Analyses of inhibitory effects of Inhibitory factor-1 on human ATP-synthase.

2014 Fiscal Year Final Research Report

• Project/Area Number: 24570149
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Functional biochemistry
• Research Institution: The University of Tokyo (2014); Tokyo Institute of Technology (2012-2013)
• Principal Investigator: SUZUKI Toshiharu 東京大学, 工学(系)研究科(研究院), 主幹研究員 (60618809)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: ATPase / F1-ATPase / single molecule analysis / ATP

Outline of Final Research Achievements

Firstly, I analyzed rotary catalysis mechanism of human F1-ATPase by single molecule analyses. The rotation scheme revealed was that ATP-binding, Pi-releasing and ATP-hydrolysis steps of the ATP-hydrolysis turnover occur at 0, 65 and 90 deg, which was different from bacterial one and enables us to explain the functional state of crystal structures of bovine F1 so far reported. Then, inhibitory factor-1 (IF1) was shown to prevent the rotation at 90 deg, and the inhibited state was removed only by forced rotation of F1 with magnetic tweezer at the direction of ATP-synthesis : F1 was broken when forced rotation at ATP-hydrolysis direction. These results support and explain earlier findings from crystal structures and biochemical analysis that IF1 blocks only ATP-hydrolysis reaction by preventing an elementary step of ATP-hydrolysis by preventing rotation. These results would provide important clues to understand the regulatory mechanism of IF1 for future applied purposes.

Free Research Field

機能生物学