食品総合研究所

酵素研究ユニット

役割

酵素は、私たちが気がつかないうちに身近で使用されています。大半の缶飲料の表示には、「ブドウ糖果糖混液」とありますが、これはデンプンに酵素を作用させて製造した甘味料です。現在では、砂糖消費の3分の1が、このブドウ糖果糖混液に置き換わっています。ブドウ糖果糖混液の製造で使用されている酵素は、40年ほど前に世界に先駆け、我々の酵素研究ユニットで発見されたものです。この他、酵素は洗濯用洗剤や医薬品などにも使われています。 私たちの酵素研究ユニットでは食品製造技術に役立てることを目的として、新しい酵素を探す研究と、酵素の性質を改良する研究をしています。特に、酵素の性質を改良する研究では、遺伝子組換え技術を活用し分子レベルで酵素を改良しています。

 

主な研究テーマ

  1. 酵素の改変技術の開発

  2. 特性の改良された酵素を作り出すために、遺伝子操作技術を用いた分子レベルでの酵素改良法の開発を行っています。
  • 食品素材を製造するための酵素技術の開発
    酵素を利用して、例えば甘味料・調味料などの種々の食品素材が製造されています。食品製造技術に役立てることを目的として、新しい酵素を探す研究、酵素の性質を改良する研究、酵素を利用した製造技術に関する研究を行っています。
    従来技術である酵素生産菌のスクリーニングや、バイオインフォマティクス・酵素の立体構造解析などの最新技術を駆使して酵素技術を開発しています。
    食品素材を製造するための酵素技術の開発
  1. 身体に良いオリゴ糖を製造するための酵素の特性解明

  2. 新規オリゴ糖を合成する酵素として、ホスホリラーゼを中心とした種々の糖質関連酵素の研究を行っています。
  • ビフィズス菌の新規な糖代謝系の発見
    ビフィズス菌から新規な糖代謝系を発見し、その特性からビフィズス菌増殖因子と予想される人乳中に含まれるオリゴ糖構造を特定しました。このオリゴ糖を工業的に作ることが可能になれば、機能性食品として利用されることが期待できます。
    ビフィズス菌の新規な糖代謝系の発見ビフィズス菌に見いだされた新規な糖代謝経路により、ビフィズス菌の腸内生息の理由が説明された。また、人乳中に含まれるビフィズス因子がラクトNビオースIであることが推定された。

メンバー

ユニット長
北岡 本光(きたおか もとみつ)

主任研究員
伊藤 康博 (いとう やすひろ)/博士(農学)/専門:遺伝学、分子生物学

 

