaction compared to bulk was realized. This reactor will be powerful tools which overcomes limitation in bulk and microfluidic method.

Adsorption characteristics of various proteins on a metal surface in the presence of an external electric potential 査読

Colloids and Surfaces B: Biointerfaces 166 262 - 268 2018年6月

Hydrophobic Attraction Measured between Asymmetric Hydrophobic Surfaces 査読

Naoyuki Ishida, Kohei Matsuo, Koreyoshi Imamura, Vincent S. J. Craig

Langmuir 34 ( 12 ) 3588 - 3596 2018年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：American Chemical Society

The interaction forces between silica surfaces modified to different degrees of hydrophobicity were measured using colloidal probe atomic force microscopy (AFM). A highly hydrophobic silica particle was prepared with octadecyltrichlorosilane (OTS), and the interaction forces were measured against silica substrates modified to produce surfaces of varying hydrophobicity. The interaction forces between the highly hydrophobic particle and a completely hydrophilic silicon wafer surface fitted well to the DLVO theory, indicating that no additional (non-DLVO) forces act between the surfaces. When the silicon wafer surface was treated to produce a contact angle of water on surface of 40°, an additional attractive force that is longer ranged than the van der Waals force was observed between the surfaces. The range and magnitude of the attractive force increase with the contact angle of water on the substrate. Beyond the effect on the contact angle, the hydrocarbon chain length and the terminal groups of hydrophobic layer on the substrate only have a minor effect on the magnitude of the force, even when the substrate is terminated with polar carboxyl groups, provided the hydrophobicity of the other surface is high.

DOI： 10.1021/acs.langmuir.7b04246

Influence of an external electric field on removal of protein fouling on a stainless steel surface by proteolytic enzymes 査読

COLLOIDS AND SURFACES B-BIOINTERFACES 159 118 - 124 2017年11月

Characteristics of proteinaceous additives in stabilizing enzymes during freeze-thawing and -drying 査読

Takanori Shimizu, Tamayo Korehisa, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY 81 ( 4 ) 687 - 697 2017年4月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：TAYLOR & FRANCIS LTD

Protein-stabilizing characteristics of sixteen proteins during freeze-thawing and freeze-drying were investigated. Five enzymes, each with different instabilities against freezing and dehydration, were employed as the protein to be stabilized. Proteinaceous additives generally resulted in greater enzyme stabilization during freeze-thawing than sugars while the degree of stabilization for basic lysozyme and protamine were inferior to that of neutral and acidic proteins. Freeze-drying-induced inactivation of enzyme was also reduced by the presence of a proteinaceous additive, the extent of which was lower than that for a sugar. In both freeze thawing and freeze drying, the enzymes stabilization by the proteinaceous additive increased with increasing additive concentration. The enhancement of enzyme inactivation caused by pH change was also reduced in the presence of proteinaceous additives. The combined use of a sugar such as sucrose and dextran tended to increase the stabilizing effect of the proteinaceous additive.

添付ファイル： TBBB_A_1274637r1.pdf

DOI： 10.1080/09168451.2016.1274637

Surfactant-Free Solid Dispersions of Hydrophobic Drugs in an Amorphous Sugar Matrix Dried from an Organic Solvent 査読

Koji Takeda, Yuto Gotoda, Daichi Hirota, Fumihiro Hidaka, Tomo Sato, Tsutashi Matsuura, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

MOLECULAR PHARMACEUTICS 14 ( 3 ) 791 - 798 2017年3月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

The technique for homogeneously dispersing hydrophobic drugs in a water-soluble solid matrix (solid dispersion) is a subject that has been extensively investigated in the pharmaceutical industry. Herein, a novel technique for dispersing a solid, without the need to use a surfactant, is reported. A freeze-dried amorphous sugar sample was dissolved in an organic solvent, which contained a soluble model hydrophobic component. The suspension of the sugar and the model hydrophobic component was vacuum foam dried to give a solid powder. Four types of sugars and methanol were used as representative sugars and the organic medium. Four model drugs (indomethacin, ibuprofen, gliclazide, and nifedipine) were employed. Differential scanning calorimetry analyses indicated that the sugar and model drug (100:1) did not undergo segregation during the drying process. The dissolution of the hydrophobic drugs in water from the solid dispersion was then evaluated, and the results indicated that the C-max and AUC(0-60) (min) of the hydrophobic drug in water were increased when the surfactant-free solid dispersion was used. Palatinose and/or alpha-maltose were superior to the other tested carbohydrates in increasing C-max and AUC(0-60 min), for all tested model drugs, and the model drug with a lower water solubility tended to exhibit a greater extent of over-dissolution.

添付ファイル： P0SF-DrugProof.pdf

DOI： 10.1021/acs.molpharmaceut.6b01048

Adsorption of lysozyme on base metal surfaces in the presence of an external electric potential 査読

Ei Ei Htwe, Yuhi Nakama, Hiroshi Tanaka, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

COLLOIDS AND SURFACES B-BIOINTERFACES 147 9 - 16 2016年11月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

The impact of external electric potential on the adsorption of a protein to base metal surfaces was examined. Hen egg white lysozyme (LSZ) and six types of base metal plates (stainless steel SUS316L (St), Ti, Ta, Zr, Cr, or Ni) were used as the protein and adsorption surface, respectively. LSZ was allowed to adsorb on the surface under different conditions (surface potential, pH, electrolyte type and concentration, surface material), which was monitored using an ellipsometer. LSZ adsorption was minimized in the potential range above a certain threshold and, in the surface potential range below the threshold, decreasing the surface potential increased the amount of protein adsorbed. The threshold potential for LSZ adsorption was shifted toward a positive value with increasing pH and was lower for Ta and Zr than for the others. A divalent anion salt (K2SO4) as an electrolyte exhibited the adsorption of LSZ in the positive potential range while a monovalent salt (KCI) did not. A comprehensive consideration of the obtained results suggests that two modes of interactions, namely the electric force by an external electric field and electrostatic interactions with ionized surface hydroxyl groups, act on the LSZ molecules and determine the extent of suppression of LSZ adsorption, All these findings appear to support the view that a base metal surface can be controlled for the affinity to a protein by manipulating the surface electric potential as has been reported on some electrode materials. (C) 2016 Elsevier B.V. All rights reserved.

添付ファイル： P2LSZ-pub.pdf

DOI： 10.1016/j.colsurfb.2016.07.042

Molecular design of proteinaceous cushion for sensitive biomolecular interaction detection system

Hiroyuki Imanaka, Koki Dare, Koreyoshi Imamura

NEW BIOTECHNOLOGY 33 S72 - S72 2016年7月

Surfactant-free solid dispersion of fat-soluble flavour in an amorphous sugar matrix 査読

Tomo Satoh, Fumihiro Hidaka, Kento Miyake, Natsuki Yoshiyama, Koji Takeda, Tsutashi Matsuura, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

FOOD CHEMISTRY 197 1136 - 1142 2016年4月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCI LTD

A solid dispersion technique to homogeneously disperse hydrophobic ingredients in a water-soluble solid without using surfactant was examined as follows: first, freeze-dried amorphous sugar was dissolved in an organic medium that contained a soluble model hydrophobic component. Second, the mixed solution of sugar and the model hydrophobic component was vacuum dried into a solid (solid dispersion). Methanol and six fat-soluble flavours, including cinnamaldehyde, were used as organic media and model hydrophobic components. The retention of flavours in the solid dispersion during drying and storage under vacuum was evaluated. The amorphised disaccharides dissolved in methanol up to 100 mg/mL, even temporarily (20 s to 10 days) and could be solidified without any evidence of crystallisation and segregation from flavour. The solid dispersion, prepared using a-maltose usually showed 65-95% flavour retention during drying (and storage for cinnamaldehyde), whereas >= 50% of the flavour was lost when the flavour was O/W emulsified with a surfactant and then freeze-dried with sugar. (C) 2015 Elsevier Ltd. All rights reserved.

添付ファイル： P0SurfFree-drft.pdf

DOI： 10.1016/j.foodchem.2015.11.097

The use of a proteinaceous "cushion" with a polystyrene-binding peptide tag to control the orientation and function of a target peptide adsorbed to a hydrophilic polystyrene surface 査読

Hiroyuki Imanaka, Daisuke Yamadzumi, Keisuke Yanagita, Naoyuki Ishida, Kazuhiro Nakanishi, Koreyoshi Imamura

BIOTECHNOLOGY PROGRESS 32 ( 2 ) 527 - 534 2016年3月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-BLACKWELL

In immobilizing target biomolecules on a solid surface, it is essential (i) to orient the target moiety in a preferred direction and (ii) to avoid unwanted interactions of the target moiety including with the solid surface. The preferred orientation of the target moiety can be achieved by genetic conjugation of an affinity peptide tag specific to the immobilization surface. Herein, we report on a strategy for reducing the extent of direct interaction between the target moiety and surface in the immobilization of hexahistidine peptide (6His) and green fluorescent protein (GFP) on a hydrophilic polystyrene (PS) surface: Ribonuclease HII from Thermococcus kodakaraensis (cHII) was genetically inserted as a cushion between the PS-affinity peptide tag and target moiety. The insertion of a cushion protein resulted in a considerably stronger immobilization of target biomolecules compared to conjugation with only a PS affinity peptide tag, resulting in a substantially enhanced accessibility of the detection antibody to the target 6His peptide. The fluorescent intensity of the GFP moiety was decreased by approximately 30% as the result of fusion with cHII and the PS-affinity peptide tag but was fully retained in the immobilization on the PS surface irrespective of the increased binding force. Furthermore, the fusion of cHII did not impair the stability of the target GFP moiety. Accordingly, the use of a proteinaceous cushion appears to be promising for the immobilization of functional biomolecules on a solid surface. (c) 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:527-534, 2016

添付ファイル： BTPR_2232corected.pdf

DOI： 10.1002/btpr.2232

クッションタンパク質の分子デザインによるバイオ分子間相互作用の高感度化

今中洋行, 伊達弘輝, 的場晴香, 石田尚之, 今村維克

表面科学学術講演会要旨集 36 37 - 37 2016年

記述言語：日本語出版者・発行元：公益社団法人日本表面科学会

ELISA，SPRやQCMなどのバイオ分子間相互作用検出系における基板上へのリガンド分子の固定化について，基板親和性ペプチド連結による固定化配向制御ならびにリガンド分子と基板との直接的な相互作用を緩和するクッションタンパク質を用いた機能維持を試みた．そして，クッションタンパク質の様々な分子デザインにより，ペプチド-タンパク質間あるいはタンパク質-タンパク質間相互作用検出を顕著に高感度化できた．

DOI： 10.14886/sssj2008.36.0_37

Effect of surface hydrophobicity on short-range hydrophobic attraction between silanated silica surfaces 査読

Yuhei Soga, Hiroyuki Imanaka, Koreyoshi Imamura, Naoyuki Ishida

ADVANCED POWDER TECHNOLOGY 26 ( 6 ) 1729 - 1733 2015年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

The interaction forces between silanated silica surfaces without nanobubbles were measured using colloidal probe atomic force microscopy (AFM). To obtain hydrophobic surfaces without nanobubbles, an aqueous solution was introduced between the surfaces following an exchange process involving several solvents. In the obtained approaching force curves, an attractive force was observed from a distance of 10-20 nm, which is an additional attractive force stronger than typical van der Waals attractions. When the surface hydrophobicity decreased, the range of this attraction decreased slightly; the attraction disappeared when the surface contact angle was below 90 degrees. In contrast, measurements in the water-ethanol mixtures revealed that the attraction persisted even when the contact angle was well below 90 degrees. The possible origin of this force was discussed on the basis of the obtained results. (C) 2015 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan.

DOI： 10.1016/j.apt.2015.10.017

Inhibitory effects of additives and heat treatment on the crystallization of freeze-dried sugar 査読

Kohshi Kinugawa, Mitsunori Kinuhata, Ryo Kagotani, Hiroyuki Imanaka, Naoyuki Ishida, Mizuki Kitamatsu, Kazuhiro Nakanishi, Koreyoshi Imamura

JOURNAL OF FOOD ENGINEERING 155 37 - 44 2015年6月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCI LTD

An amorphous matrix of a sugar is frequently used as a bulk-forming and stabilizing agent in the food industry but tends to crystallize as the result of water uptake and increase in temperature. Additives and methods used to inhibit the crystallization of amorphous sugar (sucrose) were screened in this study. Freeze-dried amorphous sucrose containing 0.5-5 wt% of additive, including salts, different types of sugars, and polymers, the crystallization temperature (T-cry) and isothermal crystallization characteristics were examined. Certain types of salts markedly increased the Tcry and prolonged the induction period for crystal nucleation. The use of 1 wt% MgCl2 was particularly effective in inhibiting sugar crystallization. The heat treatment of crystalline sucrose under appropriate conditions was also found to result in diminished sucrose crystallization. MALDI-TOF mass spectra of the heat-treated sucrose suggested that sucrose derivatives containing multiple pyranose groups were formed, which would closely relate to the crystallization inhibition. Finally, the protein stabilizing effects of the matrices were evaluated. The results indicated that both the addition of additives and the heat treatment resulted in an improvement of the protein stabilizing effect of amorphous sugar matrix, compared to that of sucrose alone. (C) 2015 Elsevier Ltd. All rights reserved.

