Attempts to obtain electrons from water molecules by realizing the reversed reaction of enzymatic process

Research Project

Project/Area Number	26650031
Research Category	Grant-in-Aid for Challenging Exploratory Research
Allocation Type	Multi-year Fund
Research Field	Functional biochemistry
Research Institution	Kanazawa University
Principal Investigator	Takeshi Sakurai 金沢大学, 物質化学系, 教授 (90116038)
Project Period (FY)	2014-04-01 – 2016-03-31
Project Status	Completed (Fiscal Year 2015)
Budget Amount *help	¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000) Fiscal Year 2015: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000) Fiscal Year 2014: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Keywords	マルチ銅オキシダーゼ / 逆反応 / 酸素４電子還元 / 水の酸化 / タイプ１銅 / 三核銅部位 / プロテインエンジニアリング / 酵素機能 / 酸素発生
Outline of Final Research Achievements	Multicopepr oxidase is a class of enzymes to perform the four-electron reduction of dioxygen at the trinuclear copper center by utilizing electrons from substrates extracted at the type I copper center. The aim of this study is to realize the reverse reaction of this four-electron reduction of dioxygen. Our strategy to realize this attempt was to shift the oxidation-reduction potential of the type I copper center towards positive direction by performing mutations at the ligands to type I copper and/or amino acids located in the outer coordination spheres. Mutations on CueO and bilirubin oxidase were succeeded but we could not realize the reverse reaction to form dioxygen even utilizing a variety of electrode materials. We are trying to realize our aim by using other multicopper oxidases.