Papers - KOUMOTO Kazuya
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Inhibitory Effects of Shikonin Dispersion, an Extract of Lithospermum erythrorhizon Encapsulated in β-1,3-1,6 Glucan, on Streptococcus mutans and Non-Mutans Streptococci Reviewed
Ryota Nomura, Yuto Suehiro, Fumikazu Tojo, Saaya Matayoshi, Rena Okawa, Masakazu Hamada, Shuhei Naka, Michiyo Matsumoto-Nakano, Rika Unesaki, Kazuya Koumoto, Keiko Kawauchi, Takahito Nishikata, Tatsuya Akitomo, Chieko Mitsuhata, Masatoshi Yagi, Toshiro Mizoguchi, Koki Fujikawa, Taizo Taniguchi and Kazuhiko Nakano
25 1075 2024.1
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Inhibitory Effect of Adsorption of Streptococcus mutans onto Scallop-Derived Hydroxyapatite Reviewed
Momoko Usuda, Mariko Kametani, Masakazu Hamada, Yuto Suehiro, Saaya Matayoshi, Rena Okawa, Shuhei Naka, Michiyo Matsumoto-Nakano, Tatsuya Akitomo, Chieko Mitsuhata, Kazuya Koumoto, Keiko Kawauchi, Takahito Nishikata, Masatoshi Yagi, Toshiro Mizoguchi, Koki Fujikawa, Taizo Taniguchi, Kazuhiko Nakano and Ryota Nomura
Int J Mol Sci 24 11371 2023.7
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ポリエチレングリコールによるアトピー性皮膚炎予防の可能性
厳原美穂、甲元一也
Fragrance Journal 50 ( 11 ) 54 - 57 2022.11
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Hydrostatic Pressure-Regulated Cellular Calcium Responses. Reviewed International journal
Minami Fukuchi, Kotaro Oyama, Hiroaki Mizuno, Akihisa Miyagawa, Kazuya Koumoto, Gaku Fukuhara
Langmuir : the ACS journal of surfaces and colloids 37 ( 2 ) 820 - 826 2021.1
Joint Work
Hydrostatic pressure control has attracted much attention and presents a still challenging objective from mechanobiological viewpoints. Herein, we reveal the calcium entry processes in HeLa cells by means of hydrostatic pressure spectroscopy. The steady-state fluorescence spectral data comprehensively elucidated the factors controlling the outcomes of the hydrostatic pressure-stimulated calcium entry behavior. The present work leads to a new perspective on ion regulations in living cells and an attractive alternative to conventional mechanostimuli.
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Mechanism toward Turn-on of Polysaccharide-Porphyrin Complexes for Fluorescence Probes and Photosensitizers in Photodynamic Therapy in Living Cells Reviewed International journal
Shodai Hino, Rikushi Funada, Kouta Sugikawa, Riku Kawasaki, Kazuya Koumoto, Toshio Suzuki, Takeshi Nagasaki, Atsushi Ikeda
CHEMMEDCHEM 15 ( 1 ) 1 - 12 2020.10
Joint Work
Publisher：WILEY-V C H VERLAG GMBH
beta-(1,3-1,6)-D-Glucan, lambda-carrageenan, tamarind gum, and pullulan can dissolve various porphyrin derivatives via the formation of complexes in water using a high-speed vibration milling method. The aqueous solutions of the resulting complexes exhibit long-term stability. Despite the adverse effects of the self-quenching process, notable fluorescence and improved photodynamic activity of the polysaccharide-complexed porphyrin derivatives were observed in the presence of liposomes, micelles, cyclodextrins, and HeLa cells. It was noted that the type of porphyrins was more important than the type of polysaccharides present in the complex. Porphyrin self-aggregates were monodispersed in the lipid membranes of the liposomes and lysosomes. The polysaccharide-complexed porphyrin derivatives showed increased photodynamic activity toward HeLa cells under photoirradiation between 610 and 740 nm.
