characterization of glycoside hydrolase 134 family mannanase

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K07734
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Applied microbiology
• Research Institution: Meijo University
• Principal Investigator: Shimizu Motoyuki 名城大学, 農学部, 准教授 (20423535)
• Co-Investigator(Kenkyū-buntansha): 佐藤 育男 名古屋大学, 生命農学研究科, 助教 (70743102)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: β-1,4-mannanase / AoMan134 / β-mannan / GH 134 / mannnooligosaccharide / Aspergillus oryzae

Outline of Final Research Achievements

We investigated the enzymatic function and structure of β-1,4-mannanase AoMan134A from Aspergillus oryzae. Recombinant AoMan134A was prepared, and the reaction products from galactose-free β-mannan generated by the enzyme were analyzed. AoMan134A released mannobiose (M2), mannotriose (M3), and mannotetraose (M4) but not mannopentaose (M5) or higher manno-oligosaccharides when galactose-free β-mannan was the substrate. AoMan134A had high catalytic efficiency (kcat/Km) towards M6 compared with the endo-β-1,4-mannanase Man5C and notably converted M6 to M2, M3, and M4, with M3 being the predominant reaction product. We also revealed that AoMan134A had lyzozyme-like structure with two active-site amino acid residues.

Free Research Field

応用微生物学、酵素学

Academic Significance and Societal Importance of the Research Achievements

AoMan134Aは、熱安定性を有する既知のβ-マンナナーゼと同等もしくはそれ以上の高い熱安定性をもち、中性からアルカリ性においてpH 安定性を有していた。現在産業利用されている既存のβ-マンナナーゼと比較して、高い熱安定性および効率的なマンノオリゴ糖生産能を有していることから、AoMan134Aは機能性マンノオリゴ糖の生産に適していると考えられ、マンノオリゴ糖を含む（食品）産業での応用が期待できる。