Effect of ion-transporting antibiotics on the energy-linked reactions of submitochondrial particles

Abstract

The effects of ion-transporting antibiotics on the energy-linked reactions of submitochondrial particles were studied. It was found that valinomycin and nigericin in the presence of K + led to the release of the oligomycin-induced respiratory control, and to a virtually complete inhibition of the four energy-linked reactions: pyridine nucleotide transhydrogenation, BTB and ANS responses, and reversal of electron transfer. Valinomycin alone in the presence of K + did not release the oligomycin-induced control, but inhibited the energy-linked reactions by approximately 50%. Nigericin alone in the presence of K + stimulated the oligomycin-inhibited respiration by approximately 50%, but did not affect the energy-linked reactions. The results are discussed in terms of current hypotheses of energy coupling in oxidative and photosynthetic phosphorylation.