お砂糖だけが「糖」ではありません。
植物は光合成によって空気中の二酸化炭素から糖を作り出します。植物が作る糖の中で、最も生産量の多いものが細胞壁です。植物細胞壁は年間生産量約1,500-2000億トンと言われており、地球上に最も多く存在するバイオマス資源として知られています。植物細胞壁は、空気中の二酸化炭素から作られたものですから、燃やしても地球温暖化ガスを増加させることはないため、地球環境に優しい原料です。
当研究室では、植物細胞壁の成分のうち、利用が敬遠されている「ヘミセルロース」という成分に焦点をあて、ファインケミカルや食品・化粧品素材、健康食品、生分解性プラスチック、植物生長促進剤等の広範な用途にヘミセルロースを利用するための技術を開発する研究を行っています。
主な研究内容
糖質関連酵素(CAZy)の構造機能相関の解析
ヘミセルロースは、複数の構成糖を含むことが特徴で、構成糖の種類・分岐構造が植物種や植物の生長段階・部位により異なるため、均質な素材を作りにくく、利用が困難です。
バイオ燃料の原料として期待されるセルロースはヘミセルロースに覆われているため、ヘミセルロースを除かなければセルロースを糖化することはできません。通常のバイオ燃料製造プロセスにおいては酸・熱を利用してヘミセルロースを完全分解して取り除く方法が行われていますが、この方法では、ヘミセルロース分解物を発酵原料として利用することしかできないため、ヘミセルロースの利用可能性を狭めています。また、ヘミセルロースはペントース(5炭糖)を主成分とするため、発酵には適していません。
そこで、当研究室では「酵素」を使ってヘミセルロースを分解します。酵素は、ある特定の構造のみを認識して、反応を触媒する分子であるため、極めて高い構造選択性を有しています。酵素の性質、立体構造を色々な視点から見ることで、ヘテロな構造をしたヘミセルロースから均質な素材を得ることが可能になります。
上に示したのは当研究室で研究に用いている放線菌の生産するキシラーゼの構造ですが、このキシラナーゼは酵素活性を持つ触媒ドメインと基質に結合する基質結合ドメインから構成されています。触媒ドメインは糖加水分解酵素に非常に多く見られる(β/α)8-バレル構造、基質結合ドメインは植物のレクチンと同じ構造をしていました。立体構造の情報をもとに基質特異性を決めているメカニズム、酵素の安定性のメカニズムなどについて調べています。
その他、数多くのヘミセルロース分解酵素や海藻多糖の分解酵素について、研究を行っています。
オリゴ糖の製造と機能の評価
性質の明らかになったヘミセルロース分解酵素を組合わせ、様々な構造のオリゴ糖を製造し、食品素材、健康食品、生分解性プラスチック、植物生長促進剤等の広範な用途におけるヘミセルロースの利用可能性を検証していきます。
最近の業績
Rikako Tsukida, Makoto Yoshida, and Satoshi Kaneko: Characterization of an α-L-arabinofuranosidase GH51 from the brown-rot fungus Gloeophyllum trabeum. J. Appl. Glycosci.., 70(1), xxx-XXX (2023).
Sosyu Tsutsui, Tomohiro Hatano, Ryo Funada, and Satoshi Kaneko: Microorganisms capable of producing polysaccharides from D-xylose. J. Appl. Glycosci.., 69(4), 83-89 (2022).
Ken-ji Yokoi, Sosyu Tsutsui, Gen-ya Arakawa, Masakazu Takaba, Koichi Fujii, and Satoshi Kaneko: Molecular and biochemical characteristics of inulosucrase InuBK from Alkalihalobacillus krulwichiae JCM 11691. Biosci. Biotechnol. Biochem.., 85(8), 1830-1838 (2021).
Zui Fujimoto, Koji Teramoto, Sosyu Tsutsui, and Satoshi Kaneko: Structure based analysis of substrate specificity of GH11 xylanase from Streptomyces olivaceoviridis E-86. Appl. Microbiol. Biotechnol.., 105, 1943-1952 (2021).
