Studies on the proton pump mechanism of the terminal oxidase by time resolved analyses at the hydrogen atom level resolution

2016 Fiscal Year Final Research Report

• Project/Area Number: 26291033
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Biophysics
• Research Institution: University of Hyogo
• Principal Investigator: Yoshikawa Shinya 兵庫県立大学, 生命理学研究科, 名誉教授 (40068119)
• Co-Investigator(Renkei-kenkyūsha): ISHIMORI Koichiro 北海道大学, 大学院理学系研究院, 教授 (20192487) ; TATENO Masaru 兵庫県立大学, 大学院生命理学研究科, 教授 (40291926) ; SHINZAWA Kyoko (ITOH Kyoko) 兵庫県立大学, 大学院生命理学研究科, 准教授 (70206316) ; KUBO Minoru 独立行政法人理化学研究所, 城生体金属科学研究室, 研究員 (90392878) ; TAMADA Tarou 独立行政法人日本原子力研究開発機構, 量子ビーム応用研究部門, 研究主幹 (50391248) ; MISAKI Tomonori 兵庫県立大学, 大学院物質理学研究科, 助教 (00411786)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 呼吸鎖末端酸化酵素 / プロトンポンプ / 膜タンパク質 / ヘムタンパク質 / 時分割X線構造解析

Outline of Final Research Achievements

Cytochrome c oxidase, which is one of the most important enzymes for preserving the Life, reduces molecular oxygen (O2) coupled with proton pumping which creates the proton gradient for driving ATP synthesis by FoF1 ATPase. By using the X-ray free electron laser facility, we have succeeded in (i) determination of the O2 reduction site and (ii) showing that the pumping proton back leak is blocked by O2 binding to a copper ion site included in the O2 reduction site. The O2 reduction site structure has been yet to be determined for the last 50 years. The latter accomplishment together with the former set a mile stone for elucidation of the mechanism of this enzyme at the hydrogen atom level resolution which is a dream of most of Life Scientist.

Free Research Field

生物化学