Updated on 2024/02/07

写真a

 
IMANAKA Hiroyuki
 
Organization
Faculty of Environmental, Life, Natural Science and Technology Assistant Professor
Position
Assistant Professor
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Degree

  • 博士(工学) ( 京都大学 )

Research Interests

  • genetic engineering

  • immobilization

  • peptide

  • protein

  • hyperthemophile

  • 遺伝子工学

  • intermolecular interaction

  • 超好熱菌

  • 分子間相互作用

  • 固定化

  • ペプチド

  • タンパク質

  • protein engineering

  • タンパク質工学

Research Areas

  • Life Science / Applied biochemistry

  • Nanotechnology/Materials / Composite materials and interfaces

  • Life Science / Molecular biology

  • Life Science / Food sciences

  • Nanotechnology/Materials / Bio chemistry

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Biofunction and bioprocess engineering

  • Nanotechnology/Materials / Nanobioscience

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Education

  • Kyoto University   大学院工学研究科   合成・生物化学専攻

    - 2003.3

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  • Kyoto University   大学院工学研究科   化学工学専攻

    - 1999.3

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  • Kyoto University   工学部   工業化学科

    - 1997.3

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Professional Memberships

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Committee Memberships

  • 日本生物工学会 若手会   会長  

    2017.9 - 2019.9   

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  • 日本農芸化学会   Frontiersシンポジウム実行委員長  

    2014.4 - 2015.3   

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  • 日本農芸化学会中四国支部   参与  

    2013.4   

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  • Young Asian Biological Engineers' Community (YABEC)   日本事務局メンバー  

    2011.6   

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  • 岡山地区化学工学懇話会   幹事  

    2011.4   

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  • 日本生物工学会西日本支部   幹事(会計)  

    2011.4 - 2013.4   

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  • 日本生物工学会   若手研究者の集いセミナー実行委員長  

    2009.8 - 2010.7   

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Papers

  • 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   2023.11

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    Publishing type:Research paper (scientific journal)   Publisher:Informa UK Limited  

    DOI: 10.1080/07373937.2023.2285413

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  • 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   2023.7

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher: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

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

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

    Analytical Chemistry   2022.10

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    Publishing type:Research paper (scientific journal)   Publisher:American Chemical Society (ACS)  

    DOI: 10.1021/acs.analchem.2c02878

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  • 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   2022.4

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    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

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  • 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   2022.1

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    Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.colsurfa.2021.127744

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  • 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   2021.10

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher: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

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  • 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   2021.10

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    Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.apt.2021.08.002

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

    Hikaru Kawaguchi, Hiroyuki Imanaka, Koreyoshi Imamura, Naoyuki Ishida

    Colloids and Surfaces A: Physicochemical and Engineering Aspects   627   127137 - 127137   2021.10

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Elsevier {BV}  

    DOI: 10.1016/j.colsurfa.2021.127137

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  • 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   2021.3

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    Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.jfoodeng.2020.110325

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  • 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   2020.9

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    Publishing type:Research paper (scientific journal)   Publisher:Informa UK Limited  

    DOI: 10.1080/07373937.2020.1822863

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  • 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   2020.6

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    Publishing type:Research paper (scientific journal)   Publisher:American Chemical Society (ACS)  

    DOI: 10.1021/acs.langmuir.0c00695

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  • 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   2020.4

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    Publishing type:Research paper (scientific journal)   Publisher:Informa UK Limited  

    DOI: 10.1080/07373937.2020.1752711

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  • 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   2020.3

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    Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.jbiosc.2019.09.008

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  • 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

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    Publishing type:Research paper (scientific journal)   Publisher:Royal Society of Chemistry (RSC)  

    <p>A picoliter enzyme reactor using a trypsin immobilized nanochannel realized 25 times faster reaction than the bulk reaction.</p>

