Regulation of the H+/e− stoichiometry of cytochrome c oxidase from bovine heart by intramitochondrial ATP/ADP ratios

FEBS Letters

Frank, Viola¹  Kadenbach, Bernhard¹ 

[1] Fachbereich Chemie, Philipps-Universität, D-35032 Marburg, Germany

关键词: Proton translocation;    Cytochrome c oxidase;    ATP;    ADP;    H+/e− stoichiometry;    Tissue-specific regulation;   

DOI  :  10.1016/0014-5793(96)00096-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

This paper describes the effect of intramitochondrial ATP/ADP ratios on the H⁺/e⁻ stoichiometry of reconstituted cytochrome c oxidase (COX) from bovine heart. At 100% intraliposomal ATP the H⁺/e⁻ stoichiometry of the reconstituted enzyme is decreased to half of the value measured below 98% intraliposomal ATP (above 2% ADP), while it remains constant up to 100% ADP. The decrease is obtained with different COX preparations, independent of the absolute value of the H⁺/e⁻ stoichiometry. Decrease of H⁺/e⁻ stoichiometry is prevented by preincubation of the enzyme with a tissue-specific monoclonal antibody to subunit VIa-H (heart-type). Tissue-specific regulation of the efficiency of energy transduction in COX of muscle mitochondria could have a physilogical function in maintaining the body temperature at rest or sleep, i.e. at low ATP expenditure.

【 授权许可】

Unknown