研究者詳細 - 今中　洋行

論文 - 今中　洋行

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Avoidance of crystallization of hydrophobic drugs in an amorphous solid dispersion during spray-drying and storage

Rina Yamamoto, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

Drying Technology 42 ( 13 ) 2022 - 2031 2024年9月

Flavor retention characteristics of amorphous solid dispersion of flavors, prepared by vacuum-foam- and spray-drying under different conditions

Yuna Nitta, Haruna Sato, Rina Yamamoto, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

Drying Technology 1 - 11 2023年11月

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

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

JOURNAL OF FOOD ENGINEERING 349 2023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：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.

DOI： 10.1016/j.jfoodeng.2023.111483

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

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

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

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

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.

DOI： 10.1016/j.colsurfa.2022.128392

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

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

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

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

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS 627 2021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

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.

DOI： 10.1016/j.colsurfa.2021.127174

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

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

Crystallization characteristics of amorphous trehalose dried from alcohol

Takanari Sekitoh, Takashi Okamoto, Akiho Fujioka, Tomohiko Yoshioka, Shinji Terui, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

Journal of Food Engineering 292 110325 - 110325 2021年3月

Spontaneous foaming during vacuum drying of polyvinylpyrrolidone- and sugar-alcohol mixtures and enhancement of water-dissolution of water insoluble drug

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

Drying Technology 1 - 11 2020年9月

The Use of a Combination of a Sugar and Surfactant to Stabilize Au Nanoparticle Dispersion against Aggregation during Freeze-Drying

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

Langmuir 36 ( 24 ) 6698 - 6705 2020年6月

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

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

Drying Technology 39 ( 14 ) 1 - 10 2020年4月

Immobilization of surface non-affinitive protein onto a metal surface by an external electric field

Olivier Tramis, Ryosuke Iizuka, Hajime Nakao, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

Journal of Bioscience and Bioengineering 129 ( 3 ) 348 - 353 2020年3月

Picoliter enzyme reactor on a nanofluidic device exceeding the bulk reaction rate

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

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.

Physical Stability of an Amorphous Sugar Matrix Dried From Methanol as an Amorphous Solid Dispersion Carrier and the Influence of Heat Treatment 査読

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

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

Colloids and Surfaces B: Biointerfaces 166 262 - 268 2018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：Elsevier B.V.

The effect of the properties of a protein on its adsorption to a metal surface in the presence of external electric potential was investigated. Protein adsorption processes at different surface potentials were measured for fifteen types of proteins using an in-situ ellipsometry. The tested proteins were classified into three groups, based on the amount of protein that was adsorbed as a function of the surface potential: In First group of proteins, an increasing trend for the amount adsorbed with a more positive surface potential was found
The amount adsorbed of α-chymotrypsinogen A and ribonuclease A (Second group) were roughly constant and independent of the applied surface electric potentials
In Third group, the amount adsorbed decreased with increasing surface potential. This protein classification was correlated with the isoelectric points of the proteins (First group: ≤9.3
Second group: 9.3–10
Third group: &gt
10). Increasing the pH positively and negatively shifted the surface potentials, allowing ß-lactoglobulin (First group) and lysozyme (Third) to become adsorbed, respectively. The surface potential range for protein adsorption was also markedly shifted depending on the metal substrate type. These findings were interpreted based on the electrostatic interactions among the protein, surface hydroxyl groups, and the applied external electric field.

DOI： 10.1016/j.colsurfb.2018.03.035

Controlling the drying process in vacuum foam drying under low vacuum conditions by inducing foaming by needle stimulation of the solution 査読

Fumihiro Hidaka, Tomo Satoh, Akiho Fujioka, Koji Takeda, Hiroyuki Imanaka, Naoyuki Ishida, Koreyoshi Imamura

Drying Technology 36 2018年

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

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

COLLOIDS AND SURFACES B-BIOINTERFACES 159 118 - 124 2017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

Enzymatic cleaning is a potentially useful method for removing proteinaceous fouling from solid surfaces under mild conditions. Herein, the influence of an external electric field on the enzymatic cleaning of a metal surface fouled with a protein was investigated. The model fouling protein (BSA; lysozyme) was prepared on a stainless steel (St) surface, and the resulting surface subjected to enzymatic cleaning with an electric potential being applied to the St plate. Trypsin, alpha-chymotrypsin, and thermolysin were used as model proteases. The amounts of protein remaining on the plate before and during the cleaning process were measured by means of a reflection absorption technique using Fourier transform infrared spectroscopy. In the case for BSA fouling, the cleaning efficiency of the protease tended to increase at more negative applied potentials. Whereas, there was an optimum applied potential for removing the lysozyme fouling. Atomic force microscopy analyses indicated that applying an adequate range of electric potential enhanced the enzymatic removal of protein fouling inside scratches on the St plate surface. These findings suggest the existence of two modes of electrostatic interactions for the external electric field, one with protease molecules and the other with digested fragments of the fouling protein. (C) 2017 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.colsurfb.2017.07.074

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

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.

