Cooperativity in inhibition of mitochondrial oxidative phosphorylation by adriamycin
Muhammed, H.; Kurup, C.K.
Indian Journal of Biochemistry and Biophysics 19(6): 388-393
1982
ISSN/ISBN: 0301-1208 PMID: 7184858 Document Number: 183749
Inhibition of oxidative phosphorylation in heart, liver and kidney mitochondria by adriamycin has been subjected to kinetic analysis based on the Hill equation. The non-linear nature of the Hill plots indicates that the drug interferes with 2 critical steps in oxidative phosphorylation. In the presence of dinitrophenol, which eliminates the regulatory effect of phosphorylation, the Hill plots become linear. Equilibrium binding revealed that the mitochondrial membranes possess high affinity binding sites for adriamycin. More binding sites are exposed in the presence of hexokinase which potentiates the inhibitory action of adriamycin.