添付ファイル： P0CryInh-proof.pdf

DOI： 10.1016/j.jfoodeng.2015.01.016

Influence of sugar surfactant structure on the encapsulation of oil droplets in an amorphous sugar matrix during freeze-drying 査読

Shota Nakayama, Yoshifumi Kimura, Sayuri Miki, Jun Oshitani, Takashi Kobayashi, Shuji Adachi, Tsutashi Matsuura, Hiroyuki Imanaka, Naoyuki Ishida, Hiroko Tada, Kazuhiro Nakanishi, Koreyoshi Imamura

FOOD RESEARCH INTERNATIONAL 70 143 - 149 2015年4月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

The encapsulation of O/W emulsion droplets in a freeze-dried amorphous sugar matrix was investigated, focusing on the impact of the molecular structure of the emulsifying surfactant. O/W emulsions, containing various surfactants, were freeze-dried in the presence of a sugar. Thirty types of surfactants, including eighteen different sugar surfactants and ten types of commercially available sugar ester mixtures, were used. Linoleic acid methyl ester and trehalose were used as the oil phase and sugar. The amounts of oil droplets encapsulated in freeze-dried amorphous sugar matrix were analyzed by Fourier transform Infrared spectroscopy. Sugar surfactants were generally superior to the other classes of surfactants for oil droplet encapsulation during freeze-drying, and there was the optimum alkyl chain length of the sugar surfactant. Sugar esters generally exhibited greater oil encapsulation than sugar ethers. Larger sugar head group appeared to result in better encapsulation in the case of sugar esters, but the opposite tendency was found for sugar ethers. A limited combination of sugar surfactants (15% sucrose mono- and 85% di-stearate) resulted in the maximum oil droplet encapsulation efficiency although these surfactants are individually quite poor in the encapsulation and other tested combinations did not improve the encapsulation efficiency relative to their individual effectiveness. (C) 2015 Elsevier Ltd. All rights reserved.

添付ファイル： P1AOex-pub.pdf

DOI： 10.1016/j.foodres.2015.02.003

Effect of Lipid Amount on Surfactant-free Solid Lipid Nanoparticle Formation by Hot Homogenization 査読

Jun Oshitani, Natsumi Murakami, Mikio Yoshida, Naoyuki Ishida, Koreyoshi Imamura, Hideki Ichikawa

CHEMISTRY LETTERS 43 ( 7 ) 1011 - 1013 2014年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CHEMICAL SOC JAPAN

The yield and size distribution of surfactant-free solid lipid nanoparticles (SF-SLNs) formed by hot homogenization were investigated by changing the amount of lipid (palmitic acid). The yield was 100% and monodispersed same-sized particles of 120-200 nm were formed at the lipid amount <= 2.8 x 10(-4) g-lipid (g-water)(-1). The yield decreased owing to phase separation, and the size increased "step-likely" to be 200 350 nm while keeping the monodispersity when the lipid amount was just above <= 2.8 x 10(-4) g-lipid (g-water)(-1). The size and the lipid amount continued to increase gradually at the lipid amount >2.8 x 10(-4) g-lipid (g-water)(-1). The results indicate that submicron-sized solid lipid particles can be formed without surfactants and that the decrease of yield and the step-like increase of particle size occur at the same lipid amount. The total surface area of the SF-SLNs was estimated using the experimental data. It is suggested that the total surface area and the lipid amount are correlated to each other.

DOI： 10.1246/cl.140279

Characteristics of Sugar Surfactants in Stabilizing Proteins During Freeze-Thawing and Freeze-Drying 査読

Koreyoshi Imamura, Katsuyuki Murai, Tamayo Korehisa, Noriyuki Shimizu, Ryo Yamahira, Tsutashi Matsuura, Hiroko Tada, Hiroyuki Imanaka, Naoyuki Ishida, Kazuhiro Nakanishi

JOURNAL OF PHARMACEUTICAL SCIENCES 103 ( 6 ) 1628 - 1637 2014年6月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-BLACKWELL

Sugar surfactants with different alkyl chain lengths and sugar head groups were compared for their protein-stabilizing effect during freeze-thawing and freeze-drying. Six enzymes, different in terms of tolerance against inactivation because of freeze-thawing and freeze-drying, were used as model proteins. The enzyme activities that remained after freeze-thawing and freeze-drying in the presence of a sugar surfactant were measured for different types and concentrations of sugar surfactants. Sugar surfactants stabilized all of the tested enzymes both during freeze-thawing and freeze-drying, and a one or two order higher amount of added sugar surfactant was required for achieving protein stabilization during freeze-drying than for the cryoprotection. The comprehensive comparison showed that the C10-C12 esters of sucrose or trehalose were the most effective through the freeze-drying process: the remaining enzyme activities after freeze-thawing and freeze-drying increased at the sugar ester concentrations of 1-10 and 10-100 M, respectively, and increased to a greater extent than for the other surfactants at higher concentrations. Results also indicate that, when a decent amount of sugar was also added, the protein-stabilizing effect of a small amount of sugar ester through the freeze-drying process could be enhanced. (c) 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci

添付ファイル： P1SugSF-pub.pdf

DOI： 10.1002/jps.23988

糖界面活性剤を用いたタンパク質の安定化

今村維克

オレオサイエンス 14 ( 11 ) 487 - 493 2014年

記述言語：日本語出版者・発行元：公益社団法人日本油化学会

<p>タンパク質は食品や医薬品分野で不可欠な材料であるが，非生理的環境下では容易に変性し，その優れた生理活性を失ってしまう場合が多い。そのためタンパク質の安定化技術，とりわけ安定化物質の探索が以前より行われてきた。一方，糖を親水基とする糖界面活性剤は食品添加物として広範に利用されているが，タンパク質の変性を抑制する作用も有している。本稿では，タンパク質が曝される各状態・操作における変性機構とともに，糖界面活性剤のタンパク質安定化における有効性について述べる。特に凍結および凍結乾燥過程におけるタンパク質安定化作用について，種々の糖界面活性剤が各種酵素の活性保持に対する影響を調査し，糖界面活性剤の極性基の構造やアルキル鎖長，およびアルキル鎖との結合形態が凍結および凍結乾燥時におけるタンパク質安定化作用に及ぼす影響について考察を加えた。</p>

DOI： 10.5650/oleoscience.14.487

その他リンク： http://search.jamas.or.jp/link/ui/2015030450

水中の疎水化シリカ表面間に働く短距離性疎水性引力に及ぼす表面の疎水性の影響

曽我友平, 今中洋行, 今村維克, 石田尚之

粉体工学会誌 51 ( 5 ) 343 - 348 2014年

記述言語：英語出版者・発行元：一般社団法人粉体工学会

The interaction forces between silanated silica surfaces with no nanobubbles were measured using colloidal probe atomic force microscopy (AFM). To obtain hydrophobic surfaces without nanobubbles, an aqueous solution was introduced between the surfaces following an exchange process involving several solvents. In the obtained approachingforce curves, an attractive force was observed from a distance of 10～20 nm, which is an additional attractive force stronger than typical van der Waals attractions. When the surface hydrophobicity decreased, the range of this attraction decreased slightly ; the attraction disappeared when the surface contact angle was below 90°。. In contrast, measurements in the water-ethanol mixtures revealed that the attraction persisted even when the contact angle was well below 90°。. The possible origin of this force was discussed on the basis of the obtained results.

DOI： 10.4164/sptj.51.343

2P078 新規金表面親和性ペプチドの同定及びタンパク質固定化への応用(01D. 蛋白質:機能,ポスター,第52回日本生物物理学会年会(2014年度))

Shigemori Yojiro, Yoshida Kaori, Imamura Koreyoshi, Takahashi Yuichiro, Imanaka Hiroyuki

生物物理 54 ( 1 ) S207 2014年

2P085 CS複合体形成をモデルとした高感度ペプチド-タンパク質間相互作用検出系のデザイン(01F. 蛋白質:蛋白質工学/進化工学,ポスター,第52回日本生物物理学会年会(2014年度))

Matsushita Runa, Ishida Naoyuki, Imamura Koreyoshi, Imanaka Hiroyuki

生物物理 54 ( 1 ) S209 2014年

Improving the physical stability of freeze-dried amorphous sugar matrices by compression at several hundreds MPa 査読

Ryo Kagotani, Kohshi Kinugawa, Mayo Nomura, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

JOURNAL OF PHARMACEUTICAL SCIENCES 102 ( 7 ) 2187 - 2197 2013年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-BLACKWELL

Amorphous matrices, composed of sugars, are markedly plasticized by moisture uptake, which results in physical instability. Our previous studies, in the compression pressure range 443 MPa, indicated that when a matrix is compressed, the amount of sorbed water at given relative humidities (RHs) decreases, whereas the glass transition temperature (Tg) remains constant. Herein, the effect of higher compression pressures than those used previously was explored to investigate the feasibility of using compression to improve the physical stability of amorphous sugar matrix against water uptake and subsequent collapse. Amorphous sugar samples were prepared by freeze-drying and then compressed at 0-665 MPa, followed by rehumidification at given RHs. The physical stability of the amorphous sugar sample was evaluated by measuring Tg and crystallization temperature (Tcry). The amounts of sorbed water, different in the interaction state, were determined using an FTIR technique. It was found that the compression at pressures of 443 MPa decreased the amount of sorbed water, which is a major factor in plasticization and crystallization, and thus markedly increased the Tg and Tcry relative to that for the uncompressed sample. Hence, the compression at several hundreds MPa appears to be feasible for improving the physical stability of amorphous sugar matrix. (c) 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:2187-2197, 2013

DOI： 10.1002/jps.23568

Improvement on the freeze-thaw stability of corn starch gel by the polysaccharide from leaves of Corchorus olitorius L. 査読

Eiji Yamazaki, Toru Sago, Yoshiaki Kasubuchi, Kazuhito Imamura, Toshio Matsuoka, Osamu Kurita, Hironobu Nambu, Yasuki Matsumura

Carbohydrate Polymers 94 ( 1 ) 555 - 560 2013年4月

記述言語：英語掲載種別：研究論文（学術雑誌）

Effect of the polysaccharide from leaves of Corchorus olitorius L. (PLC) on the freeze-thaw (FT) stability of corn starch gel was studied. PLC was incorporated into the starch gel at 0.7% and total solid was adjusted to 6.0%. The syneresis was measured by the centrifugal-filtration method and, as a result, addition of PLC reduced effectively the syneresis of the starch gel even after 5 FT cycles, which was less than one third that of the normal starch gel. The rheological changes of the starch/PLC gel during the FT treatments were evaluated while the gel remained on the rheometer plate. The starch/PLC gel had less significant changes in the rheological parameters during the FT cycles than starch/guar gum or xanthan gum gel systems. SEM images showed that PLC stabilized the gel matrix surrounding pores, which would contribute to both a lower syneresis production and a higher stability in the rheological behavior at FT. © 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.carbpol.2013.01.079

Characteristics of amorphous matrices composed of different types of sugars in encapsulating emulsion oil droplets during freeze-drying 査読

Koreyoshi Imamura, Yoshifumi Kimura, Shota Nakayama, Miki Sayuri, Seiji Ogawa, Tatsuya Hoshino, Jun Oshitani, Takashi Kobayashi, Shuji Adachi, Tsutashi Matsuura, Hiroyuki Imanaka, Naoyuki Ishida, Kazuhiro Nakanishi

FOOD RESEARCH INTERNATIONAL 51 ( 1 ) 201 - 207 2013年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

The encapsulation of emulsion oil droplets by amorphous sugar matrices, formed by freeze-drying, was investigated, with a focus on the influence of the type of sugar. An oil-in-water emulsion, comprised of linoleic acid methyl ester (LME) and sucrose monolaurate (SML) as an oil phase and surfactant, respectively, were freeze-dried in the presence of different types of sugars. LME-droplet encapsulation during and after freeze-drying were evaluated by FTIR analysis. The loss of LME largely occurred in the early stage of freeze-drying. The size distribution of the encapsulated LME droplets remained unchanged before and after freeze-drying in most cases. The encapsulated fractions of LME droplets could be correlated with the glass transition temperature of the sugars in the fully hydrated state (T-g*), and the existence of an optimum T-g* value for the sugar matrix was predicted. The encapsulation ability of an amorphous sugar matrix was maximized when mono- and polysaccharide were combined so as to give a value for T-g* of approximately -50 degrees C, although, individually, mono- and polysaccharides were quite poor for oil droplet encapsulation. These findings suggest that the structural flexibility of the amorphous sugar matrix is a major determinant in oil droplet encapsulation by an amorphous sugar matrix during freeze-drying. (C) 2012 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.foodres.2012.12.010

On the preparation of indoxyl red from indican and some new characteristics 査読

Jingyuan Song, Mizuki Kitamatsu, Koreyoshi Imamura, Hitoshi Ohmori, Kouji Watanabe, Kazuhiro Nakanishi

BIOORGANIC & MEDICINAL CHEMISTRY LETTERS 23 ( 3 ) 627 - 629 2013年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD

An indole compound with a strong purple-red color was produced by boiling a solution of indican under acidic conditions and purified by chromatographies on DEAE-650S Toyopearl TSK-gel and silica-gel columns. The purple-red compound purified was identified as indoxyl red, on the basis of FAB Mass, C-13 NMR, H-1 NMR, UV-visible spectra, and IR spectra. Although indoxyl red was first synthesized by Seidel(9) 70 years ago, very little information has been available on its characteristics. We repot here that the compound was purple-red colored at acidic pH and green at pH 13, and showed antiproliferative and cytotoxic activities to the mouse B cell lymphoma cell line NSF202. (c) 2012 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.bmcl.2012.12.006

The discoidin domain of Bacillus circulans β-galactosidase plays an essential role in repressing galactooligosaccharide production. 査読

Song J, Imanaka H, Imamura K, Minoda M, Yamaguchi S, Nakanishi K

Bioscience, biotechnology, and biochemistry 77 ( 1 ) 73 - 79 2013年1月

Impact of compression, physical aging, and freezing rate on the crystallization characteristics of an amorphous sugar matrix 査読

Koreyoshi Imamura, Kohshi Kinugawa, Ryo Kagotani, Mayo Nomura, Kazuhiro Nakanishi

JOURNAL OF FOOD ENGINEERING 112 ( 4 ) 313 - 318 2012年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCI LTD

