Papers - KOUMOTO Kazuya
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Synthesis and Immunestimulating Activity of Lactobacilli-Originated Polysaccharide-Polymeric Microparticle Conjugates Reviewed
Koji Nagahama, Takayuki Kumano, Tsubasa Nakata, Hirokazu Tsuji, Kaoru Moriyama, Kan Shida, Koji Nomoto, Katsuyoshi Chiba, Kazuya Koumoto, Jun Matsui
Langmuir 31 1489 - 1495 2015
Joint Work
Authorship：Lead author
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Immunestimulating Activity of Lactobacilli-mimicking Microparticles modified withPolysaccharide-Peptidoglycan Complex derived from L. casei Shirota Strain Invited
Kazuya Koumoto, Koji Nagahama, Jun Matsui
BIOINDUSTRY 32 ( 9 ) 42 - 47 2015
Joint Work
Authorship：Lead author
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Enhanced Immunostimulating Activity of Lactobacilli-Mimicking Materials by Controlling Size Reviewed
Koji Nagahama, Takayuki Kumano, Yuichi Nakagawa, Naho Oyama, Hirokazu Tsuji, Kaoru moriyama, Kan Shida, Koji Nomoto, Katsuyoshi Chiba, Kazuya Koumoto, Jun Matsui
Bioconjugate Chemistry 26 ( 8 ) 1775 - 1781 2015
Joint Work
Authorship：Lead author
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Significance of anionic functional group in betaine-type metabolite analogs on the facilitation of enzyme reactions International journal
Yuichi Nakagawa, Kotomi Takagi, Ryutaro Genjima, Kazuya Koumoto
BIOPROCESS AND BIOSYSTEMS ENGINEERING 38 ( 9 ) 1811 - 1817 2015
Joint Work
Authorship：Lead author Publisher：SPRINGER
Using synthetic sulfobetaine library, the enzyme activation behavior has been investigated. Comparison of enzyme activation behavior revealed that sulfobetaines equally facilitate enzyme reactions, being consistent with that of carboxybetaines. The subsequent kinetic and solution property analyses clarified that both the kinetic parameter and hydration property changes are identical with those of carboxybetaines, indicating that the difference in the anionic functional group of the betaine structure scarcely affects the enzyme activation. On the other hand, comparison of carboxy- or sulfo-betaines with tetraalkylammonium salts, whose counteranion binds to the ammonium cation intermolecularly, revealed that the activation ability for enzymes of tetraalkylammonium salts is considerably smaller than that of carboxy- or sulfo-betaines. These findings give us a hint to design the useful betaine-type enzyme activators.
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Enhanced Chromogenic Sensitivity of Horseradish Peroxidase-Catalyzed Oxidative Reactions in the Presence of Betaine-Type Metabolite Analogs Reviewed
Kotomi Takagi, Yasuhiro Kashima, Satoshi Fujii, Kazuya Koumoto
BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 88 ( 8 ) 1074 - 1082 2015
Joint Work
Authorship：Lead author Publisher：CHEMICAL SOC JAPAN
Horseradish peroxidase (HRP), a well-known oxidase, is frequently used in the diagnostic field as a labeling enzyme, where it amplifies the substrate binding signal of antibodies. Though practical for detecting moderate amounts of substrate, there is strong demand for further development of its sensitivity to detect minuscule quantities of biomarkers. Recently, we found that betaine-type cellular metabolite analogs facilitate enzymatic hydrolysis just by dissolving them into the reaction buffer. In the present study, using the analog (2-(N,N,N-tri-n-butylammonium) acetate) and various colorimetric substrates of HRP, we investigated the activation behavior of HRP. As a result, the analog structure- and concentration-dependently facilitated the various HRP-catalyzed oxidative reactions. Interestingly, the analog facilitated not only the reaction rate but also the chromogenic sensitivity. Kinetic and structural analyses revealed that the increased chromogenic sensitivity is related to the enhancement of the conformational flexibility in the substrate binding site in HRP by addition of the analog, which diminishes the binding affinity between HRP and large substrates. The finding serves to create practical applications of the analogs for increased detection sensitivity of HRP-related clinical agents.
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Mechanistic study on the facilitation of enzymatic hydrolysis by alpha-glucosidase in the presence of betaine-type metabolite analogs Reviewed
Yuichi Nakagawa, Shiro Sehata, Satoshi Fujii, Hiroaki Yamamoto, Akihiko Tsuda, Kazuya Koumoto
TETRAHEDRON 70 ( 35 ) 5895 - 5903 2014.9
Publisher：PERGAMON-ELSEVIER SCIENCE LTD
Recently we reported that betaine-type metabolite analogs structure-dependently facilitate enzymatic hydrolysis reaction for alpha-glucosidases, beta-glucosidases, and alkaliphosphatases. To understand the facilitation mechanism for enzymes, in this study we expanded the analog library and measured the properties of analog solutions. The structural investigation on alpha-glucosidase-mediated hydrolysis reaction indicated that suitable structures to facilitate the enzyme reaction efficiently should have the ammonium cation in the betaine structure possess triplicate aliphatic chains from Cl to C7 without any polar functional groups. Analyses of the solution properties revealed that such analogs possess a large hydration layer with low water density. Such a specific hydration environment is generated by the characteristic structure of the betaine-type metabolite analogs. The characteristic hydration indirectly regulates enzyme activity and stability. These findings not only increase our understanding enzyme activation by betaine-type metabolite analogs, but also will contribute to the molecular design of enzyme regulators. (C) 2014 Elsevier Ltd. All rights reserved.