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

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.

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 H, Nakama Y, Tanaka H, Imanaka H, Ishida N, Imamura K

Colloids and surfaces. B, Biointerfaces 147 9 - 16 2016年11月

Molecular design of proteinaceous cushion for sensitive biomolecular interaction detection system 査読

Imanaka Hiroyuki, Dare Koki, Imamura Koreyoshi

NEW BIOTECHNOLOGY 33 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

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.

DOI： 10.1016/j.foodchem.2015.11.097

Nanostructures of 3-aminopropyltriethoxysilane created on flat substrate by combining colloid lithography and vapor deposition 査読

Naoyuki Ishida, Ryohei Nishihara, Hiroyuki Imanaka, Koreyoshi Imamura

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS 495 39 - 45 2016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 creation of patterned structures with micro/nano-scale lengths on flat surfaces has recently been emerged as an important technique in various fields. In this report, we present a simple method to create nanopatterns of 3-aminopropyltriethoxysilane (APS) on glass substrates by the combination of colloid lithography and vapor deposition. When deposition was conducted at room temperature under natural humidity, an array of nanorings was formed on the substrate by the condensation of APS vapor on the water bridges remaining under the particles. By varying only the deposition temperature, the structure of the ordered arrays could easily be transformed: nanorings were converted to honeycomb and dot like structures by increasing temperature. This transformation proposedly occurred by the condensation and polymerization of APS vapor through the deformed particles of the colloidal monolayer. We also fabricated a patterned polymer brush array and a pore array using the obtained APS nanopattern as a template. (C) 2016 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.colsurfa.2016.01.047

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 an, Koreyoshi Imamura

Biotechnology Progress 32 ( 2 ) 527 - 534 2016年3月

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

Soga Yuhei, Imanaka Hiroyuki, Imamura Koreyoshi, Ishida Naoyuki

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

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

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.

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

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.

DOI： 10.1016/j.foodres.2015.02.003

Polymorphobacter multimanifer gen. nov., sp nova, a polymorphic bacterium isolated from antarctic white rock 査読

Wakao Fukuda, Yohzo Chino, Shigeo Araki, Yuka Kondo, Hiroyuki Imanaka, Tamotsu Kanai, Haruyuki Atomi, Tadayuki Imanaka

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY 64 ( 6 ) 2034 - 2040 2014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：SOC GENERAL MICROBIOLOGY

A Gram-stain-negative, non-spore-forming, aerobic, oligotrophic bacterium (strain 262-7(T)) was isolated from a crack of white rock collected in the Skallen region of Antarctica. Strain 262-7(T) grew at temperatures between -4 and 30 degrees C, with optimal growth at 25 degrees C. The pH range for growth was between pH 6.0 and 9.0, with optimal growth at approximately pH 7.0. The NaCl concentration range allowing growth was between 0.0 and 1.0%, with an optimum of 0.5%. Strain 262-7(T) showed an unprecedented range of morphological diversity in response to growth conditions. Cells grown in liquid medium were circular or ovoid with smooth surfaces in the lag phase. In the exponential phase, ovoid cells With short projections were observed. Cells in the stationary phase possessed long tentacle-like projections intertwined intricately. By contrast, cells grown on agar plate medium or in liquid media containing organic compounds at low concentration exhibited short- and long-rod-shaped morphology. These projections and morphological variations clearly differ from those of previously described bacteria. Ubiquinone 10 was the major respiratory quinone. The major fatty acids were C-17:1 omega 6c (28.2%), C-16:1 omega 7c (22.6%), C-18:1 omega 7c (12.9%) and C(15:0)2-OH (12.3%). The G+C content of genomic DNA was 68.0 mol%. Carotenoids were detected from the cells. Comparative analyses of 16S rRNA gene sequences indicated that strain 262-7(T) belongs to the family Sphingomonadaceae, and that 262-7(T) should be distinguished from known genera in the family Sphingomonadaceae. According to the phylogenetic position, physiological characteristics and unique morphology variations, strain 262-7(T) should be classified as a representative of a novel genus of the family Sphingomonadaceae. Here, a novel genus and species with the name Polymorphobacter multimanifer gen. nov., sp. nov. is proposed (type strain 262-7(T)=JCM 18140(T)=ATCC BAA-2413(T)). The novel species was named after its morphological diversity and formation of unique projections.