Koji Teramoto, Sosyu Tsutsui, Tomoko Sato, Zui Fujimoto, and Satoshi Kaneko: Substrate specificities of GH8, GH39, and GH52 β-xylosidases from Bacillus halodurans C-125 toward substituted xylooligosaccharides. Appl. Biochem. Biotechnol.., 193, 1042-1055 (2021).
Kaori Matsuyama, Naomi Kishine, Zui Fujimoto, Naoki Sunagawa, Toshihisa Kotake, Yoichi Tsumuraya, Masahiro Samejima, Kiyohiko Igarashi, and Satoshi Kaneko: Unique active site and subsite features in the arabinogalactan-degrading GH43 exo-β-1,3-galactanase from Phanerochaete chrysosporium. J. Biol. Chem.., 295 (52), 18539-18552 (2020).
Akihiko Nakamura, Daiki Ishiwata, Akasit Visootsat, Taku Uchiyama, Kenji Mizutani, Satoshi Kaneko, Takeshi Murata, Kiyohiko Igarashi, and Ryota Iino: Domain architecture divergence leads to functional divergence in binding and catalytic domains of bacterial and fungal cellobiohydrolases. J. Biol. Chem.., 295 (43), 14606-14617 (2020).
Taku Uchiyama, Takayuki Uchihashi, Akihiko Nakamura, Hiroki Watanabe, Satoshi Kaneko, Masahiro Samejima, and Kiyohiko Igarashi: Convergent evolution of processivity in bacterial and fungal cellulases. Proc. Natl. Acad. Sci. U.S.A.., in press (2020).
Kiyohiko Igarashi, Satoshi Kaneko, Motomitsu Kitaoka, and Masahiro Samejima: Effect of C-6 methylol groups on substrate recognition of glucose/xylose mixed oligosaccharides by cellobiose dehydrogenase from the basidiomycete Phanerochaete chrysosporium. J. Appl. Glycosci.., 67 (2), 51-58 (2020).
Sosyu Tsutsui, Kiyoshi Sakuragi, Kiyohiko Igarashi, Masahiro Samejima, Satoshi Kaneko: Evaluation of ammonia pretreatment for enzymatic hydrolysis of sugarcane bagasse to recover xylooligosaccharides. J. Appl. Glycosci.., 67 (1), 17-22 (2020).
Kiyotaka Fujita, Ayami Sakamoto, Satoshi Kaneko, Toshihisa Kotake, Yoichi Tsumuraya, and Kanefumi Kitahara: Degradive enzymes for type II arabinogalactan side chains in Bifidobacterium longum subsp. longum. Appl. Microbiol. Biotechnol., 103, 1299-1310 (2019).
Tsutomu Arai, Peter Biely, Iveta Uhliariková, Nobuaki Sato, Satoshi Makishima, Masahiro Mizuno, Kouichi Nozaki, Satoshi Kaneko, and Yoshihiko Amano: Structural characterization of hemicellulose released from corn cob in continuous flow type hydrothermal reactor. J. Biosci. Bioeng., 127,222-230 (2019).
Haruka Yagi, Ryo Takehara, Aika Tamaki, Koji Teramoto, Sosyu Tsutsui, Satoshi Kaneko: Functional characterization of the GH10 and GH11 xylanases from Streptomyces olivaceoviridis E-86 provide insights into the advantage of GH11 xylanase in catalyzing biomass degradation. J. Appl. Glycosci., 66, 29-35 (2019).
Yayun Wang, Makiko Sakka, Haruka Yagi, Satoshi Kaneko, Hirotaka Katsuzaki, Emi Kunitake, Tetsuya Kimura, Kazuo Sakka: Ruminiclostridium josui Abf62A-Axe6A: A tri-functional xylanolytic enzyme exhibiting α-L-arabinofuranosidase, endoxylanase, and acetylxylan esterase activities. Enzyme Microb. Technol.., 117, 1-8 (2018).
