Electrogenic proton exchange between cytochrome a 3 active center and M‐aqueous phase

FEBS Letters

Konstantinov, Alexander¹  Andreev, Igor M.¹  Vygodina, Tatiana¹ 

[1]A.N. Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry, Moscow State University, Moscow 119899, USSR

关键词: Cytochrome-c oxidase;    Proteoliposome;    Proton well;    Cyanide binding;    Proton pump;    Heme-linked ionizable group;   

DOI  :  10.1016/0014-5793(86)80692-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The rate of cyanide binding with the oxidized cytochrome-c oxidase in proteoliposomes is controlled by ionization of a protein group with pK~6.7, the ligand reacting with the protonated enzyme only [(1983) Bioorg. Chem. (USSR) 9,216-227]. As shown here, the kinetics of cyanide binding depends on the pH inside the proteoliposomes. The reaction rate is affected by the electrical potential difference across the proteoliposome membranes as if the a ₃-linked ionizable group exchanged H⁺ with the proteoliposome interior electrogenically. The data corroborate a hypothesis on the existence of a proton well communicating cytochrome oxidase O₂-reducing center with the M-aqueous phase.

【 授权许可】

Unknown