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Mechanistic study on the facilitation of enzymatic hydrolysis by α-glucosidase in the presence of betaine-type metabolite analogs Reviewed
Yuichi Nakagawa, Shiro Sehata, Satoshi Fujii, Hiroaki Yamamoto, Akihiko Tsuda, Kazuya Koumoto
Tetrahedron 70 5895 - 5903 2014
Joint Work
Authorship：Lead author
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Cellular zwitterionic metabolite analogs simultaneously enhance reaction rate, thermostability, salt tolerance, and substrate specificity of alpha-glucosidase Reviewed
Eisuke Deguchi, Kazuya Koumoto
Bioorganic and Medicinal Chemistry 19 3128 - 3134 2011.4
Joint Work
Authorship：Lead author
天然の代謝産物を模倣し、化学的に合成した代謝産物アナログがα−グルコシダーゼ、β−グルコシダーゼ、アルカリフォスファターゼといった加水分解酵素の活性（反応速度、耐熱性、耐塩性、基質選択性等）を溶液に共存させるだけで向上させることを明らかとした。
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Reversible stability switching of a hairpin DNA via a photo-responsive linker unit Invited Reviewed
Li Wu, Kazuya Koumoto, Naoki Sugimoto
Chemical Communications 1915 - 1917 2009.4
Joint Work
ヘアピンDNAのループ部位に導入し、光異性化によってヘアピンDNA全体の安定性を制御できる新規光応答性ユニットの開発に成功した。このユニットをヘアピン部位に導入したDNAは紫外光、可視光の照射に伴って安定性が可逆的に制御することができた。
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Structural effect of synthetic zwitterionic cosolutes on the stability of DNA duplexes Reviewed
甲元一也
Tetrahedron ( 64 ) 168 - 174 2008.11
Joint Work
Authorship：Lead author
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Artificial G-wire Switch with 2,2’-Bipyridine Units Responsive to Divalent Metal Ions
甲元一也
J. Am. Chem. Soc ( 129 ) 5919 - 5925 2007.11
Single Work
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５）天然高分子 核酸 エネルギーデータベースに基づく核酸医薬の設計
甲元一也
絵で見てわかるナノDDS 遺伝子医学MOOK別冊（メディカルドゥ） 63 - 69 2007.11
Single Work
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Conformational switch of a functional nanowire based on the DNA G-quadruplex
甲元一也
Nucleic Acids Symp. Ser. ( 51 ) 251 - 252 2007.11
Single Work
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Delivery of antisense oligonucleotides to nuclear telomere RNA by use of a complex between polysaccharide and polynucleotide
甲元一也
Bull. Chem. Soc. Jpn ( 80 ) 1091 - 1098 2007.11
Single Work
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Schizophyllan, beta-1,3-glucan,-oligoamine conjugates as non-viral vector Reviewed
Takeshi Nagasaki, Atsushi Uno, Kazuya Koumoto, Kazuo Sakurai, Seiji Shinkai
ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY 234 2007.8
Publisher：AMER CHEMICAL SOC
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Galactose-PEG Dual Conjugation of b-(1→3)-D-glucan schizophyllan for antisense oligonucleotide delivery to enhance cellular uptake
甲元一也
Biomaterials, ( 27 ) 1626 - 1635 2006.11
Single Work
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CpG DNA/zymosan complex to enhance cytokine secretion owing to the cocktail effect
甲元一也
Bioorg. Med. Chem. Lett ( 16 ) 1301 - 1304 2006.11
Single Work
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In situ monitoring of polysaccharide-polynucleotide interaction using a schizophyllan-immobilized QCM device
甲元一也
Sensors & Actuators B: Chemicals ( 105 ) 490 - 494 2005.11
Single Work
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Transferrin-appended b-(1→3)-D-glucan schizophyllan for antisense oligonucleotides delivery to enhance the cellular uptake
甲元一也
J. Contr. Rel. ( 108 ) 529 - 539 2005.11
Single Work
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Transferrin-appended b-(1→3)-D-glucan schizophyllan for antisense oligonucleotides delivery to enhance the cellular uptake
甲元一也
e-J. Surface Sci. Nanotech ( 3 ) 195 - 202 2005.11
Single Work