Reduction of cytochrome b‐561 through the antimycin‐sensitive site of the ubiquinol‐cytochrome c 2 oxidoreductase complex of Rhodopseudomonas sphaeroides

FEBS Letters

Glaser, Elzbieta G.¹  Meinhardt, Steven W.¹  Crofts, Antony R.¹ 

[1] University of Illinois, Department of Physiology and Biophysics, 524 Burrill Hall, 407 S. Goodwin Avenue, Urbana, IL 6180 I. USA

关键词: Ubiquinol-cytochrome c2 oxidoreductase;    Antimycin-sensitivity;    Myxothiazol;    Electrogenic process;    Cytochrome b-561;    (Rps. sphaeroides);    Bchi;    bacteriochlorophyll;    Mops;    3-(Nmorpholino) propanesulfonic acid;    Hepps;    N-2-hydroxyethylpiperazine -N-2-propanesulfomc acid;    Cyt;    cytochrome;    FeS;    Rieske-type iron-sulfur center;    Q;    QH2;    ubiquinone;    ubiquinol;   

DOI  :  10.1016/0014-5793(84)80629-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Cytochrome b-561 of the ubiquinol-cytochrome c ₂ oxidoreductase complex of Rhodopseudomonas sphaeroides is reduced after flash illumination in the presence of myxothiazol in an antimycin-sensitive reaction. Flash-induced reduction was observed over the redox range in which cytochrome b-561 and the Q-pool are both oxidized before the flash. The extent of reduction increased with increasing pH, and was maximal at pH > 10.0 where the extent approached that observed in the presence of antimycin following a group of flashes. Reduction of cytochrome b-561 in the presence of myxothiazol showed a lag of ~ 1 ms after the flash, followed by reduction with (t ~ 6 ms; by analogy with the similar kinetics of the quinol oxidase site, we suggest that the rate is determined by collision with the QH₂ produced in the pool on flash excitation.

【 授权许可】

Unknown