Amorphous matrices made up of sugar molecules, are frequently used in food and pharmaceutical industries. A drawback to their use is that they are susceptible to collapse, as a result of water uptake and an increase in temperature and subsequently crystallize. Herein, the crystallization characteristics of amorphous sugar (sucrose and alpha-lactose) preparations were analyzed, with the purpose of obtaining knowledge that could lead to the prediction of how long the amorphous state is retained under various conditions. The impact of compression, physical aging and freezing rate on the induction period (t(ind)) for crystallization were examined. Freeze-dried sugar samples were compressed at 74 or 443 MPa (5 min) and then rehumidified at specified RHs. Some freeze-dried sucrose samples were physically aged, and alternatively freeze-drying was conducted under different conditions. The isothermal crystallization of the prepared samples at different temperatures (T), the glass transition and the crystallization temperature (T-cry) were measured, using differential scanning calorimetry. The compression markedly decreased the t(ind), while significantly lowered the hygroscopicity. Physical aging and slower-freezing also shortened the t(ind). The t(ind) was found to be correlated exclusively with (T-cry-T), regardless of rehumidification, compression, sugar type, physical aging and freezing rate in the freeze-drying process. (C) 2012 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.jfoodeng.2012.05.004

Heterogeneity of the state and functionality of water molecules sorbed in an amorphous sugar matrix 査読

Koreyoshi Imamura, Ryo Kagotani, Mayo Nomura, Kohshi Kinugawa, Kazuhiro Nakanishi

CARBOHYDRATE RESEARCH 351 108 - 113 2012年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCI LTD

An amorphous matrix, comprised of sugar molecules, is frequently used in the pharmaceutical industry. An amorphous sugar matrix exhibits high hygroscopicity, and it has been established that the sorbed water lowers the glass transition temperature T-g of the amorphous sugar matrix. It is naturally expected that the random allocation and configuration of sugar molecules would result in heterogeneity of states for sorbed water. However, most analyses of the behavior of water, when sorbed to an amorphous sugar matrix, have implicitly assumed that all of the sorbed water molecules are in a single state. In this study, the states of water molecules sorbed in an amorphous sugar matrix were analyzed by Fourier-transform IR spectroscopy and a Fourier self-deconvolution technique. When sorbed water molecules were classified into five states, according to the extent to which they are restricted, three of the states resulted in a lowering of T-g of an amorphous sugar matrix, while the other two were independent of the plasticization of the matrix. This finding provides an explanation for the paradoxical fact that compression at several hundreds of MPa significantly decreases the equilibrium water content at a given RH, while the T-g remains unchanged. (C) 2011 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.carres.2011.12.021

Rod-shaped Hydroxyapatite Nanoparticle Formation by Maturation with AOT 査読

Jun Oshitani, Nobuhide Kataoka, Mikio Yoshida, Kuniaki Gotoh, Koreyoshi Imamura

CHEMISTRY LETTERS 40 ( 10 ) 1085 - 1086 2011年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CHEMICAL SOC JAPAN

Amorphous calcium phosphate nanoparticles were synthesized by mixing aqueous solutions of Ca(NO3)(2) and (NH4)(2)-HPO4. Then the particles were matured with sodium bis-(2-ethylhexyl) sulfosuccinate (AOT) at various temperatures. Rod-shaped hydroxyapatite (HAp) nanoparticles were formed at maturation temperature >= 40 degrees C. These results indicate that addition of AOT nor during the particles synthesis but during the maturation at more equal critical temperature is a key to form the rod-shaped HAp nanoparticles using AOT.

DOI： 10.1246/cl.2011.1085

Cloning and expression of a β-galactosidase gene of Bacillus circulans. 査読

Song J, Imanaka H, Imamura K, Minoda M, Katase T, Hoshi Y, Yamaguchi S, Nakanishi K

Bioscience, biotechnology, and biochemistry 75 ( 6 ) 1194 - 1197 2011年6月

Rod-shaped Hydroxyapatite Nanoparticle Formation Using AOT and Water without Oil 査読

Jun Oshitani, Nobuhide Kataoka, Mikio Yoshida, Kuniaki Gotoh, Koreyoshi Imamura, Hidekazu Tanaka

CHEMISTRY LETTERS 40 ( 4 ) 400 - 401 2011年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CHEMICAL SOC JAPAN

We synthesized rod-shaped hydroxyapatite (HAp) nanoparticles using sodium bis(2-ethylhexyl) sulfosuccinate (AOT) as an additive in water without an oil. The length of the particles increases from 40 to 100 nm with increasing the concentration ratio AOT/Ca while maintaining a width of 12 nm. These results indicate that an oil phase is not necessarily needed to form the rod-shaped HAp nanoparticles using AOT.

DOI： 10.1246/cl.2011.400

Influence of compression on water sorption, glass transition, and enthalpy relaxation behavior of freeze-dried amorphous sugar matrices 査読

Koreyoshi Imamura, Ryo Kagotani, Mayo Nomura, Kazuhiro Tanaka, Kohshi Kinugawa, Kazuhiro Nakanishi

INTERNATIONAL JOURNAL OF PHARMACEUTICS 408 ( 1-2 ) 76 - 83 2011年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

An amorphous matrix comprised of sugar molecules are frequently used in the pharmaceutical industry. The compression of the amorphous sugar matrix improves the handling. Herein, the influence of compression on the water sorption of an amorphous sugar matrix was investigated. Amorphous sugar samples were prepared by freeze-drying, using several types of sugars, and compressed at 0-443 MPa. The compressed amorphous sugar samples as well as uncompressed samples were rehumidified at given RHs, and the equilibrium water content and glass transition temperature (T-g) were then measured. Compression resulted in a decrease in the equilibrium water content of the matrix, the magnitude of which was more significant for smaller sized sugars. Diffusivity of water vapor in the sample was also decreased to one-hundredth by the compression. The T-g value for a given RH remained unchanged, irrespective of the compression. Accordingly, the decrease in T-g with increasing water content increased as the result of compression. The structural relaxation of the amorphous sugar matrices were also examined and found to be accelerated to the level of a non-porous amorphous sugar matrix as the result of the compression. The findings indicate that pores contained in freeze-dried sugar samples interfere with the propagation of structural relaxation. (C) 2011 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.ijpharm.2011.01.052

Causes of the production of multiple forms of β-galactosidase by Bacillus circulans. 査読

Song J, Abe K, Imanaka H, Imamura K, Minoda M, Yamaguchi S, Nakanishi K

Bioscience, biotechnology, and biochemistry 75 ( 2 ) 268 - 278 2011年2月

Multiple States of Sorbed Water Molecules in Amorphous Sugar Matrix andtheir Different Impacts on Physical Properties of the Matrix 査読

Koreyoshi Imamura

japan journal of food engineering 12 ( 1 ) 1 - 9 2011年

記述言語：英語掲載種別：研究論文（学術雑誌）

Amorphous materials, comprised of sugar molecules, exhibit high hygroscopicity and the sorbed water exerts a major influence on physical stability of the matrix. To date, the water sorption behavior of amorphous sugars has been extensively investigated. However, most studies of the behavior of water, when sorbed to an amorphous sugar matrix, have implicitly assumed that all of the sorbed water molecules are in a single state: It is naturally expected that the random allocation and configuration of sugar molecules would result in heterogeneity of states for the sorbed water. Recently, we demonstrated the heterogeneity of state and functionality of water sorbed in amorphous sugar matrices by combining a Fourier transform IR spectroscopy and Fourier self-deconvolution technique
The sorbed water molecules were classified into five states, and the three of them mainly served to lower the glass transition temperature of an amorphous sugar matrix while the other two appeared to be independent of physical properties of the matrix. © 2011, Japan Society for Food Engineering. All rights reserved.

DOI： 10.11301/jsfe.12.1

Water Sorption, Glass Transition, and Protein-Stabilizing Behavior of an Amorphous Sucrose Matrix Combined With Various Materials 査読

Koreyoshi Imamura, Toru Yokoyama, Atsushi Fukushima, Mitsunori Kinuhata, Kazuhiro Nakanishi

JOURNAL OF PHARMACEUTICAL SCIENCES 99 ( 11 ) 4669 - 4677 2010年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：JOHN WILEY & SONS INC

The effects of various additives on the physical properties of an amorphous sugar matrix were compared. Amorphous, sugar-additive mixtures were prepared by freeze-drying and then rehumidified at given RHs. Sucrose and eighteen types of substances were used as the sugar and the additive, respectively, and water sorption, glass-to-rubber transition, and protein stabilization during freeze-drying for the various sucrose-additive mixtures were examined. The additives were categorized into two groups according to their effects on T(g) and water sorption. Presence of polysaccharides, cyclodextrins, and polymers (large-sized additives) resulted in a decrease in equilibrium water content from the ideal value calculated from individual water contents for sucrose and additive, and in contrast, low MW substances containing ionizable groups (small-ionized additives) resulted in an increase. The increase in T(g) by the addition of large-sized additives was significant at the additive contents >50 wt.% whereas the T(g) was markedly increased in the lower additive content by the addition of small-ionized additives. The addition of small-ionized additives enhanced the decrease in T(g) with increasing water content. The protein stabilizing effect was decreased with increasing additive content in the cases of the both groups of the additives. (C) 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:4669-4677, 2010

DOI： 10.1002/jps.22162

Development of a highly efficient indigo dyeing method using indican with an immobilized beta-glucosidase from Aspergillus niger 査読

Jingyuan Song, Hiroyuki Imanaka, Koreyoshi Imamura, Kouichi Kajitani, Kazuhiro Nakanishi

JOURNAL OF BIOSCIENCE AND BIOENGINEERING 110 ( 3 ) 281 - 287 2010年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC BIOSCIENCE BIOENGINEERING JAPAN

A highly efficient method for dyeing textiles with indigo is described. In this method, the substrate, indican is first hydrolyzed at an acidic pH of 3 using an immobilized beta-glucosidase to produce indoxyl, under which conditions indigo formation is substantially repressed. The textile sample is then dipped in the prepared indoxyl solution and the textile is finally exposed to ammonia vapor for a short time, resulting in rapid indigo dyeing. As an enzyme, we selected a beta-glucosidase from Aspergillus niger, which shows a high hydrolytic activity towards indican and was thermally stable at temperatures up to 50-60 degrees C, in an acidic pH region. The A. niger beta-glucosidase, when immobilized on Chitopearl BCW-3001 by treatment with glutaraldehyde, showed an optimum reaction pH similar to that of the free enzyme with a slightly higher thermal stability. The kinetics for the hydrolysis of indican at pH 3, using the purified free and immobilized enzymes was found to follow Michaelis-Menten type kinetics with weak competitive inhibition by glucose. Using the immobilized enzyme, we successfully carried out repeated-batch and continuous hydrolyses of indican at pH 3 when nitrogen gas was continuously supplied to the substrate solution. Various types of model textiles were dyed using the proposed method although the color yield varied, depending on the type of textile used. (C) 2010, The Society for Biotechnology, Japan. All rights reserved.

DOI： 10.1016/j.jbiosc.2010.03.010

Influences of properties of protein and adsorption surface on removal kinetics of protein adsorbed on metal surface by H2O2-electrolysis treatment 査読

Koreyoshi Imamura, Manabu Oshita, Masumi Iwai, Toshiki Kuroda, Ippei Watanabe, Takaharu Sakiyama, Kazuhiro Nakanishi

JOURNAL OF COLLOID AND INTERFACE SCIENCE 345 ( 2 ) 474 - 480 2010年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACADEMIC PRESS INC ELSEVIER SCIENCE

"H2O2-electrolysis" treatment is an alternative method for removing proteinaceous materials that are adsorbed to metal surfaces. The method is based on the generation of hydroxyl radicals by electrolysis of hydrogen peroxide and the subsequent decomposition of organic substances adhering to the metal surface. We herein investigated the influence of some parameters on the kinetics of protein removal by H2O2-electrolysis. These parameters included the properties of proteins and the type of metal surface. Sixteen types of proteins and nine types of metal surfaces were used. The removal of adsorbed protein from a metal surface during the treatment was monitored by ellipsometry. Apparent first-order rate constants for removal, k(cl), for various adsorption and treatment conditions were determined. The k(cl) value varied markedly with the type of protein and was also influenced by the pH used in the adsorption. The isoelectric point (pI) of protein used was found to be a major factor. The amount of adsorbed protein removed by a unit amount of (OH)-O-center dot was larger for a metal surface with a lower pI. The impact of the properties of the protein and metal surface on the removal kinetics are discussed, focusing on relationships with the adsorption characteristics of the protein. (C) 2010 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.jcis.2010.01.083

Impacts of Compression on Crystallization Behavior of Freeze-Dried Amorphous Sucrose 査読

Koreyoshi Imamura, Mayo Nomura, Kazuhiro Tanaka, Nobuhide Kataoka, Jun Oshitani, Hiroyuki Imanaka, Kazuhiro Nakanishi

JOURNAL OF PHARMACEUTICAL SCIENCES 99 ( 3 ) 1452 - 1463 2010年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：JOHN WILEY & SONS INC

An amorphous matrix comprised of sugar molecules is used as excipient and stabilizing agent for labile ingredients in the pharmaceutical industry. The amorphous sugar matrix is often compressed into a tablet form to reduce the volume and improve handling. Herein, the effect of compression on the crystallization behavior of an amorphous sucrose matrix was investigated. Amorphous sucrose samples were prepared by freeze-drying and compressed under different conditions, followed by analyses by differential scanning calorimetry, isothermal crystallization tests, X-ray powder diffractometry, Fourier transform infrared spectroscopy (FTIR), and gas pycnometry. The compressed sample had a lower crystallization temperature and a shorter induction period for isothermal crystallization, indicating that compression facilitates the formation of the critical nucleus of a sucrose crystal. Based on FTIR and molecular dynamics simulation results, the conformational distortion of sucrose molecules due to the compression appears to contribute to the increase in the free energy of the system, which leads to the facilitation of critical nucleus formation. An isothermal crystallization test indicated an increase in the growth rate of sucrose crystals by the compression. This can be attributed to the transformation of the microstructure from porous to nonporous, as the result of compression. (C) 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:1452-1463, 2010

DOI： 10.1002/jps.21890

Cultivation characteristics and gene expression profiles of Aspergillus oryzae by membrane-surface liquid culture, shaking-flask culture, and agar-plate culture 査読

Hiroyuki Imanaka, Soukichi Tanaka, Bin Feng, Koreyoshi Imamura, Kazuhiro Nakanishi

JOURNAL OF BIOSCIENCE AND BIOENGINEERING 109 ( 3 ) 267 - 273 2010年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC BIOSCIENCE BIOENGINEERING JAPAN

We cultivated a filamentous fungus, Aspergillus oryzae IAM 2706 by three different cultivation methods, i.e., shaking-flask culture (SFC), agar-plate culture (APC), and membrane-surface liquid culture (MSLC), to elucidate the differences of its behaviors by different cultivation methods under the same media, by measuring the growth, secretion of proteases and alpha-amylase, secreted protein level, and gene transcriptional profile by the DNA microarray analysis. The protease activities detected by MSLC and APC were much higher than that by SFC, using both modified Czapek-Dox (mCD) and dextrin-peptone-yeast extract (DPY) media. The alpha-amylase activity was detected in MSLC and APC in a much larger extent than that in SFC when DPY medium was used. On the basis of SDS-PAGE analyses and N-terminal amino acid sequences, 6 proteins were identified in the supernatants of the culture broths using DPY medium, among which oryzin (alkaline protease) and alpha-amylase were detected at a much higher extent for APC and MSLC than those for SFC while only oryzin was detected in mCD medium, in accordance with the activity measurements. A microarray analysis for the fungi cultivated by SFC, APC, and MSLC using mCD medium was carried out to elucidate the differences in the gene transcriptional profile by the cultivation methods. The gene transcriptional profile obtained for the MSLC sample showed a similar tendency to the APC sample while it was quite different from that for the SFC sample. Most of the genes specifically transcribed in the MSLC sample versus those in the SFC sample with a 10-fold up-regulation or higher were unknown or predicted proteins. However, transcription of oryzin gene was only slightly up-regulated in the MSLC sample and that of alpha-amylase gene, slightly down-regulated. (C) 2009, The Society for Biotechnology, Japan. All rights reserved.