    DOI: 10.1039/d0an00998a

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

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

    Journal of Pharmaceutical Sciences   108 ( 6 )   2056 - 2062   2019.6

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE INC  

    An amorphous sugar matrix, after drying from an organic solvent, was investigated for use as a method for dispersing hydrophobic drugs (solid dispersion). However, the amorphous sugar, originally contained in the organic solvent, had a significantly low glass transition temperature (T-g), thus rendering it physically unstable. In this study, we examined the physicochemical properties of a sugar in a dried matrix and in an organic solvent, using alpha-maltose and methanol as a representative sugar and organic solvent. The apparent molar volume of alpha-maltose was similar to 30% smaller in methanol than in water. The methanol-originated amorphous alpha-maltose exhibited a much greater degree of hydrogen bonding than the water-originated one. Considering these findings, we conclude that the alpha-maltose maintained its compact conformation in the dried state and consequently caused the markedly low T-g. Second, it was found that heating under appropriate conditions resulted in an increase in the T-g of the methanol-originated amorphous alpha-maltose as well as a decrease in the level of hydrogen bonding. The aqueous dissolution of 2 model hydrophobic drugs (indomethacin and ibuprofen) from the solid dispersion was also improved as the result of the heat treatment, whereas, to the contrary, the dissolution of another model drug (curcumin) was lowered. (c) 2019 American Pharmacists Association (R). Published by Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.xphs.2019.01.008

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

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

    Colloids and Surfaces B: Biointerfaces   166   262 - 268   2018.6

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher: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

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

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

    Drying Technology   36   2018

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

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

    COLLOIDS AND SURFACES B-BIOINTERFACES   159   118 - 124   2017.11

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher: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

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

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

    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY   81 ( 4 )   687 - 697   2017.4

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher: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

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

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

    MOLECULAR PHARMACEUTICS   14 ( 3 )   791 - 798   2017.3

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher: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

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  • Adsorption of lysozyme on base metal surfaces in the presence of an external electric potential. Reviewed

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

    Colloids and surfaces. B, Biointerfaces   147   9 - 16   2016.11

  • Molecular design of proteinaceous cushion for sensitive biomolecular interaction detection system Reviewed

    Imanaka Hiroyuki, Dare Koki, Imamura Koreyoshi

    NEW BIOTECHNOLOGY   33   S72   2016.7

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

    Naoyuki Ishida, Ryohei Nishihara, Hiroyuki Imanaka, Koreyoshi Imamura

    COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS   495   39 - 45   2016.4

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher: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

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

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

    FOOD CHEMISTRY   197   1136 - 1142   2016.4

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    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 &gt;= 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

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  • 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 Reviewed

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

    BIOTECHNOLOGY PROGRESS   32 ( 2 )   527 - 534   2016.3

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher: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

    DOI: 10.1002/btpr.2232

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  • Improvement of Biomolecular Interaction Detection Sensitivity through Molecular Design of Cushion Protein

    Imanaka Hiroyuki, Date Koki, Matoba Haruka, Ishida Naoyuki, Imamura Koreyoshi

    Abstract of annual meeting of the Surface Science of Japan   36   37 - 37   2016

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    Language:Japanese   Publisher:The Surface Science Society of Japan  

    DOI: 10.14886/sssj2008.36.0_37

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

    Soga Yuhei, Imanaka Hiroyuki, Imamura Koreyoshi, Ishida Naoyuki

    ADVANCED POWDER TECHNOLOGY   26 ( 6 )   1729 - 1733   2015.11

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

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

    JOURNAL OF FOOD ENGINEERING   155   37 - 44   2015.6

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher: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

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

    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   2015.4

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher: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.

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

    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   2014.6

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    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

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

    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   2014.6

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    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.

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

    Yuuhei Soga, Hiroyuki Imanaka, Koreyoshi Imamura, Naoyuki Ishida

    Advanced Powder Technology   51 ( 5 )   343 - 348   2014

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  • 2P085 Design of highly sensitive peptide-protein interaction detection system adopting CS complex formation as the model(01F. Protein: Engineering,Poster,The 52nd Annual Meeting of the Biophysical Society of Japan(BSJ2014))

    Matsushita Runa, Ishida Naoyuki, Imamura Koreyoshi, Imanaka Hiroyuki

    Seibutsu Butsuri   54 ( 1 )   S209   2014

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    DOI: 10.2142/biophys.54.S209_1

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  • 2P078 Screening of a novel gold affinity peptide and its application on protein immobilization(01D. Protein: Function,Poster,The 52nd Annual Meeting of the Biophysical Society of Japan(BSJ2014))

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

    Seibutsu Butsuri   54 ( 1 )   S207   2014

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

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

    JOURNAL OF PHARMACEUTICAL SCIENCES   102 ( 7 )   2187 - 2197   2013.7

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    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

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

    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   2013.4

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    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.