DOI： 10.1099/ijs.0.050005-0

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

Effect of Surface Hydrophobicity on Short-Range Hydrophobic Attraction between Silanated Silica Surfaces 査読

Yuuhei Soga, Hiroyuki Imanaka, Koreyoshi Imamura, Naoyuki Ishida

Advanced Powder Technology 51 ( 5 ) 343 - 348 2014年

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

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

The Discoidin Domain of Bacillus circulans β-Galactosidase Plays an Essential Role in Repressing Galactooligosaccharide Production 査読

Jingyuan Song, Hiroyuki Imanaka, Koreyoshi Imamura, Masashi Minoda, Shotaro Yamaguchi an, Kazuhiro Nakanishi

Bioscience Biotechnology and Biochemistry 77 ( 1 ) 73 - 79 2013年1月

Cloning and Expression of a β-Galactosidase Gene of Bacillus circulans 査読

Jingyuan Song, Hiroyuki Imanaka, Koreyoshi Imamura, Masashi Minoda, Toru Katase, Yukiko Hoshi, Shotaro Yamaguchi, Kazuhiro Nakanishi

Bioscience Biotechnology and Biochemistry 75 ( 6 ) 1194 - 1197 2011年6月

Causes of the Production of Multiple Forms of β-Galactosidase by Bacillus circulans 査読

Jingyuan Song, Kiriko Abe, Hiroyuki Imanaka, Koreyoshi Imamura, Masashi Minoda, Shotaro, Yamaguchi, Kazuhiro Nakanishi

Bioscience Biotechnology and Biochemistry 75 ( 2 ) 268 - 278 2011年2月

An archaeal 2-deoxyribose 4-phosphate aldolase that exhibits closer homology to bacteria rather than archaea 査読

Naeem Rashid, Hiroyuki Imanaka, Tadayuki Imanaka

Journal of Chemical Society of Pakistan 30 ( 5 ) 740 - 749 2011年

Development of a highly efficient indigo dyeing method using indican with an immobilized β-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

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

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

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

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

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

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

Efficient Ethanol Production from Wheat Bran by Enzymatic Saccharification Using Commercially Available Enzyme Products and Fermentation Using Bakers' Yeast 査読

Mayuko Koreishi, Hiroyuki Imanaka, Koreyoshi Imamura, Masahiro Kariyama, Kazuhiro Nakanishi

Seibutsu-kogaku Kaishi 87 ( 5 ) 216 - 223 2009年

記述言語：日本語出版者・発行元：日本生物工学会

小麦フスマを原料として用い,市販酵素製剤による糖化反応と酵母によるエタノール発酵を併用した効率的エタノール生産方法の構築のために必要なバイオマスの前処理条件および糖化のための酵素の組み合わせなどの検討を行った.糖化反応条件としては,小麦フスマを140℃で保持時間0hの条件下で水熱処理を行い,反応温度45℃でMeiselaseおよびNovozyme^[○!R]188の2種類の酵素製剤を用いて糖化することが,グルコース生成に対して最も効果的であることがわかった.3.3%(w/v)の水熱処理小麦フスマから理論値の90%に相当するグルコースが生成した.しかし,33%(w/v)の水熱処理小麦フスマを用いた場合には,理論値の72%のグルコースしか生成しなかった.この理由として,反応生成物であるグルコースのβ-グルコシダーゼに対する阻害の影響が考えられた.しかし,酵素糖化を45℃で24時間行った後に,酵母を添加し30℃でエタノール発酵を行うと,糖化反応とグルコース消費が併行して起こるために阻害効果が緩和され,その結果,理論値の88%に相当する約5.2%(w/v)のエタノールが生成した.

