[Effect of dibucaine on the association of protein kinase C with liposome].

The association of protein kinase C with membranes are thought to be a prerequisite for the activation of the enzyme. Dibucaine has been reported to inhibit the enzyme activity competitively with phosphatidylserine. We investigated the effect of dibucaine on the association of protein kinase C with liposome. Calcium and phorbol 12-myristate 13-acetate (PMA) independently and synergistically induced the association of rat brain protein kinase C with phosphatidylserine/phosphatidylcholine liposome. Although dibucaine inhibited the association induced by calcium alone, it did not affect the association induced by PMA alone. Dibucaine, however, inhibited the association which was induced synergistically by calcium and PMA. It was suggested that dibucaine did not always inhibit the association of protein kinase C with phospholipid membranes.