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Modification of the Release Rate of Curcumin from the Cavity of Renatured beta-1,3-1,6-Glucan Nanoparticles by Changing the Molecular Weight of the Constituent Polysaccharide Chains Reviewed
Yuki Nonoguchi, Ayumu Kodama, Rika Unesaki, Nanako Doi, Toshio Suzuki, Kazuya Koumoto
CHEMISTRY LETTERS 49 ( 10 ) 1150 - 1153 2020.7
Joint Work
Publisher：CHEMICAL SOC JAPAN
We prepared renatured beta-1,3-1,6-glucan nanoparticles from molecular-weight-fractionated beta-1,3-1,6-glucans to analyze the molecular effects on the inclusion and release of the guest molecule curcumin. Glucan molecular weight strongly affects the amount of curcumin included in the complexes and its release rate. We found that the slow release rate of the incorporated curcumin is attributed not only to the stabilized stacking structure but also the slow migration between the internal and surface cavities characteristic of polymeric materials.
DOI： 10.1246/cl.200366
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Solubilization of poorly water-soluble bioactive molecules in neutral aqueous media by complexation with renatured beta-1,3-1,6-glucan nanoparticles Reviewed International journal
Ayumu Kodama, Akifumi Nakagawa, Yuki Nonoguchi, Haruka Sakurai, Chieko Yano, Toshio Suzuki, Kazuya Koumoto
BIOPOLYMERS 111 ( 4 ) e23349 2020.2
Joint Work
Publisher：WILEY
The design of scaffolds for solubilizing/dispersing poorly water-soluble bioactive molecules in neutral aqueous media is a major challenge of functional food, pharmaceuticals, and cosmetics development, as highlighted by the plethora of corresponding solubilization/dispersion strategies. Herein, renatured beta-1,3-1,6-glucan (r-glucan) nanoparticles prepared by neutralization of alkali-denatured beta-1,3-1,6-glucan and subsequent centrifugation are used as a host to disperse water-insoluble bioactive molecules (curcumin, all-trans-retinoic acid, and rebamipide) by simple mixing of host and guest solutions. Curcumin in the r-glucan cavity is found to be stacked in the form of J-aggregates and twisted along the helix, and is demonstrated to be retained for significantly longer than curcumin in the corresponding gamma-cyclodextrin (gamma-CD) complex. Specifically, curcumin incorporated in gamma-CD is released within 5.5 hours, whereas that in the r-glucan complex is released very slowly, with 12% of curcumin in the latter complex retained after 31-day incubation at 37 degrees C. Thus, inclusion protocol simplicity and slow release ability make r-glucan nanoparticles a potential carrier scaffold for various applications.
DOI： 10.1002/bip.23349
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Improved Stability and Photodynamic Activity of Water-Soluble 5,15-Diazaporphyrins Incorporated in beta-(1,3-1,6)-d-Glucan with On-Off Switch Reviewed International journal
Shodai Hino, Shuhei Satake, Hideyuki Shinmori, Shigeki Kawabata, Kazuya Koumoto, Toshio Suzuki, Takeshi Nagasaki, Kouta Sugikawa, Riku Kawasaki, Atsushi Ikeda
CHEMISTRY-AN ASIAN JOURNAL 15 ( 3 ) 365 - 370 2019.12
Joint Work
Publisher：WILEY-V C H VERLAG GMBH
5,15-Diazaporphyrins, which have a large absorption at wavelengths over 600 nm, were dissolved in water by complex formation with beta-(1,3-1,6)-d-glucans. Aqueous solutions of these complexes were relatively stable compared with their trimethyl-beta-cyclodextrin-complexed analogues. beta-Glucan-complexed diazaporphyrins showed quenched fluorescence and had low singlet-oxygen-generation abilities owing to random self-aggregation. However, external stimuli, such as the presence of liposomes or intracellular uptake, restored the fluorescence and singlet-oxygen-generation abilities of beta-glucan-complexed diazaporphyrins. Consequently, beta-glucan-complexed diazaporphyrins showed very high photodynamic activities toward HeLa cells.