Kentarou Suzuki, Mari Michikawa, Haruna Sato, Kei Kamino, Wataru Ogasawara, Shinya Fushinobu, and Satoshi Kaneko : Purification, cloning, functional expression, structure, and characterization of thermostable β-mannanase from Talaromyces trachyspermus and its efficiency in mannooligosaccharide production from coffee wastes. J. Appl. Glycosci., 65, 13-21 (2018).
Ryuichiro Suzuki, Zui Fujimoto, Satoshi Kaneko, Tsunemi Hasegawa, and Atsushi Kuno : Enhanced azidolysis by the formation of stable Ser–His catalytic dyad in a glycoside hydrolase family 10 xylanase mutant. J. Appl. Glycosci. 65, 1-8 (2018).
Tomoko Maehara, Haruka Yagi, Tomoko Sato, Mayumi Ohnishi-Kameyama, Zui Fujimoto, Kei Kamino, Yoshiaki Kitamura, Franz St. John, Katsuro Yaoi, and Satoshi Kaneko : Characterization of a GH30 glucuronoxylan specific xylanase from Streptomyces turgidiscabies C56. Appl. Environ. Microbiol., 84, e01850-17 (2017).
Yoshimi Yoshihisa, Kaori Yaguchi, Satoshi Kaneko, Yoichi Tsumuraya, Toshihisa Kotake : Properties of two fungal endo-β-1,3-galactanases and their synergistic action with an exo-β-1,3-galactanase in degrading arabinogalactan-proteins. Carbohydr. Res., 453-454, 26-35 (2017).
Haruka Yagi, Tomoko Maehara, Tsuyoshi Tanaka, Ryo Takehara, Koji Teramoto, Katsuro Yaoi, and Satoshi Kaneko : A GH67 α-glucuronidase from Bacillus halodulans C-125 critically discriminate 4-O-Methyl group of glucuronic acid in aldooligosaccharides. J. Appl. Glycosci., 64(4), 115-121 (2017).
Chiemi Imaizumi, Harumi Tomatsu, Kiminari Kitazawa, Yoshihisa Yoshimi, Seiji Shibano, Kaoru Kikuchi, Masatoshi Yamaguchi, Satoshi Kaneko, Yoichi Tsumuraya, and Toshihisa Kotake : Heterologous expression and characterization of an Arabidopsis β-L-arabinopyranosidase and α-D-galactosidases acting on β-L-arabinopyranosyl residues. J. Exp. Bot., 68(16), 4651-4661 (2017).
Tomohiko Matsuzawa, Satoshi Kaneko, Naomi Kishine, Zui Fujimoto, Katsuro Yaoi : Crystal structure of metagenomicβ-xylosidase/α-L-arabinofuranosidase activated by calcium. J. Biochem. 162(3), 173-181 (2017).
Yoshihisa Yoshimi, Yumi Sugawara, Chiaki Hori, Kiyohiko Igarashi, Satoshi Kaneko, Naoshi Dohmae, Yoichi Tsumuraya, and Toshihisa Kotake : A protease/peptidase from culture medium of Flammulina velutipes that acts on arabinogalactan-protein. Biosci. Biotechnol. Biochem. 81(3), 475-481 (2017).
Riki Shiroma, Yuan Li, Jeung-yil Park, Long Wu, Satoshi Kaneko, Tomoyuki Takai, Mitsuru Gau, Masakazu Ike, and Ken Tokuyasu : Evaluation of two-sets of sorghum bagasse samples as the feedstock for fermentable sugar recovery via the Calcium-Capturing-by Carbonation (CaCCO) process. J. Appl. Glycosci., 63, 77-85 (2016).
Tomohiko Matsuzawa, Satoshi Kaneko, and Katsuro Yaoi : Improvement of thermostability and activity of Trichoderma reesei endo-xylanase Xyn III on insoluble substrates. Appl. Microbiol. Biotechnol., 100, 8043-8051 (2016).