DOI： 10.1016/j.jbiosc.2009.09.004

低温度領域における糖類アモルファスマトリクスのタンパク質安定化作用と糖分子の束縛状態

今村維克, 横山徹, 大山健一, 絹畠光倫, 今中洋行, 中西一弘

化学工学会研究発表講演要旨集 2010 584 - 584 2010年

各種糖類アモルファスマトリクスに収着した水の状態とガラス転移温度との関係

籠谷亮, 衣川耕史, 野村真世, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2010 583 - 583 2010年

Streptmyces mobaraensis由来epsilon-Lysine acylaseによるN-epsilon-Lauroyl-L-Lysineの効率的合成

内田達也, 田口友造, 今中洋行, 今村維克, 是石真友子, 中西一弘

化学工学会研究発表講演要旨集 2010 1003 - 1003 2010年

クッションタンパク質を用いた機能的ペプチド固定化法の検討

國方俊暢, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2010 997 - 997 2010年

オートトランスポーターを用いたペプチド表層提示系の検討

今中洋行, 植田久子, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2010 165 - 165 2010年

Development of peptide immobilization method using PS-tagged cushion protein 査読

Hiroyuki Imanaka, Daisuke Yamazumi, Toshinobu Kunikata, Koreyoshi Imamura, Kazuhiro Nakanishi

JOURNAL OF BIOSCIENCE AND BIOENGINEERING 108 S161 - S161 2009年11月

Formation characteristics of calcium phosphate deposits on a metal surface by H2O2-electrolysis reaction under various conditions 査読

Kazuaki Kanamoto, Koreyoshi Imamura, Nobuhide Kataoka, Jun Oshitani, Hiroyuki Imanaka, Kazuhiro Nakanishi

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS 350 ( 1-3 ) 79 - 86 2009年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

The cathodic electrolysis of H2O2 (H2O2 + e(-) -> OH- + (OH)-O-center dot) on a metal surface in the presence of calcium and phosphate ions results in the formation of calcium phosphate deposits oil the metal surface. In this Study, the deposits formed under various treatment conditions (pHs, concentrations and ratios of calcium/phosphate ions, and so on) were characterized by scanning electron spectroscopy (SEM). and X-ray diffractometry. The exclusive formation of hydroxyapatite, HAP, was observed under comparatively narrow conditions (pH 3-4, [Ca+]/[PO43-] = 25 mM/15 mM), which is clearly different from the reported conditions for the deposition of HAP on titanium substrates. HAP was deposited in the form of a layer. comprised of morphologically amorphous HAP flakes that were less than 20 nm thick. SEM and FTIR analyses of the deposit at different stages of H2O2-electrolysis revealed that a few dozen nanometer-sized spheres of amorphous calcium phosphate were formed in the first step and then fused with each other to form ribbon-like flakes of HAP or broken glass-like brushite, depending on the pH. The pH for HAP formation oil a stainless steel surface was markedly lower than that used for titanium, and the observed process by which amorphous calcium phosphate is converted to HAP was markedly different from that for the electrochemical deposition (electrolysis of water) of HAP on a titanium substrate. (C) 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.colsurfa.2009.09.007

Temperature Scanning FTIR Analysis of Secondary Structures of Proteins Embedded in Amorphous Sugar Matrix 査読

Koreyoshi Imamura, Ken-Ichi Ohyama, Toru Yokoyama, Yoshinobu Maruyama, Nakanishi Kazuhiro

JOURNAL OF PHARMACEUTICAL SCIENCES 98 ( 9 ) 3088 - 3098 2009年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：JOHN WILEY & SONS INC

Heat-induced changes in secondary structures of five proteins (bovine serum albumin, BSA; human serum albumin, HSA; myoglobin; ribonuclease A, RNase A; and, beta-lactoglobulin, beta-Lg) in an amorphous sugar matrix were analyzed by temperature-scanning Fourier transform infrared spectroscopy to elucidate the mechanism of heat-induced conformational change of solid-phase proteins. Three sugars, trehalose, maltose, and dextran (MW 6000), were used. Loss of alpha-helices due to increasing temperature was observed for BSA, HSA, and myoglobin, which are rich in a-helices. RNase A showed a marked decrease in predominant secondary structural components (beta-sheet) with increasing temperature. However, no noticeable changes in the content of secondary structures, except for a slight loss of alpha-helices, were observed for beta-Lg, which is also beta-sheet-rich. These heat-induced conformational changes were significant at temperatures above the glass transition temperature. The heat-induced conformational change in BSA dried with sugar appeared time-independent and was clearly different from that due to dehydration and from the thermal conformational change for a solution of BSA. In particular, differences in secondary structural components that increased due to loss of alpha-helices were noted. (c) 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:3088-3098, 2009

DOI： 10.1002/jps.21568

Purification, Characterization, Molecular Cloning, and Expression of a New Aminoacylase from Streptomyces mobaraensis That Can Hydrolyze N-(Middle/Long)-chain-fatty-acyl-L-amino Acids as Well as N-Short-chain-acyl-L-amino acids 査読

Mayuko Koreishi, Yasuyuki Nakatani, Manami Ooi, Hiroyuki Imanaka, Koreyoshi Imamura, Kazuhiro Nakanishi

BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY 73 ( 9 ) 1940 - 1947 2009年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：TAYLOR & FRANCIS LTD

We report here on the purification, characterization, molecular cloning, and expression of a new aminoacylase, initially isolated from the supernatant of Streptomyces mobaraensis (Sm-AA). Purified wild-type Sm-AA was found to be a monomeric protein with a molecular mass of 55kDa. The cloned gene of Sm-AA contained an ORF of 1,383 bp, encoding a polypeptide of 460 amino acids. A BLAST search revealed that Sm-AA belongs to the peptidase M20 family, with identities to a hypothetical protein from Streptomyces pristinaespiralis, a putative peptidase from Streptomyces averinitilis, peptidase M20 from Frankia sp., succinyl-diaminopimelate desuccinylase from Hemophilus influenzae, and aminoacylase-1 from porcine kidney at 89, 88, 67, 29, and 25% respectively. The Sm-AA gene was subcloned into an expression vector, pSH19, and was expressed in Streptomyces lividans TK24. The amount of the recombinant Sm-AA expressed in the S. lividans cells was approximately 42-fold higher than that of Sm-AA found in the supernatant of S. mobaraensis. Sm-AA showed high hydrolytic activity towards various N-acetyl-L-amino acids and N-(middle/long)-chain-fatty-acyl-L-amino acids, with a preference for the acyl derivatives of L-Met, L-Ala, L-Cys, etc. with an optimum pH and temperature for reaction of about 7.5 and 50 degrees C (at pH 7.5).

DOI： 10.1271/bbb.90081

Efficient N epsilon-lauroyl-L-lysine production by recombinant epsilon-lysine acylase from Streptomyces mobaraensis 査読

Mayuko Koreishi, Ryoko Kawasaki, Hiroyuki Imanaka, Koreyoshi Imamura, Yasuaki Takakura, Kazuhiro Nakanishi

JOURNAL OF BIOTECHNOLOGY 141 ( 3-4 ) 160 - 165 2009年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

epsilon-Lysine acylase from Streptomyces mobaraensis (Sm-ELA), which specifically catalyzes hydrolysis of the epsilon-amide bond in various N epsilon-acyl-L-lysines, was cloned and sequenced. The Sm-ELA gene consists of a 1617-bp open reading frame that encodes a 538-amino acid protein with a molecular mass of 55,816 Da. An NCBI protein-protein BLAST search revealed that the enzyme belongs to the YtcJ-like metal-dependent amidohydrolase family, which is further characterized as the metallo-dependent hydrolase superfamily. The Sm-ELA gene was ligated into a pUC702 vector for expression in Streptomyces lividans TK24. Expression of recombinant Sm-ELA in S. lividans was approximately 300-fold higher than that in wild-type S. mobaraensis. The recombinant Sm-ELAs from the cell-free extract and Culture supernatant were purified to homogeneity. The specific activities of the purified Sm-ELAs were 2500-2800 U/mg, which were similar to that obtained for the wild-type Sm-ELA. Using the cell-free extract of the recombinant S. lividans cells, N epsilon-lauroyl-L-lysine was synthesized from 500 mM L-lysine hydrochloride and 50, 100, or 250 mM lauric acid in an aqueous buffer Solution at 37 degrees C. The yields were close to 100% after 6 and 9 1) of reaction for 50 and 100 mM lauric acid, respectively. and 90% after 24 h for 250 mM lauric acid. (C) 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jbiotec.2009.03.008

糖類アモルファス材料の水分収着特性とタンパク質安定化作用に及ぼす高圧処理の影響

今村維克, 野村真世, 木村佳文, 伊久珠代, 絹畠光倫, 今中洋行, 中西一弘

化学工学会研究発表講演要旨集 2009 779 - 779 2009年

クッションタンパク質を利用したバイオ分子固定化技術の開発と応用

麻那古秀友, 山隅大輔, 大塚隆尚, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2009 1060 - 1060 2009年

PS-tag連結タンパク質を利用したバイオ分子間相互作用解析

今中洋行, 上崎英範, 國方俊暢, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2009 934 - 934 2009年

オートトランスポーターを用いたバイオ分子表層提示系

今中洋行, 植田久子, 山下麻衣, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2009 606 - 606 2009年

糖類アモルファスマトリクスにおける糖-高分子間相互作用の形成特性

今村維克, 横山徹, 大山健一, 野村真世, 今中洋行, 中西一弘

化学工学会研究発表講演要旨集 2009 608 - 608 2009年

Recent advances in controlled immobilization of proteins onto the surface of the solid substrate and its possible application to proteomics 査読

Kazuhiro Nakanishi, Takaharu Sakiyama, Yoichi Kumada, Koreyoshi Imamura, Hiroyuki Imanaka

Current Proteomics 5 ( 3 ) 161 - 175 2008年10月

記述言語：英語

Proteome analysis plays a key role in the elucidation of the functions and applications for numerous proteins. For proteome analyses, various microplate- and microarray-based techniques have been developed by a number of researchers. Their intent was to immobilize proteins on the surface of a solid substrate in a site-directed manner while retaining structure and native biological function. In this review, we focus on recent advances in immobilization methodology for proteins/enzymes on a surface, including those using the affinity peptides screened by random peptide library systems. We also discuss applications of the affinity peptide-mediated immobilization method in fields related to proteome analysis, particularly our recent work concerning immunoassay and protein-protein interaction analysis. ©2008 Bentham Science Publishers Ltd.

DOI： 10.2174/157016408785909622

Adsorption Characteristics of Various Proteins to a Titanium Surface 査読

Koreyoshi Imamura, Miyuki Shimomura, Shungo Nagai, Megumi Akamatsu, Kazuhiro Nakanishi

JOURNAL OF BIOSCIENCE AND BIOENGINEERING 106 ( 3 ) 273 - 278 2008年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC BIOSCIENCE BIOENGINEERING JAPAN

Adsorption characteristics of 18 proteins, with different sizes and isoelectric points, to a titanium oxide surface were studied. The adsorption isotherms were categorized based on protein type and pH: type 1, irreversible adsorption; type 2, Langmuir-type reversible adsorption; and type 3, reversible and irreversible adsorption. Most of the proteins tested were irreversibly adsorbed in the pH range of 3-8, whereas most adsorbed reversibly at pH 8.5-9.4. Protamine, with a pI value of 12, adsorbed reversibly in the pH range of 3-9. pH values that gave maximal sums of irreversibly and reversibly adsorbed proteins were in the pH range of 3-8 and tended to increase slightly with the pI value of the corresponding protein. pH values that gave maximal quantities of irreversibly adsorbed protein ranged between 4-6 and were nearly independent of pI.

DOI： 10.1263/jbb.106.273

True density analysis of a freeze-dried amorphous sugar matrix 査読

Koreyoshi Imamura, Yoshinobu Maruyama, Kazuhiro Tanaka, Tohru Yokoyama, Hiroyuki Imanaka, Kazuhiro Nakanishi

JOURNAL OF PHARMACEUTICAL SCIENCES 97 ( 7 ) 2789 - 2797 2008年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：JOHN WILEY & SONS INC

True density of an amorphous matrix represents the state of molecular packing in the matrix, which is closely related to the physical/chemical properties of the material. Dry gas pycnometry is one possible technique for measuring the true density of an amorphous sugar matrix prepared by freeze-drying. We herein report on the influence of conditions used for pycnometry on the measured density value and propose a protocol for obtaining the true density. The technique is sufficiently accurate to permit values for matrices comprised of different types of sugar to be compared. Using the protocol, the true densities of several amorphous sugar samples containing different types of sugar, freeze-drying conditions (temperature and sugar concentration at the time of freezing of an aqueous sugar solution), pretreatment (compaction and grind) were determined and the results were compared. A model for simulating an amorphous matrix of sugar (trehalose) was constructed using molecular dynamics/mechanics calculations, and the true density of the simulated sugar matrix was found to agree with the value experimentally determined using the proposed protocol. The relationship among the true density, the states of intermolecular interactions, and strain of sugar molecules in the matrix are discussed using the simulated amorphous sugar matrix. (C) 2007 Wiley-Liss, Inc.