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Structural effect of amine N-oxides on the facilitation of alpha-glucosidase-catalyzed hydrolysis reactions Reviewed International journal
Takuma Aoki, Yuichi Nakagawa, Ryutaro Genjima, Kazuya Koumoto
BIOPROCESS AND BIOSYSTEMS ENGINEERING 43 ( 3 ) 541 - 548 2019.11
Joint Work
Publisher：SPRINGER
Activation and stabilization of enzymes is an important issue in their industrial application. We recently reported that synthetic betaines, derived from cellular metabolites, structure-dependently increased the activity and stability of various enzymes including hydrolases, oxidases, and synthetases simply by mixing them into the reaction buffer. In this report, we focus on amine N-oxides, which are similarly important metabolites in cells with a highly polarized N-oxide bond, and investigate their enzyme stabilization and activation behavior. It was revealed that synthetic amine N-oxides structure-dependently activate alpha-glucosidase-catalyzed hydrolysis reactions similarly to betaines. The subsequent comparison of the kinetic parameters, the optimal concentration range for activation, and the maximal activity, suggested that amine N-oxides facilitate hydrolysis reactions via the same mechanism as betaines, because no differences were confirmed. However, the enzyme stabilization effect of amine N-oxides was slightly superior to that of betaines and the temporal stability of the enzyme in aqueous solutions was higher in the low amine N-oxide concentration range. The rheological properties, CD spectra, and dynamic fluorescence quenching experiments suggested that the suppression of unfavorable conformational perturbation was related to the difference in the hydration environments provided by the surrounding water molecules. Thus, we clarified that amine N-oxides facilitate enzyme reactions as a result of their similarity to betaines and provide a superior stabilizing effect for enzymes. Amine N-oxides show potential for application in enzyme storage and long-term reactions.
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Turn-on fluorescence and photodynamic activity of beta-(1,3-1,6)-d-glucan-complexed porphyrin derivatives inside HeLa cells Reviewed International journal
Shodai Hino, Rikushi Funada, Kouta Sugikawa, Kazuya Koumoto, Toshio Suzuki, Takeshi Nagasaki, Atsushi Ikeda
PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES 18 ( 12 ) 2854 - 2858 2019.11
Joint Work
Publisher：ROYAL SOC CHEMISTRY
Fluorescence intensities of water-soluble beta-(1,3-1,6)-d-glucan (beta-1,3-glucan)-complexed porphyrin derivatives were very weak as a result of self-quenching. However, beta-1,3-glucan-complexed tetra(aminophenyl)porphyrin exhibited 'off-state' to 'on-state' fluorescence switching activity by intracellular uptake. Furthermore, the internalised complex showed a high level of photodynamic activity toward HeLa cells under photoirradiation at long wavelengths.
DOI： 10.1039/C9PP00208A
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研究課題設定を重視した科学技術人材育成プログラムROOTのデザインと実装
伊藤 真之, 臼井 英之, 長野 寛之, 巳波 弘佳, 甲元 一也, 蛯名 邦禎
日本科学教育学会年会論文集 43 399 - 400 2019.8
Joint Work
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Water Solubilization of Fullerene Derivatives by beta-(1,3-1,6)-D-Glucan and Their Photodynamic Activities toward Macrophages Reviewed International journal
Atsushi Ikeda, Tatsuya Iizuka, Naotake Maekubo, Kazuyuki Nobusawa, Kouta Sugikawa, Kazuya Koumoto, Toshio Suzuki, Takeshi Nagasaki, Motofusa Akiyama
CHEMISTRY-AN ASIAN JOURNAL 12 ( 10 ) 1069 - 1074 2017.3
Joint Work
Publisher：WILEY-V C H VERLAG GMBH
Anionic and neutral fullerene derivatives were dissolved in water by using beta-(1,3-1,6)-D-glucan (beta-1,3-glucan) as a solubilizing agent. In the water-solubilized complexes, the concentrations of fullerene derivatives were approximate to 0.30 mm and the average particle sizes were approximate to 90 nm. The beta-1,3-glucan-complexed fullerene derivative with a carboxylic acid was found to have higher photodynamic activity toward macrophages under visible-light irradiation (lambda > 610 nm) than other beta-1,3-glucan-complexed fullerene derivatives. This result suggests that carboxylic acid moieties in the complex enhance the binding affinity with beta-1,3-glucan receptors on the surface of macrophages when the beta-1,3-glucan is recognized. In contrast, all beta-1,3-glucan-complexed fullerene derivatives showed no photodynamic activity toward HeLa cells under the same conditions.
