Two‐electron reduction of cytochrome c oxidase triggers a conformational transition

FEBS Letters

Scholes, Charles P.¹  Malmström, Bo G.¹ 

[1] Department of Biochemistry and Biophysics, University of Göteborg and Chalmers University of Technology, S-412 96 Göteborg, Sweden

关键词: Cytochrome oxidase;    Cyanide binding;    Redox-linked conformation;    Proton pump;   

DOI  :  10.1016/0014-5793(86)81197-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The slow increase of a cyanide-induced optical change at 437 nm following rapid cyanide inhibition of cytochrome oxidase has been followed as a function of the number of electrons donated from ferrocytochrome c to cytochrome a and Cu _a . The initial rate of optical change is a parabolic function of this number. The results have been analyzed in terms of a model where addition of electrons causes a conformational transition allowing rapid cyanide binding. The binding is followed by a slow intramolecular reaction responsible for the optical change. The analysis demonstrates that only molecules with both cytochrome a and Cu _a reduced can undergo the conformational change, which is suggested to be involved in the proton-pump mechanism of the oxidase.

【 授权许可】

Unknown