Localization of a ferricyanide‐reactive site of cytochrome b−c 1 complex, possibly of cytochrome b or ubisemiquinone, at the outer face of submitochondrial particles

FEBS Letters

Kunz, Wolfram S.²  Konstantinov, Alexander²  Tsofina, Liliya¹  Liberman, Efim A.¹ 

[1] Institute of Information Transmission Problems, Academy of Sciences of the USSR, Ermolova str. 19, Moscow, USSR;A.N. Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry, Moscow State University, Moscow 117234 USSR

关键词: Respiratory chain;    Q-cycle;    Cytochrome;    b Membrane potential;    Cytochrome;    b−c 1 site inhibitor;    Redox center topography;    NoHOQnO;    2-(n-nonyl)-4-hydroxyquinoline N-oxide;    PCB−;    phenyldicarbaundecaborane anion;    SMP;    submitochondrial particles;    Δψ;    transmembrane electric potential difference;   

DOI  :  10.1016/0014-5793(84)81137-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

When succinate oxidation by submitochondrial particles is blocked by antimycin, NoHOQnO or funiculosin, addition of ferricyanide restores oxygen uptake coupled to membrane potential generation. The effect of ferricyanide is abolished by mucidin or myxothiazol, as well as by KCN. The data strongly favor a cyclic redox loop mechanism in site 2 and show that either heme of the ferrous cytochrome b or ubisemiquinone formed in the QH₂-oxidizing center of complex b−c ₁ is accessible to ferricyanide at the outer (M) side of the submitochondrial particle membrane.

【 授权许可】

Unknown