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Formation of beta-(1,3-1,6)-D-glucan-complexed [70]fullerene and its photodynamic activity towards macrophages Reviewed International journal
Atsushi Ikeda, Motofusa Akiyama, Kouta Sugikawa, Kazuya Koumoto, Yuta Kashijima, Jiawei Li, Toshio Suzuki, Takeshi Nagasaki
ORGANIC & BIOMOLECULAR CHEMISTRY 15 ( 9 ) 1990 - 1997 2017.2
Joint Work
Publisher：ROYAL SOC CHEMISTRY
[70] Fullerene was dissolved in water by complexation with beta-1,3-glucan using a mechanochemical highspeed vibration milling apparatus. The photodynamic activity of beta-1,3-glucan-complexed C-70 was highly dependent on the expression level of dectin-1 on the cell surfaces of macrophages. The photodynamic activity increased as a result of a synergistic effect between beta-1,3-glucan-complexed 1 '-acetoxychavicol acetate and the C-70 complex.
DOI： 10.1039/C6OB02747D
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Lipid-membrane-incorporated arylboronate esters as agents for boron neutron capture therapy. Reviewed International journal
Masafumi Ueda, Kengo Ashizawa, Kouta Sugikawa, Kazuya Koumoto, Takeshi Nagasaki, Atsushi Ikeda
Organic & biomolecular chemistry 15 ( 7 ) 1565 - 1569 2016.10
Joint Work
Publisher：ROYAL SOC CHEMISTRY
Arylboronate esters bearing methyl groups in both of their ortho positions were stably incorporated into lipid membranes at high concentrations without undergoing hydrolysis to the corresponding boronic acids. This method could be used in combination with previous methods to increase the maximum ratio of boron atoms in liposomal boron carriers.
DOI： 10.1039/C6OB02142E
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Increased yield of beta-glucosidase-catalyzed hydrolysis reactions in the presence of betaine-type metabolite analog Reviewed International journal
Shiro Sehata, Ryojun Suzuki, Kazuya Koumoto
BIOPROCESS AND BIOSYSTEMS ENGINEERING 40 ( 1 ) 153 - 159 2016.9
Joint Work
Publisher：SPRINGER
beta-Glucosidases (EC 3.2.1.21), abundant enzymes distributed in animals, plants and microorganism, has been generating lots of attentions for bioethanol production from cellulosic biomass. In this study, using three different origins of beta-glucosidases, glucose productivity of beta-glucosidase-catalyzed hydrolysis reactions in the presence of synthetic betaine-type metabolite analog (2-N,N,N-tri-n-butylammonium) acetate, was investigated. By the addition of the analog, the hydrolysis yields for all beta-glucosidases was highly improved from 4-13 to 64-100 %. To understand the factors affecting on the yield enhancements, the kinetic parameters, inhibition constants of end-product and temporal stability of beta-glucosidases were compared. As a result, enhancement of the yields is mainly related to the increase in the temporal stability of beta-glucosidases in the presence of the analog. The present findings lead to not only improve the glucose productivity of beta-glucosidase-catalyzed hydrolysis reaction toward bioethanol production but also apply to a new stabilization method for various unstable enzymes.
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Cryoprotective ability of betaine-type metabolite analogs during freezing denaturation of enzymes International journal
Yuichi Nakagawa, Masahiro Sota, Kazuya Koumoto
BIOTECHNOLOGY LETTERS 37 ( 8 ) 1607 - 1613 2015.8
Publisher：SPRINGER
To evaluate an analog library of betaine-type cellular metabolites, which are naturally found in polar fish for survival in subzero temperatures, for preventing denaturation of enzymes during freezing.Comparison of the cryoprotective ability of reported cryoprotectants, such as dimethylsulfoxide, glycerol, ectoine, hydroxyectoine, and trehalose, with betaine-type analogs using alpha-glucosidase revealed that analogs introducing C-3-C-6 alkyl chains into an ammonium cation retained 20 % higher activity than the control cryoprotectants at the same concentration. In particular, the analog possessing triplicate n-butyl chains showed a profound effect. It allowed retention of enzyme activity to 95 % even after 100 freeze-thaw cycles, while addition of the control cryoprotectants decreased the activity to 10-20 %. The cryoprotective ability of betaine-type analogs can be applied not only to alpha-glucosidase but also other enzymes such as beta-glucosidase, alkaline phosphatase, lactose dehydrogenase, sulfatase, and horseradish peroxidase.Synthetic betaine-type metabolite analogs possess practicable cryoprotective ability for various enzymes, and are considerably superior to previously reported cryoprotectants.