その他リンク： http://dl.ndl.go.jp/info:ndljp/pid/10516714

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Phosphoenolpyruvate synthase plays an essential role for glycolysis in the modified Embden-Meyerhof pathway in Thermococcus kodakarensis 査読

Hiroyuki Imanaka, Atsushi Yamatsu, Toshiaki Fukui, Haruyuki Atomi, Tadayuki Imanaka

MOLECULAR MICROBIOLOGY 61 ( 4 ) 898 - 909 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：BLACKWELL PUBLISHING

We have carried out a genetic analysis on pyruvate kinase (Pyk(Tk)) and phosphoenolpyruvate synthase (Pps(tk)) in the hyperthermophilic archaeon, Thermococcus kodakarensis. In principle, both enzymes can catalyse the final step of the modified Embden-Meyerhof (EM) pathway found in Thermococcales, the conversion of phosphoenolpyruvate (PEP) to pyruvate, with the former utilizing ADP, while the latter is dependent on AMP and phosphate. Enzyme activities and transcript levels of both Pyk(Tk) and Pps(Tk) increased in T. kodakarensis under glycolytic conditions when compared with cells grown on pyruvate or amino acids. Using KW128, a tryptophan auxotrophic mutant with a trpE gene disruption, as a host strain, we obtained mutant strains with single gene disruptions in either the pyk(Tk) (Delta pyk strain) or pps(Tk) (Delta pps strain) gene. Specific growth rates and cell yields were examined in various media and compared with the host KW128 strain. The results indicated that both enzymes participated in pyruvate metabolism, but were not essential. In the presence of maltooligosaccharides, the Delta pyk strain displayed a 15% decrease in growth rate compared with the host strain, indicating that Pyk(Tk) does participate in glycolysis. However an even more dramatic effect was observed in the Delta pps strain in that the strain could not grow at all on maltooligosaccharides. The results clearly indicate that, in contrast to the conventional EM pathway dependent on pyruvate kinase, PEP synthase is the essential enzyme for the glycolytic conversion of PEP to pyruvate in T. kodakarensis. The physiological roles of the two enzymes under various growth conditions are discussed.

DOI： 10.1111/j.1365-2958.2006.05287.x

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

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

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

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

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

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

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

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

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

Continuous hydrogen production by the hyperthermophilic archaeon, Thermococcus kodakaraensis KOD1 査読

T Kanai, H Imanaka, A Nakajima, K Uwamori, Y Omori, T Fukui, H Atomi, T Imanaka

JOURNAL OF BIOTECHNOLOGY 116 ( 3 ) 271 - 282 2005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

The hydrogen (H-2) production potential of the hyperthermophilic archaeon, Thermococcus kodakaraensis KOD1 was evaluated at 85 degreesC. In batch cultivation using a complex medium supplemented with elemental sulfur (S-0), evolution of H2S and CO2 was observed in the gas phase. When So was omitted and pyruvate or starch was added in the medium, the cells produced H-2 at high levels instead of H2S. As the level of H-2 appeared to correlate with the specific growth rate, analysis in continuous cultures was performed to develop a continuous H-2 production system. In a steady-state condition at a dilution rate of 0.2 h(-1), a continuous H-2 production rate (per gram dry weight, gdw) of 24.9 and 14.0 mmol gdw(-1) h(-1) was observed in media supplemented with pyruvate and starch, respectively. In both cultivations, a high accumulation of acetate and alanine was found as metabolites. When the dilution rates were elevated in the medium with pyruvate, steady-state growth was observed up to 0.8 h(-1), and a maximum H-2 production rate of 59.6 mmol gdw(-1) h(-1) was obtained. Based on the experimental results along with data of the entire genome sequence, the metabolic pathway of the strain relating to starch and pyruvate degradation is discussed. (C) 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jbiotec.2004.11.002

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

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

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

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

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

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

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

Genetic evidence identifying the true gluconeogenic fructose-1,6-bisphosphatase in Thermococcus kodakaraensis and other hyerthermophiles. 査読

T Sato, H Imanaka, N Rashid, T Fukui, H Atomi, T Imanaka

JOURNAL OF BACTERIOLOGY 186 ( 17 ) 5799 - 5807 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：AMER SOC MICROBIOLOGY