DOI： 10.1002/jps.21202

Characteristics of hydrogen bond formation between sugar and polymer in freeze-dried mixtures under different rehumidification conditions and its impact on the glass transition temperature 査読

Koreyoshi Imamura, Yoko Asano, Yoshinobu Maruyama, Tohru Yokoyama, Mayo Nomura, Seiji Ogawa, Kazuhiro Nakanishi

JOURNAL OF PHARMACEUTICAL SCIENCES 97 ( 3 ) 1301 - 1312 2008年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：JOHN WILEY & SONS INC

The characteristics of hydrogen bond formation between trehalose and polyvinylpyrrolidone (PVP) in amorphous mixtures at different hydration states were quantitatively investigated. Amorphous trehalose-PVP mixtures were prepared by freeze-drying and equilibrated at different relative humidities (RH). Infrared (IR) spectra of the trehalose-PVP mixtures were obtained by Fourier transform IR spectroscopy,(FTIR) and the IRband corresponding to C=O groups of PVP was deconvolved into the component bands responsible for C=O groups that were free and restricted by hydrogen bonds, to estimate the degree of the trehalose-PVP interactions. The FTIR analysis indicated that approximately 80% of the C=O groups of PVP formed hydrogen bonds with trehalose in the presence of more than 3 g of trehalose per gramme of PVP, independent of the RH. IR analysis of the O-H stretching vibration of the sugar demonstrated that the presence of PVP lead to an increase in the free hydroxyl groups of trehalose that did not form hydrogen bonds at RH 0%. On the other hand, the water sorption behavior of the trehalose-PVP mixtures suggested that rehumidification diminished the effect of PVP on increasing the free OH groups. Thus a peculiar relationship may exist between T-g, RH and the composition of the mixture: The presence of PVP increased T-g at RHs 0 and above 23% but decreased T-g at 11%. (C) 2007 Wiley-Liss, Inc.

DOI： 10.1002/jps.21066

Temperature scanning FTIR analysis of interactions between sugar and polymer additive in amorphous sugar-polymer mixtures 査読

Koreyoshi Imamura, Ken-Ichi Ohyama, Toru Yokoyama, Yoshinobu Maruyama, Hiroyuki Imanaka, Kazuhiro Nakanishi

JOURNAL OF PHARMACEUTICAL SCIENCES 97 ( 1 ) 519 - 528 2008年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：JOHN WILEY & SONS INC

The impact of a polymer additive (polyvinylpyrrolidone, PVP) on hydrogen bonding in amorphous sugar matrices as well as on the glass transition temperature, T-g, were examined by temperature scanning Fourier transform infrared spectroscopy (TS-FTIR). An amorphous sugar matrix containing PVP was prepared by air-drying an aqueous solution of a sugar-PVP mixture. The hydrogen bonds in the sugar-PVP mixture (sugar-PVP and sugar-sugar hydrogen bonds) were analyzed from the IR peak positions corresponding to the stretching vibration of C=O groups of PVP and O-H groups of the sugar and the temperature dependence of the peak position of the O-H stretching vibration band. The addition of PVP to amorphous mono and disaccharides significantly lowered the extent of hydrogen bond formation while interactions between sugars and the PVP tended to prevent the disruption of hydrogen bonds due to increasing temperature, the magnitude of which was larger for larger oligomers. The T-g value for the amorphous sugar was increased by the addition of PVP in many cases. As the size of sugar molecule became larger, the relative magnitude of the increased T-g by PVP to the difference between the T-g values for sugar alone and PVP alone became larger and then reached a certain level; it was slight in the case of glucose. Collectively, these results demonstrate that the magnitude of the impact of PVP on an amorphous sugar matrix strongly vary and are dependent on the types of sugar. (C) 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:519-528, 2008.

DOI： 10.1002/jps.21075

Fourier self-deconvolution analysis of hydrogen bonding states of polyvinylpyrrolidone in an amorphous sugar matrix below and above the glass transition temperature 査読

Koreyoshi Imamura, Ken-ichi Ohyama, Kazuko Tani, Toru Yokoyama, Yoshinobu Maruyama, Hiroyuki Imanaka, Kazuhiro Nakanishi

SPECTROSCOPY LETTERS 41 ( 6 ) 305 - 312 2008年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：TAYLOR & FRANCIS INC

In an amorphous mixture of sugar and polyvinylpyrrolidone (PVP), PVP carbonyl groups form hydrogen bonds with sugar hydroxyl groups, thereby improving the physical stability of the amorphous matrix against a glass-to-rubber transition. Herein, Fourier self-deconvolved IR bands due to the C=O stretching vibration of PVP in sugar-PVP mixtures were analyzed. The C=O groups in sugar-PVP mixtures generally had four vibrational states, corresponding with free and hydrogen-bonded C=O in three different modes. Changes in these vibrational states induced by increasing the temperature were compared among various sugar-PVP mixtures. Formation and thermal disruption characteristics of different modes of sugar-PVP hydrogen bondings are discussed.

DOI： 10.1080/00387010802370959

過酸化水素の電気分解を利用した金属表面の洗浄技術であるH₂O₂-電気分解洗浄の洗浄特性に及ぼす諸因子の影響

今村維克

日本食品工学会誌 9 ( 4 ) 229 - 238 2008年

出版者・発行元：日本食品工学会

著者らは汚れの付着した金属表面上で集中的にOHラジカル (・OH) を発生させることを原理とする新たな洗浄手法を開発した.すなわち, 過酸化水素を含む水溶液に汚れの付着した金属表面を浸し, その状態で負電位を印加する.H₂O₂分子が金属表面で電子を受け取ることにより, きわめて酸化力が高い・OHが発生し, 汚れ物質を速やかに酸化分解し, 金属表面から除去することができる.すでに, タンパク質をモデル汚れ物質として, H₂O₂-電気分解洗浄における洗浄機構と有効性を検証している.本稿では, H₂O₂-電気分解洗浄における諸因子の影響の把握と洗浄効率のさらなる効率化を図るため, (1) 支持電解質の種類および濃度の影響, (2) 基板材質の影響, (3) 吸着物質 (タンパク質および脂質) の種類の影響, (4) 共存物質の影響について検討した.その結果, H₂O₂-電気分解洗浄においてアンモニウム化合物やリン酸イオンが存在するとモデル汚れ物質 (タンパク質) の除去速度が格段に向上することを明らかにした.また, 各種モデル汚れ物質や基板材質に対する有効性についても検証した.

DOI： 10.11301/jsfe2000.9.229

高圧処理における糖類アモルファスマトリクスの物理特性変化

今村維克, 野村真世, 横山徹, 今中洋行, 中西一弘

化学工学会研究発表講演要旨集 2008 339 - 339 2008年

膜面液体培養法を用いた麹菌の培養特性及び遺伝子発現

田中創吉, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2008 378 - 378 2008年

親和性ペプチドを利用したポリスチレンおよびガラス表面への蛋白質固定化とその利用

今中洋行, 上崎英範, 石村遼太, 熊田陽一, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2008 345 - 345 2008年

クッションタンパク質を利用したバイオ分子固定化技術の開発

山隅大輔, 柳田圭介, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2008 418 - 418 2008年

糖類アモルファスマトリクスの包括安定化作用および物理的諸特性に及ぼす高圧処理の影響

今村維克, 野村真世, 田中一宏, 木村佳文, 今中洋行, 中西一弘

化学工学会研究発表講演要旨集 2008 175 - 175 2008年

ヒト由来転写因子とDNAとの相互作用解析システムの検討

今中洋行, 前川真光, 今村維克, 近藤英作, 中西一弘

化学工学会研究発表講演要旨集 2008 955 - 955 2008年

TPR domain of Ser/Thr phosphatase of Aspergillus oryzae shows no auto-inhibitory effect on the dephosphorylation activity 査読

Bin Feng, Chun-Hui Zhao, Soukichi Tanaka, Hiroyuki Imanaka, Koreyoshi Imamura, Kazuhiro Nakanishi

INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES 41 ( 3 ) 281 - 285 2007年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

A Ser/Thr phosphatase gene cloned from Aspergillus oryzae, aoppt, revealed that the tetratricopeptide repeat (TPR) and catalytic domains of the full-length AoPPT are located at the N- and C-terminal regions, respectively, similar to those of human Ser/Thr phosphatase 5 (PP5) and yeast Ppt1. Four different regions of AoPPT, namely, a full-length polypeptide, the catalytic domain, the catalytic domain plus C-terminal 15 amino-acid residues and the TPR domain were expressed in Escherichia coli and their roles in dephosphorylation activity were examined, using p-nitrophenyl phosphate as the substrate. The full-length AoPPT showed the highest dephosphorylation activity while the catalytic domain had the lowest activity. The activity of the catalytic domain was not inhibited by the presence of the TPR domain and arachidonic acid did not increase the activity of the full-length enzyme. These findings suggest that the integrity of the entire enzyme would be necessary for its full activity to be expressed. (c) 2007 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.ijbiomac.2007.03.005

Enzymatic synthesis of beta-lactam antibiotics and N-fatty-acylated amino compounds by the acyl-transfer reaction catalyzed by penicillin V acylase from Streptomyces mobaraensis 査読

Mayuko Koreishi, Kazuha Tani, Yuuichi Ise, Hiroyuki Imanaka, Koreyoshi Imamura, Kazuhiro Nakanishi

BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY 71 ( 6 ) 1582 - 1586 2007年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：TAYLOR & FRANCIS LTD

Penicillin V acylase from Streptomyces mobaraensis (Sm-PVA) showed high acyl-transfer activity in reactions using methyl esters of carboxylic acid (acyl donor) and amino compounds (nucleophile), to produce the corresponding amides. Moreover, Sm-PVA had broad substrate specificity, as indicated by the fact that it catalyzed the efficient synthesis of fl-lactam antibiotics, capsaicin derivatives, and N-fatty-acyl-amino acid/N-fatty-acyl-peptide derivatives.

DOI： 10.1271/bbb.70052

Cloning and characterization of penicillin V acylase from Streptomyces mobaraensis 査読

Demin Zhang, Mayuko Koreishi, Hiroyuki Imanaka, Koreyoshi Imamura, Kazuhiro Nakanishi

JOURNAL OF BIOTECHNOLOGY 128 ( 4 ) 788 - 800 2007年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

We report on the molecular cloning and characterization of penicillin V acylase (PVA) from an actinomycete, Streptomyces mobaraensis (Sm-PVA), which was originally isolated as an acylase that efficiently hydrolyzes the amide bond of various N-fatty-acyl-L-amino acids and N-fatty-acyl-peptides as well as capsaicin (8-methyl-N-vanillyl-6-nonenamide). In addition, the purified Sm-PVA hydrolyzed penicillin V with the highest activity (k(cat)) among the PVAs so far reported, penicillin G, and 2-nitro-5-phenoxyacetamide benzoic acid. The BLAST search revealed that the Sm-PVA precursor is composed of a polypeptide that is characteristic of enzymes belonging to the beta-lactam acylase family with four distinct segments; a signal sequence (43 amino acids), an a subunit (173 amino acids), a linker peptide (28 amino acids), and a beta subunit (570 amino acids). The mature, active Sm-PVA is a heterodimeric protein with alpha and beta subunits, in contrast to PVAs isolated from Bacillus sphaericus and B. subtilis, which have a homotetrameric structure. The amino acid sequence of Sm-PVA showed identities to PVA from S. lavendulae, N-acylhomoserine lactone-degrading acylase from Streptomyces sp., cyclic lipopeptide acylase from Streptomyces sp., and aculeacin A acylase from Actinoplanes utahensis with 68, 67, 67, and 41% identities, respectively. (c) 2007 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jbiotec.2006.12.017

Protein-protein interaction analysis using an affinity peptide tag and hydrophilic polystyrene plate 査読

Yoichi Kumada, Chunhui Zhao, Ryota Ishimura, Hiroyuki Imanaka, Koreyoshi Imamura, Kazuhiro Nakanishi

JOURNAL OF BIOTECHNOLOGY 128 ( 2 ) 354 - 361 2007年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

A sandwich ELISA method using peptide tags showing a specific affinity to a hydrophilic polystyrene surface (PS-tags), PS 19 composed of RAFIASRRIKRP and KPS19R10 of KRAFIASRRIRRP and a hydrophilic polystyrene (phi-PS) plate was used to analyze protein-protein interactions. An Escherichia coli cysteine synthase complex, in which serine acetyltransferase (SAT) interacts with O-acetylserine sulfhydrylase-A (OASS) was used as a model system. When the interaction was detected by the conventional sandwich ELISA method using a hydrophobic polystyrene (pho-PS) plate, for the exclusive use of ELISA, the signal intensity was barely detectable due to conformational change of the ligand protein, OASS in the adsorbed state. On the contrary, when OASS, genetically fused with PS19 (OASS-PS19) or chemically conjugated with KPS19R10 (OASS-KPS19R10), was immobilized on the phi-PS plate, a high signal intensity was detected. Furthermore, by applying the two-step sandwich ELISA, in which OASS-PS19 or OASS-KPS19R10 formed a complex with SAT in the blocking solution before immobilization on the phi-PS plate, the signal intensity was further increased with a much shorter operational time, because SAT in the blocking solution formed a complex with OASS-PS19 or OASS-KPS19R10 without any steric hindrance. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jbiotec.2006.09.018

Adsorption characteristics of oligopeptides composed of acidic and basic amino acids on titanium surface 査読

Koreyoshi Imamura, Yuuki Kawasaki, Takeshi Nagayasu, Takaharu Sakiyama, Kazuhiro Nakanishi

JOURNAL OF BIOSCIENCE AND BIOENGINEERING 103 ( 1 ) 7 - 12 2007年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC BIOSCIENCE BIOENGINEERING JAPAN

The adsorption characteristics of octapeptides, containing different numbers of aspartic acid, lysine, and alanine residues (i.e., D(4)K(0)A(4), D(4)K(1)A(3), D(4)K(3)A(1), D(4)K(4)A(0), and D(0)K(4)A(4)) on the surface of titanium (Ti) particles were investigated in the pH range of 3.0-8.8 at 30 degrees C. The adsorption isotherms for octapeptides having four plural aspartic acid residues with or without lysine residues showed two distinct adsorption modes, i.e., irreversible and reversible modes, at pHs 3.0-6.5; at pH 7.0 or higher, the adsorption mode was reversible. Increasing the number of lysine residues at a fixed number of aspartic acid residues (i.e., 4) decreased the amount of peptides adsorbed in both modes. D(4)K(4)A(0) adsorbed irreversibly at pHs 3.0-6.5, due to the fact that negatively charged carboxyl groups directly interact with a positively charged Ti surface, whereas positively charged amino groups of lysine residues are directed in an opposite direction toward the solution side, as predicted by molecular mechanics/dynamics calculations.