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Enhanced Immunostimulating Activity of Lactobacilli-Mimicking Materials by Controlling Size Reviewed International journal
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 2015.8
Publisher：AMER CHEMICAL SOC
The design and synthesis of materials capable of activating the immune system in a safe manner is of great interest in immunology and related fields. Lactobacilli activate the innate immune system of a host when acting as probiotics. Here, we constructed lactobacilli-mimicking materials in which polysaccharide peptidoglycan complexes (PS PGs) derived from lactobacilli were covalently conjugated to the surfaces of polymeric microparticles with a wide variety of sizes, ranging from 200 nm to 3 mu m. The artificial lactobacilli successfully stimulated macrophages without cytotoxicity. Importantly, we found that the size of artificial lactobacilli strongly influenced their immunostimulating activities, and that artificial lactobacilli of 1 mu m exhibited 10-fold higher activity than natural lactobacilli. One major advantage of the artificial lactobacilli is facile control of size, which cannot be changed in natural lactobacilli. These findings provide new insights into the design of materials for immunology as well as the molecular biology of lactobacillus.
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Mechanistic study of unusual enzyme activation caused by addition of inert betaine-type metabolite and the analogs
Yuichi Nakagawa, Kazuya Koumoto
ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY 249 2015.3
Publisher：AMER CHEMICAL SOC
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Synthesis and lmmunestimulating Activity of Lactobacilli-Originated Polysaccharide-Polymeric Microparticle Conjugates Reviewed International journal
Koji Nagahama, Takayuki Kumano, Tsubasa Nakata, Hirokazu Tsuji, Kaoru Moriyama, Kan Shida, Koji Nomoto, Katsuyoshi Chiba, Kazuya Koumoto, Jun Matsui
LANGMUIR 31 ( 4 ) 1489 - 1495 2015.2
Publisher：AMER CHEMICAL SOC
The design and synthesis of biomaterials capable of activating the immune system are of interest in immunology-related fields because of their ability to tune up the immune defenses of the host. Lactobacilli are a major constituent of normal human indigenous flora, and some specific strains are known to activate the immune system of the host as probiotics. In this study, we first fabricated novel biohybrid materials in which lactobacilli (L. casei strain Shirota, LcS)-originated polysaccharide-peptidoglycan complexes (PS-PGs) are conjugated with polymeric microparticles (MPs). PS-PGs conjugated onto polymeric MPs surfaces bound its specific antibody, suggesting that PS-PGs kept their original molecular recognition ability. The PS-PGs-based hybrid MPs with an appropriate density of conjugated PS-PGs effectively induced high levels of IL-12 production from macrophages without cytotoxicity. These results suggest that LcS-originated PS-PGs could be available bio-originated materials for developing novel biomaterials capable of activating the immune system in a safe manner.