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  • The Discoidin Domain of Bacillus circulans beta-Galactosidase Plays an Essential Role in Repressing Galactooligosaccharide Production Reviewed

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

    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY   77 ( 1 )   73 - 79   2013.1

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    The recently cloned beta-galactosidase from Bacillus circulans ATCC 31382, designated BgaD, contains a multiple domain architecture including a F5/8 type C domain or a discoidin (DS) domain in the C-terminal peptide region. Here we report that the DS domain plays an essential role in repressing the production of galactooligosaccharides (GOSs). We prepared deletion mutants and point-mutated forms of rBgaD-A (deletion of the BgaD signal peptide) to compare their reaction behaviors. The yields of GOSs for all of the point-mutated forms as well as the deletion mutants of rBgaD-As increased as compared to rBgaD-A. In particular, W1540A mutant BgaD-A (rBgaD-A_W1540A) produced much more GOSs than rBgaD-A. Surface plasmon resonance experiments indicated that both the wildtype and the W1540A mutant DS domains showed high affinity for galactosyllactose. rBgaD-A, which has a wild-type DS domain, showed high hydrolytic activity toward galactosyllactose, while the hydrolytic activities of rBgaD-D, without a DS domain, and rBgaD-A_W1540A, with a mutant DS domain were extremely low. The findings obtained in this study indicate that the wild-type DS domain of rBgaD-A has a function that aids galactosyllactose molecules to be properly oriented within the active site, so that they can be hydrolyzed efficiently to produce galactose/glucose by inhibiting the accumulation of GOSs.

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  • Cloning and Expression of a beta-Galactosidase Gene of Bacillus circulans Reviewed

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

    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY   75 ( 6 )   1194 - 1197   2011.6

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    A gene of beta-galactosidase from Bacillus circulans ATCC 31382 was cloned and sequenced on the basis of N-terminal and internal peptide sequences isolated from a commercial enzyme preparation, Biolacta (R). Using the cloned gene, recombinant beta-galactosidase and its deletion mutants were overexpressed as His-tagged proteins in Escherichia coli cells and the enzymes expressed were characterized.

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  • Causes of the Production of Multiple Forms of beta-Galactosidase by Bacillus circulans Reviewed

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

    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY   75 ( 2 )   268 - 278   2011.2

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    The presence of multiple types of beta-galactosidases in a commercial enzyme preparation from Bacillus circulans ATCC 31382 and differences in their transgalactosylation activity were investigated. Four beta-galactosidases, beta-Gal-A, beta-Gal-B, beta-Gal-C, and beta-Gal-D, which were immunologically homologous, were isolated and characterized. The N-terminal amino acid sequences of all of the enzymes were identical and biochemical characteristics were similar, except for galactooligosaccharide production. beta-Gal-B, beta-Gal-C, and beta-Gal-D produced mainly tri- and tetra saccharides at maximum yields of 20-30 and 9-12%, while beta-Gal-A produced trisaccharide with 7% with 5% lactose as substrate. The Lineweaver-Burk plots for all of the enzymes, except for beta-Gal-A, showed biphasic behavior. beta-Gal-A was truncated to yield multiple beta-galactosidases by treatment with protease isolated from the culture broth of B. circulans. Treatment of beta-Gal-A with trypsin yielded an active 91-kDa protein composed of 21-kDa and 70-kDa proteins with characteristics similar to those for beta-Gal-D.

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  • An archaeal 2-deoxyribose 5-phosphate aldolase that exhibits closer homology to bacteria rather than archaea Reviewed

    Naeem Rashid, Hiroyuki Imanaka, Tadayuki Imanaka

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

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

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

    JOURNAL OF BIOSCIENCE AND BIOENGINEERING   110 ( 3 )   281 - 287   2010.9

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    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.

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

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

    JOURNAL OF BIOSCIENCE AND BIOENGINEERING   109 ( 3 )   267 - 273   2010.3

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    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.

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  • Impacts of Compression on Crystallization Behavior of Freeze-Dried Amorphous Sucrose Reviewed

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

    JOURNAL OF PHARMACEUTICAL SCIENCES   99 ( 3 )   1452 - 1463   2010.3

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    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

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  • 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

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    DOI: 10.11491/scej.2010f.0.1003.0

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  • 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

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    DOI: 10.11491/scej.2010f.0.997.0

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  • 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

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  • 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

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  • Development of peptide immobilization method using PS-tagged cushion protein Reviewed

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

    JOURNAL OF BIOSCIENCE AND BIOENGINEERING   108   S161 - S161   2009.11

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

    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   2009.10

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    The cathodic electrolysis of H2O2 (H2O2 + e(-) -&gt; 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.