DOI： 10.1263/jbb.103.7

Development of a one-step ELISA method using an affinity peptide tag specific to a hydrophilic polystyrene surface 査読

Yoichi Kumada, Shigeo Katoh, Hiroyuki Imartaka, Koreyoshi Imamura, Kazuhiro Nakanishi

JOURNAL OF BIOTECHNOLOGY 127 ( 2 ) 288 - 299 2007年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

Glutathione S-transferase genetically fused with an affinity peptide tag, PS 19 (RAFIASRRIKRP) having a specific affinity for a hydrophilic polystyrene (PS) surface, was preferentially immobilized on a hydrophilic PS (phi-PS) plate without suffering from interference by coexisting protein molecules. Furthermore, rabbit IgG chemically conjugated with a peptide, KPS 19R10, in which (10)Lys in PS 19 was replaced with Arg and one Lys residue was added at the N-terminus as a coupling site for glutaraldehyde, showed a higher immobilization affinity to the phi-PS plate than that conjugated with the PS 19 peptide. On the basis of these findings, the use of a phi-PS plate and peptide tag-linked ligand proteins permitted a one-step or two-step enzyme-linked immumosorbent assay (ELISA) to be achieved, resulting in a substantial reduction in operational time compared with the conventional ELISA method using a hydrophobic PS (pho-PS) plate, while maintaining a high sensitivity. Furthermore, the sensitivity was increased to a greater extent compared to the conventional ELISA meihod when the one-step ELISA was applied to the detection of bovine insulin in a sandwich mode, due to the reduced number of washing and incubation steps. The method proposed here would be a versatile method for use in various ELISA techniques such as sandwich and competitive ELISAs using an antigen, an antibody and streptavidin that are genetically fused or chemically conjugated with the PS-specific affinity peptide as the ligand protein. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jbiotec.2006.07.011

オートトランスポーターを利用した異種タンパク質の大腸菌細胞表層提示系の構築

今中洋行, 山下麻衣, 盛永鈴香, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2007 417 - 417 2007年

PS-tagを用いたタンパク質間相互作用の検出

熊田陽一, Zhao Chunhui, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2007 427 - 427 2007年

糖-高分子複合アモルファスマトリクスにおける分子間相互作用と物理的安定性

今村維克, 浅野容子, 大山健一, 丸山佳伸, 崎山高明, 今中洋行, 中西一弘

化学工学会研究発表講演要旨集 2007 368 - 368 2007年

過酸化水素-電気分解における金属表面でのハイドロキシアパタイト相の形成とその特性評価

金本和明, 今村維克, 片岡信秀, 押谷潤, 今中洋行, 中西一弘

化学工学会研究発表講演要旨集 2007 126 - 126 2007年

H2O2-電気分解による金属表面および水溶液中の有機物質の分解・除去

今村維克, 黒田俊樹, 小崎正晴, 今中洋行, 中西一弘

化学工学会研究発表講演要旨集 2007 702 - 702 2007年

オートトランスポーターを用いた大腸菌細胞表層提示系に及ぼすシグナルペプチドの影響

今中洋行, 辰本渉, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2007 842 - 842 2007年

大腸菌由来Cysteine synthaseの複合体形成特性

今中洋行, 森賀雄大, 趙春暉, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2007 841 - 841 2007年

過酸化水素-電気分解により生成したハイドロキシアパタイトの特性評価および骨芽様細胞の増殖・分化特性

今村維克, 金本和明, 今中洋行, 中西一弘

化学工学会研究発表講演要旨集 2007 990 - 990 2007年

Identification of genes from Aspergillus oryzae that are preferentially expressed in membrane-surface liquid culture 査読

Bin Feng, Masakazu Morita, Hiroyuki Imanaka, Koreyoshi Imamura, Kazuhlro Nakanishi

JOURNAL OF BIOSCIENCE AND BIOENGINEERING 102 ( 5 ) 470 - 473 2006年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC BIOSCIENCE BIOENGINEERING JAPAN

We identified 22 genes from Aspergillus oryzae that are preferentially expressed in membrane-surface liquid culture (MSLC), among which Ser/Thr protein kinase (aopk1) and phosphatase (aoppt) genes were cloned. We also revealed that aopk1 encodes a protein with an N-terminal sequence 150 amino acid residues longer than that predicted from the registered sequence in GenBank.

DOI： 10.1263/jbb.102.470

Effects of the supporting electrolyte on the kinetics of the removal of proteins adsorbed on a stainless steel surface by H2O2-electrolysis 査読

Koreyoshi Imamura, Ippei Watanabe, Takaharu Sakiyama, Kazuhiro Nakanishi

LANGMUIR 22 ( 16 ) 7035 - 7040 2006年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

The effects of different types of supporting electrolytes on the removal of beta-lactoglobulin (beta-Lg) after being adsorbed to a stainless steel surface by a H2O2-electrolysis treatment was investigated. In this process, hydroxyl radicals (center dot OH), generated by the electrolysis of hydrogen peroxide, decompose the substances adhering to the surface. The removal of the adsorbed protein from the stainless steel surface during the treatment was monitored in situ by ellipsometry. The apparent first-order removal rate constants, k(cl), for 17 types of supporting electrolytes were determined, as well as the current corresponding to the rate of generation of center dot OH. The kcl and generated current values for LiCl, NaCl, KCl, KNO3, K2SO4, CH3COOK, and K2CO3 were all similar. Ca2+ and Mg2+ strongly suppressed the removal of the adsorbed protein. The presence of ammonium compounds led to an increase in kcl and current values. In H2O2-electrolysis in the presence of potassium phosphate, the removal was extremely rapid, and an apparent increase in the thickness of the adsorbed layer was observed. The mechanisms responsible for the peculiar effects of calcium, magnesium, phosphate, and ammonium compounds were investigated by means of a Fourier transform infrared (FTIR) spectroscopic analysis, as well as by the characteristics of the removal under different treatment conditions.

DOI： 10.1021/la053494s

Temperature scanning FTIR analysis of hydrogen bonding states of various saccharides in amorphous matrixes below and above their glass transition temperatures 査読

Koreyoshi Imamura, Keisuke Sakaura, Ken-ichi Ohyama, Atsushi Fukushima, Hiroyuki Imanaka, Takaharu Sakiyama, Kazuhiro Nakanishi

JOURNAL OF PHYSICAL CHEMISTRY B 110 ( 31 ) 15094 - 15099 2006年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

Temperature scanning Fourier transform infrared, TS-FTIR, spectroscopy of various amorphous sugar matrixes was conducted to investigate the relationship between the glass transition temperature, T-g, of an amorphous sugar matrix and the nature of the hydrogen bonds in the matrix. An amorphous sugar matrix was prepared by air-drying an aqueous solution of sugar, and the degree of formation of hydrogen bonds in the matrix was evaluated at different temperatures using the peak positions of the IR band corresponding to the O-H stretching vibration at around 3400 cm(-1). The T-g value increased with increasing peak position of the O-H stretching vibration at T-g and were correlated reasonably well with the magnitude of the peak shift by the temperature increase (from 25 degrees C) to the T-g value. This demonstrates that the amorphous sugar matrix, in which the segments are fixed by fewer hydrogen bonds, has a higher thermal resistance. The glycosidic linkage largely contributes to the restriction of the segments, pyranose ring, rather than a hydrogen bond. As the degree of polymerization of pyranose rings increases, the degree of hydrogen bond formation needed to hold the matrix in a fixed position decreases. However, the magnitude of the restriction of pyranose rings by a glycosidic linkage changes depending on the type: the restrictions imposed by alpha-1,1 and -1,6 glycosidic linkages are the tightest and most flexible of all of the types of glycosidic linkages, respectively.

DOI： 10.1021/jp057527o

Cloning, overexpression, purification, and characterization of O-acetylserine sulfhydrylase-B from Escherichia coli 査読

C Zhao, Y Kumada, H Imanaka, K Imamura, K Nakanishi

PROTEIN EXPRESSION AND PURIFICATION 47 ( 2 ) 607 - 613 2006年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACADEMIC PRESS INC ELSEVIER SCIENCE

O-Acetylserine sulfhydrylase-B (OASS-B, EC 2.5.1.47) is one of the two isozymes produced by Escherichia coli that catalyze the synthesis Of L-Cysteine from O-acetyl- L-serine and sulfide. The cysM gene encoding OASS-B was cloned and the enzyme was overexpressed in E coli using pUC19 with a lacUV5 promoter. The enzyme was purified to homogeneity, as evidenced by SDS-PAGE. Approximately 300 mg of purified OASS-B was obtained from 1600 mL of culture broth with a purification yield of 60% or higher. The purified OASS-13 was characterized and its properties compared with OASS-A. OASS-13 did not form a complex with E. coli serine acetyltransferase (SAT, EC 2.3.1.30) and showed a wide range of substrate specificity in nonproteinaceous amino acid synthesis. (c) 2006 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.pep.2006.01.002

Protease susceptibility of beta-lactoglobulin adsorbed on stainless steel surface as evidence of contribution of its specific segment to adsorption 査読

Takaharu Sakiyama, Atsuko Aya, Mari Embutsu, Koreyoshi Imamura, Kazuhiro Nakanishi

JOURNAL OF BIOSCIENCE AND BIOENGINEERING 101 ( 5 ) 434 - 439 2006年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC BIOSCIENCE BIOENGINEERING JAPAN

beta-Lactoglobulin (beta-Lg) is a major constituent of fouling deposits in the dairy industry. To determine the interaction between beta-Lg and stainless steel surfaces, beta-Lg irreversibly adsorbed on stainless steel particles was subjected to lysyl endopeptidase treatment and the course of fragmentation was compared with that observed for beta-Lg in solution. The results showed a distinct difference between the courses of fragmentation: a fragment (residues 102-135) was liberated readily from beta-Lg in solution but scarcely from beta-Lg irreversibly adsorbed on stainless steel particles. This result strongly suggests that residues 102-135 include a segment primarily responsible for the interaction of beta-Lg with stainless steel surfaces. This supports our previous results [Sakiyama et al., J. Biosci. Bioeng., 88, 536-541 (1999)] that showed that residues 125-135 of beta-Lg have a strong affinity toward stainless steel surfaces and probably a major contribution to the adsorption of beta-Lg.

DOI： 10.1263/jbb.101.434

Screening and characterization of affinity peptide tags specific to polystyrene supports for the orientated immobilization of proteins 査読

Y Kumada, Y Tokunaga, H Imanaka, K Imamura, T Sakiyama, S Katoh, K Nakanishi

BIOTECHNOLOGY PROGRESS 22 ( 2 ) 401 - 405 2006年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

Dodecapeptides that exhibit a high affinity specific to a polystyrene surface (PS-tags) were screened using an Escherichia coli random peptide display library system, and the compounds were used as a peptide tag for the site-specific immobilization of proteins. The various PS-tags obtained after 10 rounds of biopanning selection were mainly composed of basic and aliphatic amino acid residues, most of which were arranged in close proximity to one another. Mutant-type glutathione S-transferases (GSTs) fused with the selected PS-tags. PS19 (RAFIASRRIKRP) and PS23 (AGLRLKKAAIHR) at their C-terminus, GST-PS19 and GST-PS23, when adsorbed on the PS latex beads had a higher affinity than the wild-type GST, and the specific remaining activity of the immobilized mutant-type GSTs was approximately 10 times higher than that of the wild-type GST. The signal intensity detected for GST-PS19 and GST-PS23 adsorbed on hydrophilic and hydrophobic PS surfaces using an anti-peptide antibody specific for the N-terminus peptide of GST was much higher than that for the wild-type GST. These findings indicate that the mutant-type GSTs fused with the selected peptide tags, PS19 and PS23, could be site-specifically immobilized on the surface of polystyrene with their N-terminal regions directed toward the solution. Thus, the selected peptide tags would be useful for protein immobilization in the construction of enzyme-linked immunosorbent assay (ELISA) systems and protein-based biochips.

