The inhibition of oxidative phosphorylation

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Abstract
The enzymes catalyzing the esterification of inorganic phosphate coincident with the oxidation of glutamate were found to be localized in the mitochondrial fraction of liver and kidney. Phosphate esterification coupled with fatty acid oxidation was demonstrated in prepns. of rat liver mitochondria. The depression of oxidative phosphorylation by dinitrophenol (DNP) was confirmed using a number of substrates. Two metabolic products of DNP were found to be without influence on oxidative phosphorylation, which was markedly inhibited, however, by low concns. of a number of dyestuffs and also by 1,11-diamidinoundecane. The degree of stimulation by DNP of the oxidation of glutamate by kidney particles deficient in inorganic phosphate and/or adenine nucleotide was strongly dependent upon the presence of fluoride in the suspension medium. In general, substances which depressed oxidative phosphorylation also "replaced" inorganic phosphate and/or adenine nucleotide in this system. Acetate oxidation catalyzed by kidney particles was inhibited by substances which disrupt the linkage between oxidation and phosphorylation. The inhibition of acetate oxidation by DNP is considerably diminished in the presence of fluoride.