Reaction mechanism of [FeFe] hydrogenases

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K21748
• Research Category: Fund for the Promotion of Joint International Research (Home-Returning Researcher Development Research)
• Allocation Type: Multi-year Fund
• Research Field: Biophysics
• Research Institution: Hokkaido University
• Principal Investigator: Ogata Hideaki 北海道大学, 低温科学研究所, 特任准教授 (30795935)
• Co-Investigator(Kenkyū-buntansha): Higuchi Yoshiki 兵庫県立大学, 生命理学研究科, 教授 (90183574)
• Project Period (FY): 2017 – 2019
• Keywords: 酵素 / ヒドロゲナーゼ / 反応機構 / フーリエ変換赤外分光 / 電気化学

Outline of Final Research Achievements

[FeFe] hydrogenases (an electron-bifurcating and a sensory types) have successfully been maturated with the chemically synthesized di-iron complexes. The catalytic activity of the electron-bifurcating [FeFe] hydrogenase showed the high catalytic activity similar to that of the standard [FeFe] hydrogneases. The results of the electron-bifurcating assay with ferredoxin and NADH suggested that one of the iron-sulfur clusters might be the electron bifurcating site. The sensory [FeFe] hydrogenase showed less activity than that of the standard hydrogenase enzyme. The electrochemical FTIR spectroscopic data indicated that the three distinct oxidation states could be assigned.

Academic Significance and Societal Importance of the Research Achievements

電子伝達体フェレドキシンとNADHを用いた電子伝達分岐反応から、HydAサブユニット中の鉄硫黄クラスターが分岐を制御していると提唱した。調節型[FeFe]ヒドロゲナーゼの活性は、触媒型ヒドロゲナーゼの活性能と比べ非常に低いことがわかった。このことから活性中心周辺のアミノ酸の重要性が明らかとなった。本研究で明らかとなった知見はヒドロゲナーゼを模した化学錯体の設計に重要な指針を与える。

Free Research Field

生物物理学