DOI： 10.1021/bp050331l

On the interaction site of serine acetyltransferase in the cysteine synthase complex from Escherichia coli 査読

CH Zhao, Y Moriga, B Feng, Y Kumada, H Imanaka, K Imamura, K Nakanishi

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS 341 ( 4 ) 911 - 916 2006年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACADEMIC PRESS INC ELSEVIER SCIENCE

Cysteine synthase from Escherichia coli is a bienzyme complex comprised of serine acetyltransferase (SAT) and O-acetylserine sulfhydrylase A. The site of interaction of a SAT molecule was investigated by gel chromatography and surface plasmon technique using various mutant-type SATs, to better understand the mechanism involved in complex formation. The C-terminus of SAT, Ile 273, along with Glu 268 and Asp 271, was found to be essential for complex formation. The effects of O-acetyl-L-serine and sulfide on the affinity for the complex formation were also studied using a surface plasmon technique. (c) 2006 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.bbrc.2006.01.054

A novel acylase from Streptomyces mobaraensis that efficiently catalyzes hydrolysis/synthesis of capsaicins as well as N-Acyl-L-amino acids and N-acyl-peptides 査読

M Koreishi, DM Zhang, H Imanaka, K Imamura, S Adachi, R Matsuno, K Nakanishi

JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 54 ( 1 ) 72 - 78 2006年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

A novel enzyme that catalyzes efficient hydrolysis of capsaicin (8-methyl-N-vanillyl-6-nonenamide) was isolated from the culture broth of Streptomyces mobaraensis. The enzyme consisted of two dissimilar subunits with molecular masses of 61 and 19 kDa. The enzyme was activated and stabilized in the presence of Co2+. It showed a pH optimum of about 8 and was stable at temperatures of up to 55 degrees C for 1 h at pH 7.8. The specific activity of the enzyme for the hydrolysis of capsaicin was 10(2)-10(4) times higher than those for the enzymes reported to date. In an aqueous/n-hexane biphasic system, capsaicin analogues such as octanoyl, decanoyl, and lauroyl vanillylamides were synthesized from the corresponding fatty acids and vanillylamine at yields of 50% or greater. In addition, the enzyme catalyzed the deacylation of N-lauroyl-L-amino acids and N-lauroyl-L-dipeptides and the efficient synthesis of N alpha-lauroyl-L-lysine, N epsilon-lauroyl-L-lysine, and various N-lauroyl-peptides in aqueous solution in both the absence and the presence of glycerol.

DOI： 10.1021/jf052102k

各種糖分子からなるアモルファスマトリクスの物理的諸特性

今村維克, 丸山佳伸, 横山徹, 大山健一, 今中洋行, 中西一弘

化学工学会研究発表講演要旨集 2006 413 - 413 2006年

ポリスチレン親和性ペプチドを利用したタンパク質間相互作用の分析

熊田陽一, 石村遼太, 上崎英範, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2006 996 - 996 2006年

金属表面へのタンパク質付着配向制御

柳田圭介, 中泉雅人, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2006 1002 - 1002 2006年

放線菌 Streptomyces mobaraensis 由来アシラーゼによる転移反応とその応用

是石真友子, 谷和葉, 伊勢雄一, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2006 949 - 949 2006年

高度な物理的安定性とタンパク質安定化作用を兼ね備えた糖類アモルファスマトリクスの創製

横山徹, 丸山佳伸, 大山健一, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2006 995 - 995 2006年

Purification and characterization of a novel aminoacylase from Streptomyces mobaraensis 査読

M Koreishi, F Asayama, H Imanaka, K Imamura, M Kadota, T Tsuno, K Nakanishi

BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY 69 ( 10 ) 1914 - 1922 2005年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：TAYLOR & FRANCIS LTD

A novel aminoacylase was purified to homogeneity from culture broth of Streptomyces mobaraensis, as evidenced by SDS-polyacrylamide gel electrophoresis (PAGE). The enzyme was a monomer with an approximate molecular mass of 100 kDa. The purified enzyme was inhibited by the presence of 1,10-phenanthroline and activated by the addition of Co2+. It was stable at temperatures of up to 60 degrees C for 1 h at pH 7.2. It showed broad substrate specificity to N-acetylated L-amino acids. It catalyzed the hydrolysis of the amide bonds of various N-acetylated L-amino acids, except for N epsilon-acetyl-L-lysine and N-acetyl-L-proline. Hydrolysis of N-acetyl-L-methionine and N-acetyl-L-histidine followed Michaelis-Menten kinetics with K-m values of 1.3 +/- 0.1 mm and 2.7 +/- 0.1 mm respectively. The enzyme also catalyzed the deacetylation of 7-aminocephalosporanic acid (7-ACA) and cephalosporin C. Moreover, feruloyl-amino acids and L-lysine derivatives of ferulic acid derivatives were synthesized in an aqueous buffer using the enzyme.

DOI： 10.1271/bbb.69.1914

A novel ε-lysine acylase from Streptomyces mobaraensis for synthesis of Nε-acyl-L-lysines 査読

Mayuko Koreishi, Ryoko Kawasaki, Hiroyuki Imanaka, Koreyoshi Imamura, Kazuhiro Nakanishi

Journal of the American Oil Chemists’ Society 82 ( 9 ) 631 - 637 2005年9月

Adsorption characteristics of various organic substances on the surfaces of tantalum, titanium, and zirconium 査読

T Nagayasu, K Imamura, K Nakanishi

JOURNAL OF COLLOID AND INTERFACE SCIENCE 286 ( 2 ) 462 - 470 2005年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACADEMIC PRESS INC ELSEVIER SCIENCE

Adsorption characteristics of carboxylic acids, amines, an octapeptide composed of four L-alanine and four L-aspartic acid residues (Peptide-A(4)D(4)), and beta-lactoglobulin (beta-Lg) on tantalum (Ta), titanium (Ti), and zirconium (Zr) particles were examined at 30 degrees C and in some case, were compared with their adsorption onto SUS316L stainless steel particles (S6L). The adsorption isotherms on the Ta, Ti, and Zr particles could usually be expressed either by a Langmuir-type equation for reversible adsorption or by a modified Langmuir-type adsorption equation including terms for both reversible and irreversible adsorption. The adsorption equilibrium of benzoic acid, benzylamine, and m-xylylenediamine on all the metal surfaces followed a Langmuir-type equation, while those of phthalic acid, mellitic acid, and Peptide-A(4)D(4) could be fitted to the modified Langmuir-type adsorption equation. The adsorption characteristics of different adsorbates on the different surfaces were discussed particularly with reference to the pH dependencies of the q(irrev), q(rev), and K values and the electrostatic properties of the oxidized surface of the metal particles. Fourier transform infrared spectroscopic analyses using a reflection/absorption technique (RA-IR) indicated that phthalic acid and mellitic acid are adsorbed in similar adsorption states irrespective of the type of metal. beta-Lg was adsorbed onto the surfaces principally in an irreversible manner. The desorption behavior of beta-Lg from Ta, Ti, and S6L surfaces was examined, in order to evaluate the extent of interaction between beta-Lg and the metals. (c) 2005 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.jcis.2005.01.023

異なる金属表面への種々の有機物質の吸着挙動の比較

長安武司, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2005 292 - 292 2005年

Enzymatic Synthesis of Non-proteinaceous Amino Acids Catalyzed by Cysteine Synthase Coupled with Acetyl-CoA Regeneration

Zhao Chunhui, Imanaka Hiroyuki, Imamura Koreyoshi, Nakanishi Kazuhiro

化学工学会研究発表講演要旨集 2005 271 - 271 2005年

金属表面に吸着した各種タンパク質のH2O2-電気分解処理における脱離特性と脱離促進因子

今村維克, 尾下学, 岩井真澄, 金本知明, 今中洋行, 中西一弘

化学工学会研究発表講演要旨集 2005 294 - 294 2005年

放線菌 Streptomyces mobaraensis 由来新規アシラーゼの精製・特性解析および合成反応

是石真友子, 川崎涼子, 今中洋行, 今村維克, 中西一弘, 丹尾式希

化学工学会研究発表講演要旨集 2005 270 - 270 2005年

膜面液体培養法を用いた遺伝子組換え麹カビによるNuclease S1生産

森田正和, 安達昇, 奥村敦, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2005 242 - 242 2005年

温度走査フーリエ変換赤外分光分析による糖-高分子複合アモルファスマトリクスにおける分子間相互作用の解析

大山健一, 谷加寿子, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2005 293 - 293 2005年

ポリスチレン親和性ペプチド融合タンパク質の吸着特性とその応用

徳永安秀, 熊田陽一, 今石大輔, 今中洋行, 今村維克, 崎山高明, 中西一弘

化学工学会研究発表講演要旨集 2005f 311 - 311 2005年

Analysis of Differential Gene Expression of Aspergillus oryzae in Membrane-Surface Liquid Culture and Shaking Flask Culture by Subtractive Hybridization

Feng Bin, 森田正和, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2005f 294 - 294 2005年

2'-デオキシアデノシン5'-三リン酸(dATP)の酵素合成に関する反応工学的研究

今中洋行, 矢野慎太郎, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2005f 214 - 214 2005年

Characteristics of alpha-glucosidase production from recombinant Aspergillus oryzae by membrane-surface liquid culture in comparison with various cultivation methods 査読

M Morita, H Shimamura, N Ishida, K Imamura, T Sakiyama, K Nakanishi

JOURNAL OF BIOSCIENCE AND BIOENGINEERING 98 ( 3 ) 200 - 206 2004年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC BIOSCIENCE BIOENGINEERING JAPAN

alpha-Glucosidase was produced using recombinant Aspergillus oryzae by membrane-surface liquid culture (MSLC), a method previously developed by the authors and the results compared with other methods, including shaking flask culture (SFC), agar-plate culture (APC), culture on urethane sponge supports (USC), and liquid surface culture (LSC) to determine possible reasons for the advantageous features of MSLC. When yeast extract was used as a nitrogen source, the amount of enzyme produced by MSLC was 5 or more times higher than those for SFC and LSC, but similar to that using APC. Enzyme production in USC was slightly lower than in MSLC and APC. Cell growth was similar irrespective of the cultivation method used. When NaNO3, a typical inorganic nitrogen source was used, enzyme production in all the cultures was lower than that using yeast extract. However, even using NaNO3, the amount of the enzyme produced by MSLC was 8 to 20 times higher than those by SFC, APC, USC, and LSC. Although Cell growth using NaNO3 was similar to that for yeast extract in MSLC, it was markedly decreased in SFC, APC, and LSC. The reason for the difference in enzyme productivity for various cultivation methods using yeast extract and NaNO3 as a nitrogen source is discussed, on the basis of the experimental findings. The role of the oxygen transfer effect and gene expression levels in enzyme production were also examined.

DOI： 10.1016/S1389-1723(04)00266-X

Production of nonproteinaceous amino acids using recombinant Escherichia coli cells expressing cysteine synthase and related enzymes with or without the secretion of O-acetyl-L-serine 査読

CH Zhao, K Ohno, K Sogoh, K Imamura, T Sakiyama, K Nakanishi

JOURNAL OF BIOSCIENCE AND BIOENGINEERING 97 ( 5 ) 322 - 328 2004年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC BIOSCIENCE BIOENGINEERING JAPAN

beta-(Pyrazol-1-yl)-L-alanine (beta-PA), a model nonproteinaceous amino acid, was specifically synthesized by two methods using recombinant Escherichia coli cells that express cysteine synthase, comprising serine acetyltransferase (SAT) and O-acetylserine sulfhydrylase-A (OASS-A) and related enzymes from E. coli. In the first method (method A), recombinant cells that express wildtype SAT, OASS-A, acetate kinase (AK), and phosphotransacetylase (PTA) showed the highest beta-PA production. beta-PA was produced at 140 mM from 200 MM L-serine and 200 mM pyrazole under optimum conditions. Using the cells expressing SATDeltaC20 (truncated SAT), OASS-A, AK, and PTA, beta-PA was produced at a level of only 80 mM, whereas O-acetyl-serine (OAS) was found to be secreted into the broth. Under optimum conditions, OAS accumulated at levels of around 105 mM from 300 mM L-serine. Thus, in the second method (method B), the secreted OAS was used as the substrate for the syntheses of beta-PA and beta-(triazol-1-yl)-L-alanine (beta-TA). The OAS that accumulated in the broth was efficiently converted to beta-PA and beta-TA at levels of around 90 mM from 105 mM OAS using free OASS-A. In both methods A and B, the addition of glucose was essential for the efficient production of beta-PA and OAS, respectively.

DOI： 10.1016/S1389-1723(04)70213-3

Factors Affecting Performance of Cleaning Technique for Metal Surfaces Based on Electrolysis of Hydrogen Peroxide, H2O2-electrolysis 査読

Koreyoshi Imamura

nihon shokuhin kougakukaishi (japan journal of food engineering) 9 ( 4 ) 229 - 238 2004年

記述言語：英語掲載種別：研究論文（学術雑誌）

We have developed a novel technique for removing organic soilings from metal surfaces using hydroxy radicals (·OH). In the cleaning system, a metal surface fouled with organic soilings is made to contact with an aqueous solution containing hydrogen peroxide and supporting electrolyte. A slightly negative potential is then applied into the metal. The ·OHs, which are generated by the electrolysis of hydrogen peroxide (H2O2+e--ē·OH+OH”) on the metal surface, effectively attack and subsequently remove the adsorbed organic soils. In this study, the removal behavior of model organic soilings (protein) during the H2O2-electrolysis cleaning using different types and concentrations of supporting electrolyte was investigated. The presence of ammonium compounds and potassium phosphate led to marked increase in the removal rate. The influences of the types of metal substrate and adsorbed material on the removal behavior were also investigated, which suggested that the adsorption state of organic soiling on a metal surface strongly affect the removal characteristics. Furthermore, the removal rates in the presence of various organic coexisting materials were investigated. It was found that the removal rate constant was only slightly lowered in many cases. © 2008, Japan Society for Food Engineering. All rights reserved.

DOI： 10.11301/jsfe2000.9.229

Removal Behavior of Protein Adsorbed on Metal Surface by H₂O₂-Electrolysis Treatment

Imamura Koreyoshi, Watanabe Ippei, Aramoto Yumi, Sakiyama Takaharu, Nakanishi Kazuhiro

アジア・太平洋化学工学会議発表論文要旨集 2004 353 - 353 2004年

記述言語：英語出版者・発行元：公益社団法人化学工学会

A novel method for generating hydroxyl radicals, ·OH, was developed, by applying slightly negative electric potentials (-0.2 ∼ -0.8 V vs Ag/AgCl) to the surface of a metal in contact with a hydrogen peroxide solution containing a supporting electrolyte. Namely, ·OH radicals are generated at the surface by the electrolysis of hydrogen peroxide according to the equation, H₂O₂ + e- -> ·OH + OH-. In this study, the kinetics of the removal of a model proteinaceous soiling (ß-lactoglobulin, ß-Lg) adsorbed to a stainless steel surface by the H₂O₂-electrolysis treatment were investigated. The rate of removal of the adsorbed ß-Lg from the stainless steel surface during the treatment was monitored in situ by ellipsometry, and the dependencies of the removal rate on H₂O₂ concentration, the electric potential applied to the surface, and the concentration and type of supporting electrolyte were examined.