Fructose-1,6-bisphosphatase (FBPase) is one of the key enzymes in gluconeogenesis. Although FBPase activity has been detected in several hyperthermophiles, no orthologs corresponding, to the classical FBPases from bacteria and eukaryotes have been identified in their genomes. An inositol monophosphatase (IMPase) from Methanococcus jannaschii which displayed both FBPase and IMPase activities and a structurally novel FBPase (Fbp(Tk)) from the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1 have been proposed as the "missing" FBPase. For this study, using T. kodakaraensis, we took a genetic approach to elucidate which candidate is the major gluconeogenic enzyme in vivo. The IMPase/FBPase ortholog in T. kodakaraensis, Imp(Tk), was confirmed to possess high FBPase activity along with IMPase activity, as in the case of other orthologs. We therefore constructed Deltafbp and Deltaimp strains by applying a gene disruption system recently developed for T. kodakaraensis and investigated their phenotypes. The Deltafbp strain could not grow under gluconeogenic conditions while glycolytic growth was unimpaired, and the disruption resulted in the complete abolishment of intracellular FBPase activity. Evidently, fbp(Tk) is an indispensable gene for gluconeolgenesis and is responsible for almost all intracellular FBPase activity. In contrast, the endogenous imp(Tk) gene could not complement the defect of the fbp deletion, and its disruption did not lead to any detectable phenotypic changes under the conditions examined. These facts indicated that imp(Tk) is irrelevant to gluconeogenesis, despite the high FBPase activity of its protein product, probably due to insufficient transcription. Our results provide strong evidence that the true FBPase for gluconeogenesis in T. kodakaraensis is the FbpTk ortholog, not the IMPase/FBPase ortholog.

DOI： 10.1128/JB.186.17.5799-5807.2004

Presence of a novel phosphopentomutase and a 2-deoxyribose 5-phosphate aldolase reveals a metabolic link between pentoses and central carbon metabolism in the hyperthermophilic archaeon Thermococcus kodakaraensis 査読

N Rashid, H Imanaka, T Fukui, H Atomi, T Imanaka

JOURNAL OF BACTERIOLOGY 186 ( 13 ) 4185 - 4191 2004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：AMER SOC MICROBIOLOGY

Numerous bacteria and mammalian cells harbor two enzymes, phosphopentomutase (PPM) and 2-deoxyribose 5-phosphate aldolase (DERA), involved in the interconversion between nucleosides and central carbon metabolism. In this study, we have examined the presence of this metabolic link in the hyperthermophilic archaeon, Thermococcus kodakaraensis KOD1. A search of the genome sequence of this strain revealed the presence of a closely related orthologue (TK2104) of bacterial DERA genes while no orthologue related to previously characterized PPM genes could be detected. Expression, purification, and characterization of the TK2104 protein product revealed that this gene actually encoded a DERA, catalyzing the reaction through a class I aldolase mechanism. As PPM activity was detected in T. kodakaraensis cells, we partially purified the protein to examine its N-terminal amino acid sequence. The sequence corresponded to a gene (TK1777) similar to phosphomannomutases within COG1109 but not COG1015, which includes all previously identified PPMs. Heterologous gene expression of TK1777 and characterization of the purified recombinant protein clearly revealed that the gene indeed encoded a PPM. Both enzyme activities could be observed in T. kodakaraensis cells under glycolytic and gluconeogenic growth conditions, whereas the addition of ribose, 2-deoxyribose, and 2'-deoxynucleosides in the medium did not lead to a significant induction of these activities. Our results clearly indicate the presence of a metabolic link between pentoses and central carbon metabolism in T. kodakaraensis, providing an alternative route for pentose biosynthesis through the functions of DERA and a structurally novel PPM.

DOI： 10.1128/JB.186.13.4185-4191.2004

Gene cloning and characterization of fructose-1,6-bisphosphate aldolase from the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1 査読