Akihiko Nakamura, Takuya Ishida, Katsuhiro Kusaka, Taro Yamada, ShinyaFushinobu, Ichiro Tanaka, Satoshi Kaneko, Kazunori Ohta, Hiroaki Tanaka, Koji Inaka, Yoshiki Higuchi, Nobuo Niimura, Masahiro Samejima and Kiyohiko Igarashi : “Newton’s cradle” proton relay with amide-imide tautomerization in inverting cellulase catalysis visualized by neutron crystallography. Science Advances, 1(7) e1500263 (2015).
Tomohiko Matsuzawa, Satoshi Kaneko, and Katsuro Yaoi : Screening, identification and characterization of a GH43 family β-xylosidase/α-arabinofuranosidase from a compost microbial metagenome. Appl. Microb. Biotechnol., 99(21), 8943-8954 (2015).
Adiphol Dilokpimol, Christian Peter Poulsen, György Vereb, Satoshi Kaneko, Alexander Schulz, and Naomi Geshi : Galactosyltransferases from Arabidopsis thaliana in the biosynthesis of type II arabinogalactan: molecular interaction enhances enzyme activity. BMC Plant Biology, 14(1), 90-103 (2014).
Tomoko Maehara, Zui Fujimoto, Hitomi Ichinose Mari Michikawa, Koichi Harazono, and Satoshi Kaneko : Crystal structure and characterization of the glycoside hydrolase family 62 α-L-arabinofuranosidase from Streptomyces coelicolor. J. Biol. Chem., 289(11), 7962-7972 (2014).
Takafumi Kasumi, Sumiko Mori, Satoshi Kaneko, Hitoshi Matsumoto, Yosuke Kobayashi, Yoshiyuki Koyama : Characterization of mannose isomerase from a cellulolytic actinobacteria Thermobifida fusca MBL10003. J. Appl. Glycosci. 61(1), 21-25 (2014).
Tomoko Maehara, Koji Takabatake, and Satoshi Kaneko : Expression of Arabidopsis thaliana xylose isomerase gene and the effect on ethanol production in Flammulina velutipes. Fungal Biol., 117(11-12), 776-782 (2013).
Akihiko Nakamura, Takuya Ishida, Shinya Fushinobu, Katsuhiro Kusaka, Ichiro Tanaka, Koji Inaka, Yoshiki Higuchi, Mika Masaki, Kazunori Ohta, Satoshi Kaneko, Nobuo Niimura, Kiyohiko Igarashi and Masahiro Samajima : Phase diagram-guided method for growth of a large crystal of glycoside hydrolase family 45 inverting cellulase suitable for neutron structural analysis. Journal of Synchrotron Radiation, 20(Pt6), 859-863 (2013).
Naomi Geshi, Jorunn N. Johansen, Adiphol Dilokpimol, AuréliaRolland, Katia Belcram, Stéphane Verger, Toshihisa Kotake, Yoichi Tsumuraya, Satoshi Kaneko, Theodora Tryfona, Paul Dupree, Henrik V. Scheller, Herman Höfte, and Gregory Mouille: A galactosyltransferase acting on arabinogalactan protein glycans is essential for embryo development in Arabidopsis. Plant J. 76 (1), 128-137 (2013).
Zui Fujimoto, Adam Jackson, Mari Michikawa, Tomoko Maehara, Mitsuru Momma, Bernard Henrissat, Harry J. Gilbert, and Satoshi Kaneko : The structure of a Streptomyces avermitilis α-L-rhamnosidase reveals a novel carbohydrate-binding module CBM67 within the six-domain arrangement. J. Biol. Chem., 288 (17), 12376-12385 (2013).
Hitomi Ichinose, Zui Fujimoto, and Satoshi Kaneko : Characterization of a α-L-rhamnosidase from Streptomyces avermitilis. Biosci. Biotechnol. Biochem., 77, 213-216 (2013).
Tomoko Maehara, Hitomi Ichinose, Takanori Furukawa, Wataru Ogasawara, Koji Takabatake, and Satoshi Kaneko : Ethanol production from high cellulose concentration by the basidiomycete fungus Flammulina velutipes, Fungal Biol., 117, 220-226 (2013).
