Inhibition of oxidative phosphorylation by aminosidine and other antibiotics, in rat liver mitochondria

Several antibiotics, belonging to the class of basic polysaccharides, such as streptomycin, kanamycin, neomycin, and aminosidine, inhibit the phosphorylation coupled to ketoglutarate oxidation in rat liver mitochondria. The effect of aminosidine has been compared to that of its N-methaneosulphonate derivatives and of the products obtained by methanolysis. Results show that the uncoupling activity depends both on the presence of free amino groups and on the moelcular complexity of the antibiotic. The mechanism of the uncoupling effect of aminosidine is different from that of dinitrophenol.