Two distinct quinone‐modulated modes of antimycin‐sensitive cytochrome b reduction in the cytochrome bc1 complex
- 10 December 1984
- journal article
- Published by Wiley in FEBS Letters
- Vol. 178 (2) , 343-350
- https://doi.org/10.1016/0014-5793(84)80630-4
Abstract
Reduction of cytochrome b-560 (analogous to cyt b-562 of mitochondria) via an antimycin-sensitive route has been revealed in chromatophores of the photosynthetic bacterium, Rhodopseudomonas sphaeroides Ga. Indeed, the results suggest that two reductive mechanisms can be operative. One is consistent with the idea that the quinol generated at the reaction center QB site enters the Q pool and, via the Qc site, equilibrates with cytochrome b-560. The other reductive mode circumvents redox equilibrium with the pool; we consider that this could result from a direct encounter of the reaction center with the bc 1 complex perhaps involving a direct QB-QC site interaction. This latter reaction is suppressed by occupancy of the QC site, not only by antimycin but by ubiquinol and ubiquinone.Keywords
This publication has 35 references indexed in Scilit:
- Electron and proton transfers through quinones and cytochrome bc complexesBiochimica et Biophysica Acta (BBA) - Reviews on Bioenergetics, 1984
- The electrochemical domain of photosynthesisBiochimica et Biophysica Acta (BBA) - Reviews on Bioenergetics, 1983
- The site and mechanism of action of myxothiazol as an inhibitor of electron transfer in Rhodopseudomonas sphaeroidesFEBS Letters, 1982
- Complete inhibition of electron transfer from ubiquinol to cytochrome b by the combined action of antimycin and myxothiazolFEBS Letters, 1981
- Function of the iron-sulfur protein of the cytochrome b-c1 segment in electron-transfer and energy-conserving reactions of the mitochondrial respiratory chainBiochimica et Biophysica Acta (BBA) - Reviews on Bioenergetics, 1981
- The recognition and redox properties of a component, possibly a quinone, which determines electron transfer rate in ubiquinone‐cytochrome c oxidoreductase of mitochondriaFEBS Letters, 1981
- Possible molecular mechanisms of the protonmotive function of cytochrome systemsJournal of Theoretical Biology, 1976
- Protonmotive redox mechanism of the cytochrome b‐c1 complex in the respiratory chain: Protonmotive ubiquinone cycleFEBS Letters, 1975
- The different cytochrome b components in the respiratory chain of animal mitochondria and their role in electron transport and energy conservationBiochimica et Biophysica Acta (BBA) - Reviews on Bioenergetics, 1973
- The mechanism of action of the respiratory inhibitor, antimycinBiochimica et Biophysica Acta (BBA) - Reviews on Bioenergetics, 1973