Purification and characterisation of bovine brain protein kinase C isotypes α, β and γ

Several polyclonal antisera specific for each of the protein kinase C isotypes α, β1, β2 and γ have been generated and used to monitor the purification and subseqenct separation of these polypeptides. A simple protocol has been developed for the efficient co‐purification of these isotypes from bovine brain. The separation of the α, β1, β2 and γ isotypes has been monitored using the antibodies and pools containing pure α, β1, and γ forms have been produced. These isotypes have been characterised for activator dependence and substrate specificity. The results. indicate that while the isotypes have similar requirements for magnesium, calcium, ATP and phosphatidylserine, they differ in their dependence on phorbol esters and diacylglycerols. The isotypes also differ in their range of substrate specificities. The implications of these results are discussed.