Protein kinase C (PKC), a serine-and threonine-phosphorylating enzyme, is thought to play central roles in cellular signal transductions. 2 To clarify its physiological roles and to serve, potentially, as an important compound in anticancer therapies, a specific PKC inhibitor would be of great use. PKC has a catalytic site that phosphorylates substrate proteins and a regulatory site that controls its kinase activity. Since the catalytic site shares many features ...