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  • 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 Reviewed

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

    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY   73 ( 9 )   1940 - 1947   2009.9

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    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).

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

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

    JOURNAL OF BIOTECHNOLOGY   141 ( 3-4 )   160 - 165   2009.5

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    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.

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

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

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

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    We aimed to produce ethanol efficiently by enzymatic saccharification coupled with ethanol fermentation using wheat bran as a biomass. For this purpose, we examined pretreatment conditions of biomass and a combination of commercially available enzyme products for saccharification. When a 3.3% (w/v) wheat bran suspension was pretreated using subcritical water at 140℃ with a holding time of 0h, followed by saccharification at 45℃ using a mixture of commercially available Meiselase (composed of cellulase, cellobiase/β-glucosidase, and xylanase) and Novozyme^[○!R] 188 (composed of cellobiase/β-glucosidase, α-amylase, and glucoamylase) at a ratio of 4 to 1 by weight, glucose was released at 10.6g/l, which corresponded to 90% of the value calculated on the basis of the total amount of glucose-based saccharides contained in the wheat bran. On the other hand, from a pretreated 33% (w/v) wheat bran suspension, 85g/l glucose was produced, which corresponded to only 72% of the theoretical value, owing to the inhibitory effect of glucose on β-glucosidase activity. However, when fermentation was carried out at 30℃ following 24-h saccharification of the pretreated wheat bran using a mixture of Meiselase and Novozyme^[○!R] 188, the inhibitory effect of glucose was considered to be reduced and as a result, after 21-h fermentation, ethanol was produced at 5.2% (w/v), which corresponded to 88% of the theoretical maximum value.

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  • 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

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    DOI: 10.11491/scej.2009f.0.934.0

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  • 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

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    DOI: 10.11491/scej.2009f.0.1060.0

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  • 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

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    DOI: 10.11491/scej.2009f.0.779.0

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  • 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

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    DOI: 10.11491/scej.2009.0.606.0

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  • 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

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

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

    Current Proteomics   5 ( 3 )   161 - 175   2008.10

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    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

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  • True density analysis of a freeze-dried amorphous sugar matrix Reviewed

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

    JOURNAL OF PHARMACEUTICAL SCIENCES   97 ( 7 )   2789 - 2797   2008.7

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    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.

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

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

    JOURNAL OF PHARMACEUTICAL SCIENCES   97 ( 1 )   519 - 528   2008.1

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    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.

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  • 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

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    DOI: 10.11491/scej.2008.0.418.0

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

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

    SPECTROSCOPY LETTERS   41 ( 6 )   305 - 312   2008

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    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.

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  • 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

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    DOI: 10.11491/scej.2008.0.339.0

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  • 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

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    DOI: 10.11491/scej.2008.0.378.0

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  • 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

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    DOI: 10.11491/scej.2008.0.345.0

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  • 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

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    DOI: 10.11491/scej.2008f.0.175.0

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  • 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

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    DOI: 10.11491/scej.2008f.0.955.0

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

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

    INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES   41 ( 3 )   281 - 285   2007.8

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    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.

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  • 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 Reviewed

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

    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY   71 ( 6 )   1582 - 1586   2007.6

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    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.

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  • Cloning and characterization of penicillin V acylase from Streptomyces mobaraensis Reviewed

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

    JOURNAL OF BIOTECHNOLOGY   128 ( 4 )   788 - 800   2007.3

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    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.

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

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

    JOURNAL OF BIOTECHNOLOGY   128 ( 2 )   354 - 361   2007.2

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    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.

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

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

    JOURNAL OF BIOTECHNOLOGY   127 ( 2 )   288 - 299   2007.1

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    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.

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  • 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

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  • 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

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  • 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

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  • 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

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  • 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

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  • 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

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  • 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

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  • 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

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

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

    JOURNAL OF BIOSCIENCE AND BIOENGINEERING   102 ( 5 )   470 - 473   2006.11

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    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.

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

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

    MOLECULAR MICROBIOLOGY   61 ( 4 )   898 - 909   2006.8

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    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.

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

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

    JOURNAL OF PHYSICAL CHEMISTRY B   110 ( 31 )   15094 - 15099   2006.8

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    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.

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

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

    PROTEIN EXPRESSION AND PURIFICATION   47 ( 2 )   607 - 613   2006.6

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    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.