DOI： 10.1021/la5041757
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Cryoprotective ability of betaine-type metabolite analogs during freezing denaturation of enzymes Reviewed
Yuichi Nakagawa, Masahiro Sota, Kazuya Koumoto
Biotechnology Letters 37 1607 - 1613 2015
Joint Work
Authorship：Lead author
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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
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Cholesterol-appended b-(1,3)-D-glucan schizophyllan for antisense oligonucleotide delivery to enhance cellular uptake
甲元一也
Bull. Chem. Soc. Jpn. ( 78 ) 1821 - 1830 2005.11
Single Work
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Parallel vs. anti-parallel orientation in a curdlan/oligo(dA) complex as estimated by a FRET technique
甲元一也
Org. Biomol. Chem., ( 3 ) 2255 - 2261 2005.11
Single Work
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Competition between Polysaccharide/Polynucleotide Complexation vs. Polynucleotide Hybridization; Salt Concentration Dependence of the Reaction Direction
甲元一也
e-J. Surface Sci. Nanotech. ( 3 ) 30 - 37 2005.11
Single Work
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PEG-appended b-(1→3)-D-glucan schizophyllan to deliver antisense-oligonucleotides with avoiding lysosomal degradational of New Modification Technique for Linear Double-Stranded DNAs Using the Polysaccharide Schizophyllan
甲元一也
Biomaterials ( 26 ) 4866 - 4873 2005.11
Single Work
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Schizophyllan-Poly(N-isopropylacrylamide) Conjugate for Selective Recovery of Polynucleotides by Precipitation
甲元一也
Polym. J., ( 37 ) 177 - 185 2005.11
Single Work
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多糖・核酸複合体を用いた機能性高分子コンジュゲート −核酸医薬デリバリーへの挑戦−
甲元一也
高分子加工 ( 53 ) 561 - 568 2004.11
Single Work
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A Polysaccharide Carrier for Immunostimulatory CpG DNAs to Enhance Cytokine Secretion
甲元一也
J. Am. Chem. Soc. ( 126 ) 8372 - 8373 2004.11
Single Work
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Removal of the side-chain glucose groups from schizophyllan improves the thermal stability of the polycytidylic acid complex under the physiological conditions
甲元一也
Biopolymers ( 75 ) 403 - 411 2004.11
Single Work
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Schizophyllans carrying oligosaccharide appendages as potential candidates for cell-targeted antisense carrier
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Org. Biomol. Chem ( 2 ) 3091 - 3098 2004.11
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Proposal of New Modification Technique for Linear Double-Stranded DNAs Using the Polysaccharide Schizophyllan
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Bioorg. Med. Chem. Lett ( 14 ) 5655 - 5659 2004.11
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Chemically modified polysaccharide schizophyllan for antisense oligonucleotides delivery to enhance the cellular uptake efficiency
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Biochim. Biophys. Acta ( 1670 ) 91 - 104 2004.11
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Lactose-appended schizophyllan as a potential candidate for hepatocyte-targetted antisense carrier
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Chem. Commun 382 - 383 2004.11
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Protection of polynucleotides against nuclease-mediated hydrolysis by complexation with schizophyllan
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Biomaterials ( 25 ) 3109 - 3116 2004.11
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Antisense oligonucleotides bound in the polysaccharide complex and the enhanced antisense effect due to the low hydrolysis
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Biomaterials ( 25 ) 3117 - 3123 2004.11
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Long-Term Expression with Cationic Polymer Derived from a Natural Polysaccharide: Schizophyllan
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Bioconjugate Chem ( 15 ) 249 - 259 2004.11
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Polysaccharide/Polynucleotide Complexes Part 6: Complementary-Strand-Induced Release of Single-stranded DNA Bound in the Schizophyllan Complex
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Chemistry & Biodiversity ( 1 ) 520 - 529 2004.11
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Enhancement of antisense effect by reducing interactions between proteins and ODNs
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Bull. Chem. Soc. Jpn. ( 77 ) 1101 - 1110 2004.11
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First observation by Fluorescence Polarization of Complexation between mRNA and the Natural Polysaccharide Schizophyllan
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Chemistry & Biodiversity ( 1 ) 634 - 639 2004.11
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Molecular weight control of curdlan (b-1,3-glucan polysaccharide) provides unique polynucleotide binding properties
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Polym. J. ( 36 ) 380 - 385 2004.11
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Low Mw sulfated curdlan with improved water-solubility forms macromolecular complexes with polycytidylic acid
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Carbohydr. Res ( 339 ) 161 - 167 2004.11
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Microanalysis of Nucleic Acids Using the Limulus G Test
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Anal. Sci ( 19 ) 1567 - 1568 2003.11
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アンチセンス治療に向けた多糖系遺伝子キャリアー
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月刊BIOINDUSTRY 20 ( 10 ) 30 - 37 2003.11
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Polysaccharide-Polynucleotide Complexes Part 7. Hydrogen-ion and Salt Concentration Dependence of Complexation between Schizophyllan and Single-Stranded Homo RNAs
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Bioorg. Chem ( 31 ) 216 - 226 2003.11