H Imanaka, T Fukui, H Atomi, T Imanaka

JOURNAL OF BIOSCIENCE AND BIOENGINEERING 94 ( 3 ) 237 - 243 2002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

The fructose-1,6-bisphosphate (FBP) aldolase gene from the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1 was cloned. The gene encoding FBP aldolase (Tk-fba) was expressed in Escherichia coli and the purified recombinant protein was characterized at high temperature. Tk-Fba is a homodecamer with a subunit molecular mass of 31,283 Da. The amino acid sequence, decameric conformation, formation of a Schiff-base intermediate, and stimulation (286%) of FBP cleavage activity by citrate suggested that Tk-Fba belonged to Class IA, a subtype of the classical Class I aldolases. The specific activity for the FBP cleavage reaction was 18.9 U/mg, which was much higher than those of other Class IA type FBP aldolases. Tk-Fba was extremely thermostable since the optimum temperature seemed to be above 100degreesC. The optimum pH for Tk-Fba was determined to be 5.0 in the absence of citrate, while it shifted to around 7.0 in the presence of citrate. Tk-Fba accepted FBP and fructose-1-phosphate as substrates and K-m values were determined to be 0.063 mM and 4.37 mM, respectively. In addition to citrate, phosphoenolpyruvate and pyrophosphate were also found to be potent activators of Tk-Fba, enhancing activities up to 346% and 201%, respectively. Erythrose-4-phosphate acted as an inhibitor and caused a decrease in the activity to 49%. Tk-Fba also catalyzed the condensation reaction with a similar activity level (14.9 U/mg) to that for FBP cleavage. However, none of the above compounds seemed to have a significant effect on the condensation reaction by Tk-Fba. These results suggest a regulatory function of Tk-Fba toward the catabolic direction of sugar metabolism in T. kodakaraensis KOD1.

DOI： 10.1263/jbb.94.237

A novel candidate for the true fructose-1,6-bisphosphatase in Archaea 査読

N Rashid, H Imanaka, T Kanai, T Fukui, H Atomi, T Imanaka

JOURNAL OF BIOLOGICAL CHEMISTRY 277 ( 34 ) 30649 - 30655 2002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 SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC

Fructose-1,6-bisphosphatase (FBPase) is one of the key enzymes of the gluconeogenic pathway. Although enzyme activity had been detected in Archaea, the corresponding gene had not been identified until a presumable inositol monophosphatase gene from Methanococcus jannaschii was found to encode a protein with both inositol monophosphatase and FBPase activities. Here we display that a gene from the hyperthermophilic archaeon, Thermococcus kodakaraensis KOD1, which does not correspond to the inositol monophosphatase gene from M. jannaschii, displays high FBPase activity. The FBPase from strain KOD1 was partially purified, its N-terminal amino acid sequence was determined, and the gene (Tk-fbp) was cloned. Tk-fbp encoded a protein of 375 amino acid residues with a molecular mass of 41,658 Da. The recombinant Tk-Fbp was purified and characterized. Tk-Fbp catalyzed the conversion of fructose 1,6-bisphosphate to fructose 6-phosphate following Michaelis-Menten kinetics with a K-m value of 100 mum toward fructose 1,6-bisphosphate, and a k(cat) value of 17 s(-1) subunit(-1) at 95degreesC. Unlike the inositol monophosphatase from M. jannaschii, Tk-Fbp displayed strict substrate specificity for fructose 1,6-bisphosphate. Activity was enhanced by Mg2+ and dithioerythritol, and was slightly inhibited by fructose 2,6-bisphosphate. AMP did not inhibit the enzyme activity. We examined whether expression of Tk-fbp was regulated at the transcription level. High levels of Tk-fbp transcripts were detected in cells grown on pyruvate or amino acids, whereas no transcription was detected when starch was present in the medium. Orthologue genes corresponding to Tk-fbp with high similarity are present in all the complete genome sequences of thermophilic Archaea, including M. jannaschii, Pyrococcus furiosus, Sulfolobus solfataricus, and Archaeoglobus fulgidus, but are yet to be assigned any function. Taking into account the high FBPase activity of the protein, the strict substrate specificity, and its sugar-repressed gene expression, we propose that Tk-Fbp may represent the bona fide FBPase in Archaea.

DOI： 10.1074/jbc.M202868200

Removal of aromatic compounds in gas by electron attachment 査読

H Tamon, H Imanaka, N Sano, M Okazaki, W Tanthapanichakoon

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 37 ( 7 ) 2770 - 2774 1998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：AMER CHEMICAL SOC

A corona-discharge reactor was applied to remove benzene and p-dichlorobenzene from nitrogen and a nitrogen-oxygen mixture. Although benzene was not effectively removed from nitrogen by electron attachment, the removal efficiency was improved greatly by mixing oxygen. On the other hand, the high removal efficiencies of p-dichlorobenzene were obtained in nitrogen or a nitrogen-oxygen mixture. The removal mechanism was studied based on the contribution of the ozone reaction and the analysis of the deposit on the anode of the reactor. As a result, the ozone reaction does not contribute to the removals. An FT-IR measurement and thermogravimetry suggest that benzene or p-dichlorobenzene is decomposed by dissociative electron attachment and deposits as polycyclic aromatic compounds of a high boiling point on the anode surface.

DOI： 10.1021/ie980071v

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