THE MODE OF ACTION OF ANTIFUNGAL AGENTS : EFFECT OF PYRROLNITRIN ON MITOCHONDRIAL ELECTRON TRANSPORT

Abstract

Pyrrolnitrin preferentially inhibited the oxidation of NADH-linked substrates in monkey kidney cells, and in rat liver mitochondria (RLMw) and the oxidation of NADH by submitochondrial particles (SMP) of beef heart. The antibiotic inhibited the reduction of 2, 6-dichlorophenolindophenol and cytochrome c by NADH and by succinate, but it did not affect the flavins of NADH dehydrogenase and succinate dehydrogenase. Pyrrolnitrin probably blocked electron transfer between the dehydrogenases and the cytochrome components of the respiratory chain. The effect on the phosphorylation of ADP (RLMw) and energy transduction (SMP) as indicated by the fluorescence of 8-anilino-naphthalene-1-sulfonic acid were secondary. Reduced pyrrolnitrin had similar effects on respiration, but it was a less potent inhibitor.