Functional analysis and application studies of gut microbe-derived sulfoglycosidase and sulfated mucin in symbiosis

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K17820
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Functional biochemistry; Applied microbiology
• Research Institution: Kyoto University
• Principal Investigator: Katoh Toshihiko 京都大学, 生命科学研究科, 助教 (40724612)
• Research Collaborator: Maeshibu Takako
• Project Period (FY): 2017-04-01 – 2019-03-31
• Keywords: スルフォグリコシダーゼ / ビフィズス菌 / 糖質分解酵素 / ムチン / 硫酸化糖鎖

Outline of Final Research Achievements

Bifidobacterium bifidum, a beneficial gut microbe, expresses many membrane-surface glycan-degrading enzymes, although by which it degrades mucin glycoproteins secreted from intestine, the details of mucin degradation were remained unclear. Therefore, one of such membrane-surface glycan-degrading enzymes from B. bifidum, sulfoglycosidase BbhII, was characterized in this study. The study revealed that 1) details of BbhII mucin-degrading activity and bbhII gene response upon mucin in vitro, 2) x-ray crystallography of BbhII. These results help understanding about the mechanism how beneficial gut microbes adapt to intestinal habitat.

Free Research Field

応用微生物学

Academic Significance and Societal Importance of the Research Achievements

本研究成果によって、ヒト腸内細菌であるビフィズス菌に硫酸化糖鎖特異的に作用するスルフォグリコシダーゼが存在すること、および本酵素がムチン分解に関連することが明らかにされるとともに、本酵素の硫酸化糖鎖認識メカニズムが構造学的に世界で初めて明らかにされた点で学術的にも価値があると考えられる。本酵素の存在の提示よってヒト腸管から分泌されるムチン分子の腸内細菌叢の形成や定着への重要性がより一層強く示されることとなった。