Antimycin A causes a biphasic suppression of the light-induced membrane potential generation in Rhodospirillum rubrum and Rhodopseudomonas sphaeroides chromatophores incubated anaerobically. The first phase is observed at low antibiotic concentrations and is apparently due to its action as a cyclic electron transfer inhibitor. The second phase is manifested at concentrations which are greater than 1-2 μM and is due to uncoupling that may be connected with an antibiotic-induced dissipation of the electrochemical H+gradient across the chromatophore membrane. The inhibitory effect of anti-mycin added at low concentrations under aerobic conditions is removed by succinate to a large extent. It is expected that the electrogenic cyclic redox chain in the bacterial chromatophores incubated under conditions of continuous illumination may function at two regimes: (1) as a complete chain involving all the redox components, and (2) as a shortened chain involving only the P-870 photoreaction center, ubiquinone and cytochrome c2. © 1979.
Remennikov, V. G., & Samuilov, V. D. (1979). Two regimens of electrogenic cyclic redox chain operation in chromatophores of non-sulfur purple bacteria A study using antimycin A. BBA - Bioenergetics, 548(2), 216–223. https://doi.org/10.1016/0005-2728(79)90130-0