Susceptibility of protein kinase C to oxidative inactivation: loss of both phosphotransferase activity and phorbol diester binding.
Exposure of protein kinase C to low concentrations of either N-chlorosuccinimide or H2O2 resulted in rapid and parallel loss of phosphotransferase activity and phorbol ester binding. This oxidative inactivation of protein kinase C also occurred in intact cells exposed to a low concentration of H2O2. With H2O2 treatment the rate of inactivation of protein kinase C in the cytosol of MCF-7 cells was rather slower than that which occurred in the cytosol of PYS cells. However, in both cell types, the oxidative inactivation of membrane-associated protein kinase C occurred rapidly in comparison to the enzyme in the cytosol. Prior treatment of cells with phorbol ester to induce membrane association (stabilization) of protein kinase C, followed by exposure to H2O2, resulted in increased inactivation of protein kinase C, suggesting that membrane association of protein kinase C increases its susceptibility to oxidative inactivation.
Gopalakrishna
R
R
Department of Pathology, School of Medicine, University of California, Los Angeles 90024.
Anderson
W B
WB
D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology; D003600:Cytosol / Q000201:enzymology; D004789:Enzyme Activation / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000494:pharmacology; D006878:Hydroxides / Q000378:metabolism; D017665:Hydroxyl Radical; D007700:Kinetics; D010084:Oxidation-Reduction; D015240:Phorbol 12,13-Dibutyrate; D010703:Phorbol Esters / Q000378:metabolism*; D010770:Phosphotransferases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011493:Protein Kinase C / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013388:Succinimides / Q000494:pharmacology
D006878:Hydroxides; D010703:Phorbol Esters; D013388:Succinimides; C015752:N-chlorosuccinimide; D017665:Hydroxyl Radical; D015240:Phorbol 12,13-Dibutyrate; D006861:Hydrogen Peroxide; D010770:Phosphotransferases; D011493:Protein Kinase C