主要成果

  • A. Gotoh, T. Katoh, Y. Sugiyama, S. Kurihara, Y. Honda, H. Sakurama, T. Kambe, H. Ashida, M. Kitaoka, K. Yamamoto, and T. Katayama:Novel substrate specificities of two lacto-N-biosidases towards β-linked galacto-N-biose-containing oligosaccharides of globo H, Gb5, and GA1. Carbohydrate Research, 408, 18-24 (2015).
  • W. Saburi, Y. Tanaka, H. Muto, S. Inoue, R. Odaka, M. Nishimoto, M. Kitaoka, and H. Mori: Functional reassignment of Cellvibrio vulgaris EpiA to cellobiose 2-epimerase and an evaluation of the biochemical functions of the 4-O-β-d-mannosyl-d-glucose phosphorylase-like protein, UnkA. Bioscience, Biotechnology and Biochemistry, 79 (6), 969-977 (2015).
  • K. Abe, M. Nakajima, M. Kitaoka, H. Toyoizumi, Y. Takahashi, N. Sugimoto, H. Nakai, H. Taguchi: Large-scale preparation of 1,2-β-glucan using 1,2-β-oligoglucan phosphorylase. Journal of Applied Glycoscience, 62 (2), 47-52 (2015).
  • M. Sato, T. Arakawa, Y.-W. Nam, M. Nishimoto, M. Kitaoka, and S. Fushinobu: Open-close structural change upon ligand binding and two magnesium ions required for the catalysis of N-acetylhexosamine 1-kinase. Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics, 1854 (5), 333-340 (2015).
  • Y. Liu, M. Nishimoto, and M. Kitaoka: Facile enzymatic synthesis of sugar 1-phosphates as substrates for phosphorylases using anomeric kinases. Carbohydrate Research, 401, 1-4 (2015).
  • K. Chiku, T. Nihira, E. Suzuki, M. Nishimoto, M. Kitaoka, K.-i. Ohtsubo, and H. Nakai: Discovery of two β-1,2-mannoside phosphorylases showing different chain-length specificities from Thermoanaerobacter sp. X-514. PLoS One, 9 (12), e114882 (2014).
  • A. H. Viborg, F. Fredslund, T. Katayama, S. K. Nielsen, B. Svensson, M. Kitaoka, L. Lo Leggio, and M. Abou Hachem: A β1-6/β1-3 galactosidase from Bifidobacterium animalis subsp. lactis Bl-04 gives insight into sub-specificities of β-galactoside catabolism within Bifidobacterium. Molecular Microbiology, 94 (5), 1024-1040 (2014).
  • T. Nihira, F. Miyajima, K. Chiku, M. Nishimoto, M. Kitaoka, K.-i. Ohtsubo, and H. Nakai: One pot enzymatic production of nigerose from common sugar resources employing nigerose phosphorylase. Journal of Applied Glycoscience, 61 (3), 75-80 (2014).
  • K. K. Touhara, T. Nihira, M. Kitaoka, H. Nakai, and S. Fushinobu: Structural basis for reversible phosphorolysis and hydrolysis reactions of 2-O-α-glucosylglycerol phosphorylase. The Journal of Biological Chemistry, 289 (26), 18067-18075 (2014).
  • N. Jaito, W. Saburi, R. Odaka, Y. Kido, K. Hamura, M. Nishimoto, M. Kitaoka, H. Matsui, and H. Mori: Characterization of a thermophilic 4-O-β-D-mannosyl-D-glucose phosphorylase from Rhodothermus marinus. Bioscience, Biotechnology and Biochemistry, 78 (2), 263-270 (2014).
  • T. Nihira, M. Nishimoto, H. Nakai, K.-i. Ohtsubo, and M. Kitaoka: Characterization of two α-1,3-glucoside phosphorylases from Clostridium phytofermentans. Journal of Applied Glycoscience, 61 (2), 59-66 (2014).
  • M. Nakajima, H. Toyoizumi, K. Abe, H. Nakai, H. Taguchi, and M. Kitaoka: 1,2-β-Oligoglucan phosphorylase from Listeria innocua. PLoS One, 9 (3), e92353 (2014).
  • A. H. Viborg, T. Katayama, M. Abou Hachem, M. C. F. Andersen, M. Nishimoto, M. H. Clausen, T. Urashima, B. Svensson, and M. Kitaoka: Distinct substrate specificities of three glycoside hydrolase family 42 β-galactosidases from Bifidobacterium longum subsp. infantis ATCC 15697. Glycobiology, 24 (2), 208-216 (2014).
  • Y. Ogawa, K. Noda, S. Kimura, M. Kitaoka, and M. Wada: Facile preparation of highly crystalline lamellae of (1→3)-β-D-glucan using an extract of Euglena gracilis. International Journal of Biological Macromolecules, 64, 415-419 (2014).
  • T. Nihira, Y. Saito, K.-i. Ohtsubo, H. Nakai, and M. Kitaoka: 2-O-α-D-Glucosylglycerol phosphorylase from Bacillus selenitireducens MLS10 possessing hydrolytic activity on β-D-glucose 1-phosphate. PLoS One, 9 (1), e86548 (2014).