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

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

    BIOTECHNOLOGY PROGRESS   22 ( 2 )   401 - 405   2006.3

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    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.

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

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

    BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS   341 ( 4 )   911 - 916   2006.3

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    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.

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  • 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 Reviewed

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

    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY   54 ( 1 )   72 - 78   2006.1

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    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.

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  • 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

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    DOI: 10.11491/scej.2006f.0.413.0

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  • 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

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    DOI: 10.11491/scej.2006f.0.996.0

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  • 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

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    DOI: 10.11491/scej.2006f.0.995.0

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  • 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

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    DOI: 10.11491/scej.2006f.0.1002.0

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  • 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

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  • Purification and characterization of a novel aminoacylase from Streptomyces mobaraensis Reviewed

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

    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY   69 ( 10 )   1914 - 1922   2005.10

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    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.

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  • A novel epsilon-lysine acylase from Streptomyces mobaraensis for synthesis of N epsilon-acyl-L-lysines Reviewed

    M Koreishi, R Kawasaki, H Imanaka, K Imamura, K Nakanishi

    JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY   82 ( 9 )   631 - 637   2005.9

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    A novel epsilon-lysine acylase (N-6-acyl-L-lysine amido-hydrolase; EC 3.5.1.17) was isolated from Streptomyces mobaraensis and purified to homogeneity by SDS-PAGE from the culture broth. The purified enzyme was monomeric, with a molecular mass of approximately 60 kDa. The enzyme was inactivated by the presence of 1,10-phenanthroline and activated in the presence of Co2+ and Zn2+. The enzyme showed a pH optimum of 8.0 and was stable at temperatures of up to 50 degrees C for 1 h at pH 8.0. The enzyme specifically catalyzed the hydrolysis of the amide bond of various N epsilon-acyl-L-lysines. Furthermore, the enzyme efficiently catalyzed the synthesis of NF-acyl-L-lysines with fatty and aromatic acyl groups in an aqueous buffer. in the syntheses of N epsilon-decanoyl-L-lysine, N epsilon-lauroyl-L-lysine, and N epsilon-myristoyl-L-lysine, the product precipitated and the yield was 90% or higher using 10 mM FA and 0.5 M L-lysine as the substrate.

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  • Continuous hydrogen production by the hyperthermophilic archaeon, Thermococcus kodakaraensis KOD1 Reviewed

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

    JOURNAL OF BIOTECHNOLOGY   116 ( 3 )   271 - 282   2005.3

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    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.

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  • 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

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

    Zhao Chunhui, Imanaka Hiroyuki, Imamura Koreyoshi, Nakanishi Kazuhiro

    2005   271 - 271   2005

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    DOI: 10.11491/scej.2005.0.271.0

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  • 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

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  • 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

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  • 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

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  • 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

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  • 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

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

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

    JOURNAL OF BACTERIOLOGY   186 ( 17 )   5799 - 5807   2004.9

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    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.

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  • 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 Reviewed

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

    JOURNAL OF BACTERIOLOGY   186 ( 13 )   4185 - 4191   2004.7

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    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

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

    H Imanaka, T Fukui, H Atomi, T Imanaka

    JOURNAL OF BIOSCIENCE AND BIOENGINEERING   94 ( 3 )   237 - 243   2002.9

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    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.

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

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

    JOURNAL OF BIOLOGICAL CHEMISTRY   277 ( 34 )   30649 - 30655   2002.8

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher: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

    Web of Science

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  • Removal of aromatic compounds in gas by electron attachment Reviewed

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

    INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH   37 ( 7 )   2770 - 2774   1998.7

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher: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

    Web of Science

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Books

  • バイオ実験を安全に行うために

    今中 洋行( Role: Contributor ,  5章 情報の保管と管理 pp.108-110)

    化学同人  2018 

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  • 細胞・生体分子の固定化と機能発現

    今中 洋行( Role: Contributor ,  第6章 クッションタンパク質を用いたリガンド分子固定化法の開発と利用)

    シーエムシー出版  2018 

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  • Encyclopedia of Industrial Biotechnology : Bioprocess, Bioseparation, and Cell Technology (ed. by M.C. Flickinger)

    Nakanishi Kazuhiro, Imanaka Hiroyuki, Tanaka Soukichi( Role: Contributor ,  Chapter: Membrane-Surface Liquid Culture, Fungi)