Kiminari Kitazawa, Theodora Tryfona, Yoshihisa Yoshimi, Yoshihiro Hayashi, Susumu Kawauchi, Liudmil Antonov, Hiroshi Tanaka, Takashi Takahashi, Satoshi Kaneko, Paul Dupree, Yoichi Tsumuraya, and Toshihisa Kotake : β-Galactosyl Yariv reagent binds to β-1,3-galactan of arabinogalactan-protein. Plant Physiol., 161(3), 1117-1126 (2013).
Takafumi Kasumi, Sumiko Mori, Satoshi Kaneko, and Yoshiyuki Koyama : Molecular cloning and characterization of D-xylose isomerase from a novel actinobacteria, Thermobifida fusca MBL10003. J. Appl. Glycosci., 59, 43-46 (2012).
Hitomi Ichinose, Yuko Araki, Mari Michikawa, Koichi Harazono, Katsuro Yaoi, Shuichi Karita, and Satoshi Kaneko : Characterization of an endo-processive type xyloglucanase having β-1,4-glucan binding module and an endo-type xyloglucanase from Streptomyces avermitilis. Appl. Environ. Microbiol., 78, 7939-7945 (2012).
Mari Michikawa, Hitomi Ichinose, Mitsuru Momma, Peter Biely, Seino Jongkees, Makoto Yoshida, Toshihisa Kotake, Yoichi Tsumuraya, Stephen G. Withers, Zui Fujimoto, and Satoshi Kaneko : Structural and biochemical characterization of glycoside hydrolase family 79 β-glucuronidase from Acidobacterium capsulatum. J. Biol. Chem., 287, 14069-14077 (2012).
Hitomi Ichinose, Shaghik Diertavitian, Zui Fujimoto, Atsushi Kuno, Leila Lo Leggio, and Satoshi Kaneko : Structure-based engineering of glucose specificity in a family 10 xylanase from Streptomyces olivaceoviridis E-86. Process Biochem., 47, 358-365 (2012).
Tomoko Maehara, Tomoyuki Takai, Hiroaki Ishihara, Makoto Yoshida, Kiyoharu Fukuda, Mitsuru Gau, and Satoshi Kaneko : Effect of lime pretreatment of brown mid-rib sorghums. Biosci. Biotechnol. Biochem., 75, 2415-2417 (2011).
Toshihisa Kotake, Naohiro Hirata, Yuta Degi, Maki Ishiguro, Kiminari Kitazawa, Ryohei Takata, Hitomi Ichinose, Satoshi Kaneko, Kiyohiko Igarashi, Masahiro Samejima, and Yoichi Tsumuraya : Endo-β-1,3-galactanase from winter mushroom Flammulina velutipes. J. Biol. Chem., 286, 27848 -27854 (2011).
Mária Matulová, Peter Capek, Satoshi Kaneko, Luciano Navarini, Furio Suggi Liverani : Structure of arabinogalactan oligosaccharides derived from arabinogalactan-protein of Coffea arabica instant coffee powder, Carbohydr. Res., 346, 1029-1036 (2011).
Alan Cartmell, Lauren McKee, Maria J. Pena, Johan Larsbrink, Harry Brumer, Hitomi Ichinose, Satoshi Kaneko, Richard J. Lewis, Anders Vikso-Nielsen, Harry J. Gilbert, and Jon Marles-Wright : The structure and function of an arabinan-specific α-1,2-arabinofuranosidase identified from screening the activities of bacterial GH43 glycoside hydrolases. J. Biol. Chem., 286, 15483-15495 (2011).
Esther M. Göllner, Hitomi Ichinose, Satoshi Kaneko, Wolfgang Blaschek, and Birgit Classen : An arabinogalactan-protein from whole grain of Avena sativa L. belongs to the wattle-blossom type of arabinogalactan-proteins. Journal of Cereal Science 53, 244-249 (2011).
Zui Fujimoto, Hitomi Ichinose, Peter Biely and Satoshi Kaneko : Crystallization and preliminary crystallographic analysis of glycoside hydrolase family 115 α-glucruonidase from Streptomyces pristinaespiralis, Acta Crystallogr. F, F67, 68-71 (2011).