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Supramolecular structure of a sugar-appended organogelator explored with synchrotron X-ray small angle scattering
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Langmuir, ( 19 ) 8211 - 8217 2003.11
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Polysaccharide-polynucleotide complexes Part 17. Solvent effects on conformational-transition of polydeoxyadenylic acid in the complex with schizophyllan
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Polym. J. ( 35 ) 714 - 720 2003.11
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Polysaccharide-polynucleotide Complexes (15): Thermal Stability of Schizophyllan(SPG)/Poly(C) Triple Strands is Controllable by the a-Amino Acid Modification
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Bioorg. Chem ( 31 ) 163 - 171 2003.11
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Molecular Design of “Super” Hydrogelators: Understanding the Gelation process of Azobenzene-Based Sugar Derivatives in Water
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Org. Lett., ( 4 ) 1423 - 1426 2002.11
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Chemical modification of curdlan: Characteristic complexation with polynucleotides by control of the molecular weight
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Polym. Prep 43 ( 2 ) 721 - 723 2002.11
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Novel DNA-polysaccharide triple helix and its application to a gene carrier
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Polym. Prep 43 ( 2 ) 691 - 692 2002.11
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Polysaccharide-polynucleotide Interaction (XI); Novel Separation System of RNAs by Using Schizophyllan-appended Column
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Chem. Lett. 1240 - 1241 2002.11
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Polysaccharide-Polynucleotide Complexes Part 12: Enhanced affinity for various polynucleotide chains by site-specific chemical modification of schizophyllan
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Perkin Trans. 1 2477 - 2484 2002.11
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Sol-gel phase transition induced by fiber-vesicle structural changes in sugar-based bolaamphiphiles
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Perkin Trans 2 1930 - 1936 2002.11
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Gel formation properties of a uracil-appended cholesterol gelator and cooperative effects of the complementary nucleobases
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Tetrahedron ( 58 ) 8863 - 8873 2002.11
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Polysaccharide-Polynucleotide Complexes Part 8. Cation Induced Complex Formation between Polyuridylic Acid and Schizophyllan
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Biopolymers ( 65 ) 1 - 9 2002.11
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Application of schizophyllan as a novel gene carrier
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Nucleic Acids Res. Supplement ( 1 ) 223 - 224 2001.11
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A novel technique to specifically separate RNAs by Schizophyllan
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Nucleic Acids Res. Supplement ( 1 ) 283 - 284 2001.11
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Chemical Modification of Curdlan to Induce an Interaction with Poly(C)
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Chem. Lett 908 - 909 2001.11
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Chemical modification of schizophyllan by introduction of a cationic charge into the side chain which enhances the thermal stability of schizophyllan/poly(C) complexes
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Chem. Commun 1962 - 1963 2001.11
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Organization of Nucleosides Supported by Boronic-Acid-Appended poly(L-Lysine): Creation of a Novel RNA Mimic
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Bull. Chem. Soc. Jpn ( 74 ) 1311 - 1317 2001.11
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Polysaccharide-Polynucleotide Complexes (IV): Anti-hydrolysis effect of the schizophyllan/poly(C) complex and the complex dissociation induced by amines
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Bioorg. Chem., ( 29 ) 178 - 185 2001.11
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Thermally induced conformational–transition of polydeoxyadenosine in the complex with schizophyllan and the base-length dependence of its stability
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Chem. Commun. 429 - 430 2001.11
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分子転写法による新素材の開発 –生体分子を超える分子認識材料開発を目指して-
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未来材料 1 ( 5 ) 35 - 41 2001.11
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TEM and SEM observations of super-structures constructed in organogel systems from a combination of boronic-acid-appended bola-amphiphiles with chiral diols
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Nanotechnology, ( 12 ) 25 - 31 2000.11
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Polysaccharide-Polynucleotide Complex (III): A novel interaction between the b-1,3-Glucan Family and the Single-Strand RNA: Poly(C)
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Chem. Lett 1242 - 1243 2000.11
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The First Example of Positive Allosterism in an Aqueous Saccharide-Binding System Designed on a Ce(IV) Bis(porphyrinate) Double Decker Scaffold
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Tetrahedron ( 56 ) 4717 - 4723 2000.11
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Colorimetric Sugar Sensing Method Useful in “Neutral” Aqueous Media
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Chem. Lett., 856 - 857 2000.11
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