The relationship between the bilayer to hexagonal phase transition temperature in membranes and protein kinase C activity.

A number of substances affect the activity of protein kinase C. Among uncharged and zwitterionic compounds, those which activate protein kinase C also lower the bilayer to hexagonal phase transition temperature of dielaidoylphosphatidylethanolamine while substances which inhibit protein kinase C raise this transition temperature. Using this criteria, we have identified 3 beta-chloro-5-cholestene, 5 beta-cholan-24-ol and eicosane as new protein kinase C activators and have shown that Z-Ser-Leu-NH2, Z-Gly-Leu-NH2, Z-Tyr-Leu-NH2, cyclosporin A and cholestan-3 beta, 5 alpha, 6 beta-triol are protein kinase C inhibitors.