  • T. Nihira, Y. Saito, M. Nishimoto, M. Kitaoka, K. Igarashi, K.-i. Ohtsubo, and H. Nakai: Discovery of cellobionic acid phosphorylase in cellulolytic bacteria and fungi. FEBS Letters, 587 (21), 3556-3561 (2013).
  • T. Nihira, Y. Saito, K. Chiku, M. Kitaoka, K.-i. Ohtsubo, and H. Nakai: Potassium ion-dependent trehalose phosphorylase from halophilic Bacillus selenitireducens MLS10. FEBS Letters, 587 (21), 3382-3386 (2013).
  • Y. Koyama, M. Hidaka, M. Nishimoto, and M. Kitaoka: Directed evolution to enhance thermostability of galacto-N-biose/lacto-N-biose I phosphorylase. Protein Engineering, Design & Selection, 26 (11), 755-761 (2013).
  • T. Nihira, E. Suzuki, M. Kitaoka, M. Nishimoto, K.-i. Ohtsubo, and H. Nakai: Discovery of β-1,4-D-mannosyl-N-acetyl-D-glucosamine phosphorylase involved in the metabolism of N-glycans. The Journal of Biological Chemistry, 288 (38), 27366-27374 (2013).
  • H. Sakurama, M. Kiyohara, J. Wada, Y. Honda, M. Yamaguchi, S. Fukiya, A. Yokota, H. Ashida, H. Kumagai, M. Kitaoka, K. Yamamoto, and T. Katayama: Lacto-N-biosidase encoded by a novel gene of Bifidobacterium longum subspecies longum shows unique substrate specificity and requires a designated chaperon for its active expression. The Journal of Biological Chemistry, 288 (35), 25194-25206 (2013).
  • T. Miyazaki, M. Ichikawa, G. Yokoi, M. Kitaoka, H. Mori, Y. Kitano, A. Nishikawa, and T. Tonozuka: Structure of a bacterial glycoside hydrolase family 63 enzyme in complex with its glycosynthase product, and insights into the substrate specificity. The FEBS Journal, 280 (18), 4560-4571 (2013).
  • Y. Honda, M. Nishimoto, T. Katayama, and M. Kitaoka: Characterization of the cytosolic β-N-acetylglucosaminidase from Bifidobacterium longum subsp. longum. Journal of Applied Glycosience, 60 (3), 141-146 (2013).
  • T. Nihira, E. Suzuki, M. Kitaoka, M. Nishimoto, K.-i. Ohtsubo, and H. Nakai: Colorimetric quantification of α-D-mannose 1-phosphate. Journal of Applied Glycosience, 60 (2), 137-139 (2013).
  • T. Satoh, T. Odamaki, M. Namura, T. Shimizu, K. Iwatsuki, M. Kitaoka, M. Nishimoto, and J. Xiao: In vitro comparative evaluation of the impact of lacto-N-biose I, a major building block of human milk oligosaccharides, on the fecal microbiota of formula-fed infants. Anaerobe, 19, 50-57 (2013).
  • T. Nihira, Y. Saito, M. Kitaoka, M. Nishimoto, K.-i. Otsubo, and H. Nakai: Characterization of a laminaribiose phosphorylase from Acholeplasma laidlawii PG-8A and production of 1,3-β-D-glucosyl disaccharides. Carbohydrate Research, 361, 46-54 (2012).
  • T. Nihira, Y. Saito, M. Kitaoka, K.-i. Otsubo, and H. Nakai: Identification of Bacillus selenitireducens MLS10 maltose phosphorylase possessing synthetic ability for branched α-D-glucosyl trisaccharides.” Carbohydrate Research, 360, 25-30 (2012).
  • T. Ohnuma, T. Fukuda, S. Dozen, Y. Honda, M. Kitaoka, and T. Fukamizo: A glycosynthase derived from a family GH19 chitinase from the moss Bryum coronatum. Biochemical Journal, 444, 437-443 (2012).
  • H. Sakurama, S. Fushinobu, M. Hidaka, E. Yoshida, Y. Honda, H. Ashida, M. Kitaoka, H. Kumagai, K. Yamamoto, and T. Katayama: 1,3-1,4-α-L-Fucosynthase that specifically introduces Lewis a/x antigens into type-1/2 chains. The Journal of Biological Chemistry, 287, 16709-16719 (2012).
  • M. Goto, Y. Takano-Ishikawa, M. Nishimoto, and M. Kitaoka: In vitro effect of lacto-N-biose I on the antigen-specific immune responses of naïve splenocytes. Bioscience of Microbiota and Food Health, 31, 47–50 (2012).
  • M. Kitaoka, Y. Matsuoka, K. Mori, M. Nishimoto, and K. Hayashi: Characterization of a bacterial laminaribiose phosphorylase. Bioscience, Biotechnology and Biochemistry, 76 (2), 343-348 (2012).
