The substrate specificity of purified PKC-α, -β and -γ has been investigated. A series of synthetic peptides based upon the sequence surrounding serine-7 in glycogen synthase were generated and used to determine the basic residue requirements of these PKC isotypes. While PKC-α and -β are indistinguishable in their phosphorylation of these peptides, PKC-γ shows a distinct specificity profile for these synthetic substrates.
