Effects of triphenylsulphonium ions on mitochondria. Inhibition of adenosine triphosphatase activity

Abstract

Triphenylsulfonium ions inhibit ox heart mitochondrial oxidative phosphorylation and ATP activity. The site of action is on the soluble F1 ATPase component. Triphenylsulfonium ions also inhibit electron transfer in the NAD-cytochrome b region of the respiratory chain. In both types of inhibition, triphenylsulfonium ions are effective at low concentrations, half-maximal inhibition being produced by a concentration of about 20-30 .mu.M. These effects resemble the effects of alkylguanidines on mitochondria and are discussed in relation to the effects of alkylguanidines and other lipophilic cations such as ethidium and dibenzyldimethylammonium ions. A modification of the purification procedure for the soluble mitochondrial ATPase is described, which yields a preparation with a higher specific activity and showing fewer bands in gel electrophoresis.