    Wiley  2009 

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  • 第5版実験化学講座29 -バイオテクノロジーの基本技術-

    丸善  2006 

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Presentations

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Industrial property rights

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Awards

  • YABEC 2019 Best Poster Presentation Award

    2019.11   AFOB  

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  • 農芸化学会中四国支部奨励賞

    2013  

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    Country:Japan

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  • ACB2011 Outstanding Young Scientist and Student Award

    2011.5   AFOB  

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    Country:Japan

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  • YABEC 2010 Best Poster Presentation Award

    2010   AFOB  

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Research Projects

  • Creation of functional cushion protein for a highly sensitive bimolecular interaction detection system by rational molecular design

    Grant number:15K06582  2015.04 - 2018.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

    Imanaka Hiroyuki

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    Grant amount:\4810000 ( Direct expense: \3700000 、 Indirect expense:\1110000 )

    The applications of combinations of surface affinity peptide-tag and cushioning scaffold protein, CutA1 from a hyperthermophilic archaeon, were examined in detail to construct functional ligand biomolecular immobilized surfaces. Through the evaluations of non-labelled biomolecular interaction detection after immobilizations of rationally designed various CutA1s by quartz crystal microbalance (QCM), the importance of precise control of ligand orientation with avoiding steric hindrance to construct highly sensitive interaction detection system was clarified. On the other hand, an original affinity peptide of gold nanoparticle (AuNP-tag) was screened and its applications for sensitive colorimetric interaction detection was demonstrated with CutA1 scaffold. In addition, possible VHH antibody insertion site was successfully found in CutA1 and thus expansion of molecular design tolerance of CutA1 was verified.

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  • Application of energy conversion apparatus consisting of photosystem I complex fused with tailor-made peptide tag

    Grant number:15K14551  2015.04 - 2017.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Challenging Exploratory Research

    Takahashi Yuichiro, IMANAKA Hiroyuki

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    Grant amount:\3900000 ( Direct expense: \3000000 、 Indirect expense:\900000 )

    We have developed a chloroplast battery cell which consists of photosynthetic proteins bound to an electrode and produces electricity under illumination. Peptide tags (Au-tags), which have an affinity to gold electrodes, have been screened by the bio-panning method using T7 bacteriophage. We genetically fused the resulting tags to one of the photosystem I (PSI) reaction center proteins and expressed it in the chloroplast of the green alga Chlamydomonas reinhardtii. The PSI complex containing an Ag-tag was purified and was bound to the electrode, resulting in the chloroplast battery cell. We measured electricity of the chloroplast battery cells with wild-type and Au-tag fused PSI complexes in the presence of artificial electron donors under illumination. It was found that only the chloroplast battery cell of Au-tagged PSI complex exhibited electricity. In conclusion, our strategy to use affinity peptide tag to bind PSI complex on the electrode is effective and useful.

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  • 親水性ポリスチレン高親和性ペプチドを用いた革新的蛋白質相互作用解析システムの創製

    Grant number:19656221  2007 - 2008

    日本学術振興会  科学研究費助成事業  萌芽研究

    中西 一弘, 今村 維克, 今中 洋行

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    Grant amount:\3300000 ( Direct expense: \3300000 )

    本年度は、親水性ポリスチレン親和性ペプチドを用いた、1)コアストレプトアビジン(Core-SA)-DNA相互作用解析と2)相互作用に関与する機能性ペプチド部位を連結したクッションタンパク質を用いた相互作用解析を計画したが、両課題共に、初期の予定を達成できた。1)の課題においては、4量体のCore-SAに連結する親和性ペプチド(PSペプチド)の個数を変えて、その固定化特性とオリゴDNAとの相互作用をELISA法で検出した。結果として、4つのPSペプチドを連結したCore-SAは共存する高濃度牛血清アルブミンとの競合に影響されることなく、最も強固に固定化できることを示した。さらに、ビオチン標識オリゴDNAを連結したペプチドタグ連結コアストレプトアビジンは、市販のSA-coated plateよりも高い検出感度を示すことがわかった。一方、2)の課題に関しては,システイン合成酵素を構成するO-acetylserine sulfhydryrase-A(OASS-A)とそのC末端で相互作用することが知られているserine acetyltransferase(SAT)との間の相互作用に着目した。SATのC末端20残基からなるオリゴペプチドを、そのN末端にPSペプチドを連結したクッションタンパク質(RNaseHII)のC末端に連結し、オリゴペプチドのC末端アミノ酸を変化させてOASS-Aとの相互作用をELISA法で検出した結果、C末端アミノ酸がイソロイシンの野生型ペプチドを提示させた場合にのみ、相互作用することがわかった。同様に、Strep-tagIIをクッションタンパク質に提示したが、そのN末端をクッションタンパク質に向けて結合した場合にのみstreo-tactinと強い相互作用を示した。これらの結果から、本研究で検討した、親水性PS特異的親和性ペプチを用いる相互作用解析方法は、極めて高い検出感度と特異性を有することが明らかにされた。

