Elucidation of inhibitor-resistance mechanism of Na+-pumping NADH-ubiquinone oxidoreductase from Vibrio cholera

Research Project

Project/Area Number	18H02147
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Review Section	Basic Section 38040:Bioorganic chemistry-related
Research Institution	Kyoto University
Principal Investigator	MIYOSHI HIDETO 京都大学, 農学研究科, 教授 (20190829)
Project Period (FY)	2018-04-01 – 2021-03-31
Project Status	Completed (Fiscal Year 2020)
Budget Amount *help	¥17,160,000 (Direct Cost: ¥13,200,000、Indirect Cost: ¥3,960,000) Fiscal Year 2020: ¥5,460,000 (Direct Cost: ¥4,200,000、Indirect Cost: ¥1,260,000) Fiscal Year 2019: ¥5,720,000 (Direct Cost: ¥4,400,000、Indirect Cost: ¥1,320,000) Fiscal Year 2018: ¥5,980,000 (Direct Cost: ¥4,600,000、Indirect Cost: ¥1,380,000)
Keywords	呼吸鎖酵素 / Na+-NQR / コレラ菌 / 抗菌剤 / コロルミシン / NADH脱水素酵素 / ユビキノン / 生体エネルギー / Na+-輸送性NADH-キノン酸化還元酵素 / 薬剤耐性 / NADH-キノン酸化還元酵素
Outline of Final Research Achievements	Na+-pumping NADH-ubiquinone oxidoreductase (Na+-NQR) is an essential respiratory enzyme of many pathogenic bacteria such as Vibrio cholerae, and hence, a promising target of antibiotics. Natural product korormicin is a selective inhibitor of Na+-NQR, which binds to the N-terminal region of the Nqr-B subunit. We recently demonstrated that korormicin-resistance of Na+-NQR may be closely related to conformational changes of the N-terminal region. To elucidate the relationship between the conformational changes of the N-terminal region and the acquired resistance against korormicin, we investigated the chemical method that enables us to introduce a functional molecule probe to the N-terminal region. Based on protein-ligand affinity-driven NAS chemistry, we succeeded in pinpoint chemical modification of the N-terminal region.
Academic Significance and Societal Importance of the Research Achievements	飲食店などでの病原性細菌に由来する食中毒が時々報道されるものの、コレラ菌による大規模な感染症は日本ではもはや深刻ではなくなった。しかし、発展途上国では地域的流行が散発しており、依然として人命に関わる深刻な感染症である。そのため、Na+-NQRを標的分子とする選択的殺菌剤の開発に向けた基盤技術の構築は、極めて重要な研究課題である。また、薬剤耐性菌の出現が深刻な問題となっている現在、Na+-NQRのような新しい創薬標的を継続的に研究する意義は大きい。