Flow-force relationships in mitochondrial oxidative phosphorylation.
The rates of oxidation and phosphorylation in isolated rat-liver mitochondria have a steep dependence on the protonmotive force (delta mu H+) across the membrane. These experimentally observed relationships proved to be independent of the way in which delta mu H+ was varied. These results were obtained when the membrane potential (delta psi) was calculated from the distribution of K+ (in the presence of valinomycin). When triphenylmethylphosphonium (TPMP+) was used as a probe for delta psi, slightly different flow-force relationships were obtained. We conclude that unique relationships exist between delta mu H+ and the rates of oxidation and phosphorylation, and that under some conditions the behaviour of the probe TPMP+ is anomalous.
D000818:Animals; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D008930:Mitochondria, Liver / Q000378:metabolism*; D009861:Onium Compounds / Q000494:pharmacology; D010085:Oxidative Phosphorylation; D010101:Oxygen Consumption; D011188:Potassium / Q000378:metabolism; D051381:Rats; D014320:Triphenylmethyl Compounds / Q000494:pharmacology; D014634:Valinomycin / Q000494:pharmacology
D009861:Onium Compounds; D014320:Triphenylmethyl Compounds; C011561:triphenylmethylphosphonium; D014634:Valinomycin; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D011188:Potassium