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  • 固体材料表面への新規なタンパク質付着配向制御技術の開発

    Grant number:17760624  2005 - 2007

    日本学術振興会  科学研究費助成事業  若手研究(B)

    今中 洋行

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    Grant amount:\3300000 ( Direct expense: \3300000 )

    固体表面との相互作用を緩和する「クッションタンパク質」として,物理的強度が高い単量体タンパク質である超好熱菌Thermococcus Kodakaraensis由来Ribonuclease HII(HII)を利用し,モデル表面としては親水性ポリスチレン(PS)およびステンレス(SUS316L)を用いて,バイオ分子の固定化特性の調査を行った.N末端に各種固体表面親和性ペプチドを連結したHIIのC末端にHis-tag(モデルペプチド) または緑色蛍光タンパク質(GFP)(モデルタンパク質)を連結した各種キメラタンパク質をそれぞれ発現,精製した.そして,まずこれらを親水性PSプレート上に固定化し,ELISAによって固定化率,検出感度を調べた.その結果,His-tagについては,表面高親和性タグ(PS-tag : RAFIASRRIKRP)+HIIに連結することで1000倍濃度のタンパク質(BSA)共存下においても優先的に表面に固定化できることがわかった.さらにHIIのC末端にフレキシブルリンカー(FL : GGGS)を挿入することにより,酵素標識抗His抗体を用いた検出の感度向上がみられた.また,GFPを固定化した場合,PS-tagだけではなくHIIも連結した方が,より強固な固定化が可能であった.一方,ステンレス表面へのペプチド(His-tag)の固定化についても検討を行ったところ,ステンレス高親和性タグ(SS-tag :ADGEGEWTSGRR)+FLに連結した場合に比べ,HIIをSS-tagとFLとの間に挿入することで,検出感度が劇的に向上した.すなわち,抗体に標識化された検出用酵素とステンレス表面との相互作用がHIIの挿入により高度に低減されたと考えられた.これらの結果から,固体表面親和性ペプチドおよびFLを連結したHIIを「クッションタンパク質」として固定化対象のバイオ分子に連結することで,各種表面上に対して,配向および構造を維持しつつ優先的かつ機能的に固定化しうることがわかった.

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  • Molecular mechanism for adsorption and adsorption of soil components formed on the surface of equipment wall during manufacturing and development of an efficient cleaning method

    Grant number:16206076  2004 - 2007

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (A)

    NAKANISHI Kazuhiro, IMAMURA Koreyoshi, IMANAKA Hiroyuki

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    Grant amount:\46800000 ( Direct expense: \36000000 、 Indirect expense:\10800000 )

    In various manufacturing processes, cleaning of the equipment and piping systems used for manufacturing of various products is requisite for maintaining sanitary conditions and/or functions of the equipments. In particular, in the food- and bio-products manufacturing processes, a large amount of energy and detergents are usually consumed in addition to time, since soils or residues of the products strongly interact with the equipment surface. In this study, we studied adsorption mechanisms of various proteins/peptides and low-molecular weight substances as a model soil component on the surfaces of various metal oxides, plastics, and glasses. We clarified the molecular mechanisms for reversible/irreversible adsorptions, states and orientation of the molecules adsorbed, the effects of the pI values of the metal oxide surfaces/solution pHs on the adsorption characteristics, and conformational change of the adsorbed proteins, on the basis of adsorption/desorption experiments, IR spectrum analyses, and molecular calculations. Furthermore, we investigated the effects of various factors such as the kinds of the co-existing salts and their concentrations on the removal rates of the metal oxide surface fouled with proteins, using H2O2-electrolysis cleaning method that was developed by the author's group. Furthermore, we developed a method to immobilize proteins with controlled orientation and structure for various uses in chip-based biotechnology, which was derived in the course of investigation on the adsorption mechanism of proteins.

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