DOI： 10.11491/apcche.2004.0.353.0

Production of Non-Proteinaceous Amino Acids using Recombinant E. coli Cells

Nakanishi Kazuhiro, Zhao Chunhui, Imamura Koreyoshi, Ohno Katsuhiro

アジア・太平洋化学工学会議発表論文要旨集 2004 815 - 815 2004年

記述言語：英語出版者・発行元：公益社団法人化学工学会

β-(Pyrazol-1-yl)-L-alanine (β-pyrazole-L-Ala; β-PA), a model non-proteinaceous amino acid was synthesized using recombinant Escherichia coli cells that express cysteine synthase and enzymes that regenerate acetyl-CoA. In Method A, β-PA was synthesized from L-Ser and pyrazole using recombinant cells that express wild-type serine acetyltransferase (SAT), O-acetylserine sulfhydrylase-A (OASS-A), acetate kinase (AK), and phosphotransacetylase (PTA). Under the optimized condition, β-PA was produced at 140 mM from 200 mM L-Ser and 200 mM pyrazole. On the other hand, in Method B, O-acetyl-L-serine (OAS) was secreted into the broth, using the cells that express SATΔC20 (truncated SAT), OASS-A, AK, and PTA. Under optimized conditions OAS accumulated in the broth at levels of around 100 mM. The secreted OAS was efficiently converted to β-PA at levels of around 90 mM from 105 mM OAS using free OASS-A. In both Methods A and B, the addition of glucose was essential for the efficient production of β-PA and OAS, respectively.

DOI： 10.11491/apcche.2004.0.815.0

Effects of water activity and lipid addition on secondary structure of zein in powder systems 査読

Y Mizutani, Y Matsumura, K Imamura, K Nakanishi, T Mori

JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 51 ( 1 ) 229 - 235 2003年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

The effects of water activity (A(w)) and lipid addition on the secondary structure of powdery zein were investigated using Fourier transform infrared spectroscopy. Two fatty acid esters, i.e., the linolenic and eicosapentaenoic acid ethyl esters (LAE and EPE), were mixed with the zein powder. The powders were stored in the "dry" state (with silica gel) and the "humid" state (A(w) = 0.9). The powdery zein without the lipids was shown to have a high content of the intermolecular hydrogen-bonded beta-sheet in the "dry" state, indicating the presence of protein aggregates. An increase in AW induced a decrease in this beta-sheet, concomitant with increases in the alpha-helix and beta-turn structures. The addition of LAE caused decreases in the alpha-helix and intermolecular hydrogen-bonded beta-sheet of zein when the powder was stored in the "humid" state, suggesting the strong interaction of LAE and zein molecules. However, LAE did not affect the secondary structure of zein in the "dry" state. The addition of EPE hardly influenced the secondary structure of zein, irrespective of A(w). These results are discussed in relation to the antioxidative activity of zein in the powder system, which had studied previously.

DOI： 10.1021/jf0205007

ステンレス表面上の耐熱性アミノペプチダーゼの付着特性と活性発現

長安武司, 山越憲吾, 吉岡千里, 松本訓智, 大西宏輔, 今村維克, 崎山高明, 中西一弘

化学工学会研究発表講演要旨集 2003 682 - 682 2003年

温度走査FTIRによる各種糖類アモルファスマトリクスにおける相互作用の解析

今村維克, 坂浦啓介, 福島厚志, 大山健一, 谷加寿子, 崎山高明, 中西一弘

化学工学会研究発表講演要旨集 2003 688 - 688 2003年

膜面液体培養法(MSLC)と振盪フラスコ培養(SFC)を用いたα-glucosidase生産性の差についての考察

森田正和, 今村維克, 崎山高明, 中西一弘

化学工学会研究発表講演要旨集 2003 681 - 681 2003年

天然由来の高分子電解質を素材とした複合ゲルの調製とその膨潤特性

崎山高明, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2003 995 - 995 2003年

Isolation of a Novel Acylase from Streptomyces mobaraensis for Synthesis of Useful Amide Compounds

Zhang Demin, Koreishi Mayuko, Imamura Koreyoshi, Sakiyama Takaharu, NAKANISHI Kazuhiro

化学工学会研究発表講演要旨集 2003 136 - 136 2003年

Regulation of the Excretion of O-Acetyl-L-serine from Recombinant Escherichia coli Cells and Its Application to Synthesis of L-Cysteine and Non-protein Amino Acids

ZHAO Chunhui, OHNO Katsuhiro, SOGOH Kohji, IMAMURA Koreyoshi, SAKIYAMA Takaharu, NAKANISHI Kazuhiro

化学工学会研究発表講演要旨集 2003 685 - 685 2003年

Enzymatic synthesis of N-acyl-L-amino acids in a glycerol-water system using acylase I from pig kidney 査読

E Wada, M Handa, K Imamura, T Sakiyama, S Adachi, R Matsuno, K Nakanishi

JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY 79 ( 1 ) 41 - 46 2002年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER OIL CHEMISTS SOC A O C S PRESS

N-Medium- and long-chain acyl-L-amino acids were enzymatically synthesized from the corresponding L-amino acids and fatty acids using a reverse hydrolysis. Enzymes that are suitable for the synthetic reaction of N-acyl-L-amino acids were screened on the basis of hydrolytic activity toward N-lauroyl-L-glutamic acid as an indicator. Acylase I from pig kidney (EC 3.5.1.14) showed the highest N-acyl-L-amino acid hydrolytic activity among 57 commercially available enzymes tested. Acylase I effectively catalyzed the synthesis of N-lauroyl-L-amino acids except for N-lauroyl-L-proline and N-lauroyl-L-tyrosine in a glycerol-water system. Under the optimized reaction conditions, N-lauroyl-L-arginine and N-lauroyl-L-glutamic acid were obtained in conversions of 82 and 44%, respectively. The equilibrium constants calculated from the conversion obtained were 5.6, 15.4, 18.0, and 39.4 for the syntheses of N-lauroyl-L-glutamic acid, N.-lauroyl-L-lysine, N-lauroyl-L-glutamine, and N-lauroyl-L-methionine, respectively. N-Acyl-L-arginines with myristic acid and palmitic acid as the fatty acid were also synthesized using acylase I.

DOI： 10.1007/s11746-002-0432-7

Enzymatic modification of beta-lactoglobulin with N-fatty-acyl-dipeptide by transglutaminase from Streptomyces mobaraense 査読

E Wada, H Masuda, K Imamura, T Sakiyama, S Adachi, R Matsuno, K Nakanishi

BIOTECHNOLOGY LETTERS 23 ( 17 ) 1367 - 1372 2001年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER

beta -Lactoglobulin was enzymatically acylated with N-lauroyl-L-glutaminyl-glycine and N-lauroyl-L-glutamyl-L-lysine using transglutaminase from Streptomyces mobaraense. The modification of the protein with N-fatty-acyl-dipeptide was confirmed by SDS-PAGE, gel chromatography, HPLC, amino acid analysis, and TOF-MS. The degrees of the protein modification with N-lauroyl-L-glutaminyl-glycine and N-lauroyl-L-glutamyl-L-lysine were estimated to be 2-4 and 1.5 residues per molecule, respectively.

DOI： 10.1023/A:1011699921628

Role of sucrose-LDH hydrogen bond for thermal stabilizing effect of sucrose on freeze-dried LDH 査読

T Suzuki, K Imamura, H Fujimoto, M Okazaki

DRYING TECHNOLOGY 17 ( 7-8 ) 1429 - 1439 1999年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：TAYLOR & FRANCIS INC

Relationship between thermal stabilizing effect of sugar on freeze-dried protein and sugar-protein hydrogen bond is studied. Sucrose and lactate dehydrogenase (LDH) are used as models for sugar and protein. Samples of freeze-dried LDH involved in sucrose of different crystallinity were prepared, and measurement of X-ray diffractometry (XRD) and Fourier-Transform Infrared (FT-IR) spectroscopy was done. It is found that when sucrose is amorphous, the degree of hydrogen bond formation is high and LDH is stabilized; when sucrose is crystalline, hydrogen bond is less formed and LDH is inactivated. These results indicate that the stabilizing effect of sugar is closely related to sugar-protein hydrogen bond. It is also found that there is an optimum sucrose content for the thermal stabilizing effect. This is because amorphous structure of sucrose is stabilized and protected from crystallization by LDH. Thus we can deduce that sugars and proteins work together to keep the activities of proteins.

DOI： 10.1080/07373939908917625

Relation between thermal stabilizing effect of sucrose on LDH and sucrose-LDH hydrogen bond 査読

T Suzuki, K Imamura, H Fujimoto, M Okazaki

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN 31 ( 4 ) 565 - 570 1998年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC CHEMICAL ENG JAPAN

The thermal stabilizing effect of sugar on freeze-dried protein is studied, in particular on the relationship between the thermal stabilizing effect and the degree of sugar-protein hydrogen bond formation. Sucrose and lactate dehydrogenase (LDH) are used as models for sugar and protein. Several freeze-dried samples of LDH involved in sucrose were prepared; they differed in the degree of crystallinity of sucrose, By X-ray diffractometry (XRD) and Fourier transform infrared (FT-IR) spectroscopy, it is found that when sucrose is amorphous in the samples, the degree of hydrogen bond formation is high and LDH is stabilized remarkably. In contrast, when sucrose is crystalline, the degree of hydrogen bond formation is low and LDH is inactivated. These results indicate that the stabilizing effect of sugar is closely related to the sugar-protein hydrogen bond. The influence of sucrose content on the thermal stabilizing effect is also investigated. It is found that there is an optimum sucrose content for the thermal stabilizing effect. This is because, by the presence of LDH, the amorphous structure of sucrose is stabilized and protected from crystallization that causes loss of sucrose-LDH hydrogen bonds. Thus, we can deduce that sugars and proteins work together to maintain protein activities.

DOI： 10.1252/jcej.31.565

Thermal stabilization of freeze-dried enzymes by sugars 査読

T Suzuki, K Imamura, K Yamamoto, T Satoh, M Okazaki

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN 30 ( 4 ) 609 - 613 1997年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC CHEMICAL ENG JAPAN

The thermal stabilization effect of sugars on freeze-dried proteins is studied, particularly the relation between stabilizing effect and the degree of sugar crystallinity. Three kinds of enzymes, alcohol dehydrogenase (ADH), lactate dehydrogenase (LDH), and malate dehydrogenase (MDH), were used as model proteins. Aqueous solutions of enzymes with sugars were freeze-dried and stored in dry air at 65 degrees C. The stabilities of freeze-dried enzymes improve remarkably by addition of trehalose or raffinose. By measurement of X-ray diffractometry, the sugars are found to form fully amorphous matrix in freeze-dried samples. Furthermore, sucrose stabilizes enzymes to a great extent when it is amorphous in samples, though it shows Little stabilizing effect when it is crystalline. These results indicate that the stabilizing effect of sugars closely relates to the amorphous matrix formed by the sugars.

DOI： 10.1252/jcej.30.609

Stabilizing effect on freeze-dried proteins by amorphous matrices of sugars 査読

T Suzuki, K Imamura, K Yamamoto, M Okazaki

DRYING '96, VOL B 1261 - 1266 1996年

A New Method for Measurement of Powder Characteristics Based on Reentrainment Phenomena 査読

Hiroaki Masuda, Shuji Matsusaka, Koreyoshi Imamura

KONA Powder and Particle Journal 12 133 - 143 1994年

記述言語：英語掲載種別：研究論文（学術雑誌）

A new method has been developed to measure and evaluate the operational powder characteristics for fine particle processing based on the reentrainment phenomena. Experiments on particle reentrainment were carried out using an accelerated air flow for 21 different test powders. Both the reentrainment fluxes, which were measured by an electrostatic method, and the average air velocities were automatically sampled by a computer. The sampled data were processed to obtain the reentrainment profiles as a function of the average air velocity. The cumulative reentrainment efficiencies were also obtained and represented as a function of the wall shear stress. It was found that fine particles having tendencies to form large aggregates were reentrained mainly in the early stage of the measurement when the flow velocity was as low as 5 m·s−1. Also, the mass ratio of the reentrained large aggregates to the total particles was used to obtain information on the particle-particle (cohesion) or particle-wall interactions (adhesion). On the other hand, the cumulative reentrainment efficiency-curves must be applied to determine the operational conditions controlling the amount of adhered particles in various aerosol processes. © 1994, Hosokawa Powder Technology Foundation. All rights reserved.

DOI： 10.14356/kona.1994021

飛散現象を利用した粉体特性の測定と評価

増田弘昭, 松坂修二, 今村維克

粉体工学会誌 29 ( 12 ) 897 - 905 1992年

記述言語：日本語出版者・発行元：The Society of Powder Technology, Japan

A new method has been developed to measure and evaluate the operational powder characteristics for fine particle processing based on the reentrainment phenomena. Experiments on particle reentrainment were carried out by use of an accelerated air flow for 21 different test powders. Both the reentrainment fluxes, which were measured by an electrostatic method, and the average air velocities were automatically sampled in a computer. The sampled data were processed to give the reentrainment profiles as a function of the average air velocity. The cumulative reentrainment efficiencies were also obtained and represented by a function of the wall shear stress.<br>It was found that fine particles having tendencies to form large aggregates were reentrained mainly in the early stage of the measurement where the flow velocity was as low as 5m·s^-1. Also, the mass ratio of the reentrained large aggregates to the total particles was well applied to obtain the information on the particle-particle or particle-wall interactions. On the other hand, the cumulative reentrainment efficiency-curves would be applied to determine the operational conditions controlling the amount of adhered particles in various aerosol processes.

DOI： 10.4164/sptj.29.897

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