Flow-force relationships in mitochondrial oxidative phosphorylation

AbstractThe rates of oxidation and phosphorylation in isolated rat-liver mitochondria have a steep dependence on the protonmotive force (Δ≈smh) across the membrane. These experimentally observed relationships proved to be independent of the way in which δ≈gmh was varied. These results were obtained when the membrane potential (ΔΨ) was calculated from the distribution of K+ (in the presence of valinomycin). When triphenyl-methylphosphonium (TPMP+) was used as a probe for ΔΨ, slightly different flow-force relationships were obtained. We conclude that unique relationships exist between Δ≈smh + and the rates of oxidation and phosphorylation, and that under some conditions the behaviour of the probe TPMP+ is anomalous