  • T. Nihira, H. Nakai, K. Chiku, and M. Kitaoka: Discovery of nigerose phosphorylase from Clostridium phytofermentans. Applied Microbiology and Biotechnology, 93 (4), 1513-1522 (2012).
  • T. Nihira, H. Nakai, and M. Kitaoka: 3-O-α-D-Glucopyranosyl-L-rhamnose phosphorylase from Clostridium phytofermentans. Carbohydrate Research, 350, 94-97 (2012).
  • E. Yoshida, H. Sakurama, M. Kiyohara, M. Nakajima, M. Kitaoka, H. Ashida, J. Hirose, T. Katayama, K. Yamamoto, and H. Kumagai: Bifidobacterium longum subsp. infantis uses two different β-galactosidases for selectively degrading type-1 and type-2 human milk oligosaccharides. Glycobiology, 22 (3), 361-368 (2012).
  • M. Kiyohara, T. Nakatomi, S. Kurihara, S. Fushinobu, H. Suzuki, T. Tanaka, S-i Shoda, M. Kitaoka, T. Katayama, K. Yamamoto, and H. Ashida: An α-N-acetylgalactosaminidase from infant-associated bifidobacteria belonging to a novel glycoside hydrolase family 129 is implicated in an alternative mucin degradation pathway. The Journal of Biological Chemistry, 287 (1), 693-700 (2012).
  • M. Nishimoto, M. Hidaka, M. Nakaijima, S. Fushinobu, and M. Kitaoka: Identification of amino acid residues determining substrate preference of 1,3-β-galactosyl-N-acetylhexosamine phosphorylase. Journal of Molecular Catalysis B-Enzymatic, 74 (1-2), 97-102 (2012).
  • M. Kitaoka, T. Takahashi, Y. Li, and K. Hayashi: Self-transferring product inhibition observed during the hydrolysis of aryl-β-glucopyranosides by a β-glucosidase from Agrobacterium tumefaciens. Journal of Applied Glycoscience, 58 (4), 129-132 (2011).
  • S. Asakuma, E. Hatakeyama, T. Urashima, E. Yoshida, T. Katayama, K. Yamamoto, H. Kumagai, H. Ashida, J. Hirose, and M. Kitaoka: Physiology of the consumption of human milk oligosaccharides by infant-gut associated bifidobacteria. The Journal of Biological Chemistry, 286 (40), 34583-34592 (2011).
  • K. Inoue, M. Nishimoto, and M. Kitaoka: One-pot enzymatic production of 2-acetamide-2-deoxy-D-galactose (GalNAc) from 2-acetamide-2-deoxy-D-glucose (GlcNAc). Carbohydrate Research, 346 (15), 2432-2436 (2011).
  • B. Li, T. Nihira, H. Nakai, M. Nishimoto, and M. Kitaoka: An enzymatic colorimetric quantification of orthophosphate.” Journal of Applied Glycoscience, 58 (3), 125‒127 (2011).
  • M. Nishimoto, A. Kobayashi, Y. Honda, M. Kitaoka, and K. Hayashi: p-Nitrophenyl β-glycosides of β-1, 4-gluco/xylo-disaccharides for the characterization of subsites in endo-xylanases. Journal of Applied Glycoscience, 58 (3), 115‒118 (2011).
  • M. Miwa, T. Horimoto, M. Kiyohara, T. Katayama, M. Kitaoka, H. Ashida, and K. Yamamoto: Cooperation of β-galactosidase and β-N-acetylhexosaminidase from bifidobacteria in assimilation of human milk oligosaccharides with type-2 structure. Glycobiology, 20 (11), 1402-1409 (2010).
  • M. Nakajima, M. Nishimoto, and M. Kitaoka: Practical preparation of D-galactosyl-β1→4-L-rhamnose employing combined action of phosphorylases. Bioscience, Biotechnology and Biochemistry, 74 (8), 1652-1655 (2010).
  • K. Chiku, M. Nishimoto, and M. Kitaoka: Thermal decomposition of β-D-galactopyranosyl-(1→3)-2-acetamido-2-deoxy-D-hexopyranoses under neutral conditions. Carbohydrate Research, 345 (13), 1901-1908 (2010).
  • M. Hidaka, S. Fushinobu, Y. Honda, T. Wakagi, H. Shoun, and M. Kitaoka: Structural explanation for the acquisition of glycosynthase activity. The Journal of Biochemistry, 147 (2), 237-244 (2010).
  • M. Nakajima, M. Nishimoto, and M. Kitaoka: Characterization of D-galactosyl-β1→4-L-rhamnose phosphorylase from Opitutus terrae. Enzyme and Microbial Technology, 46 (3-4), 315-319 (2010).
  • J.-z. Xiao, S. Takahashi, M. Nishimoto, T. Odamaki, T. Yaeshima, K. Iwatsuki, and M. Kitaoka: Distribution of in vitro fermentation ability of lacto-N-biose I, the major building block of human milk oligosaccharides, in bifidobacterial strains. Applied and Environmental Microbiology, 76 (1), 54-59 (2010).