Isoenzyme patterns of protein kinase C and a phospholipid-dependent but Ca2+-inhibited enzyme fraction in the crude extracts of different tissues

AbstractWe compared the protein kinase C isoenzyme patterns of crude extracts of rabbit brain, cerebellum, spleen, thymus and human and pig granulocytes. The isoenzymes were fractionated by hydroxyapatite chromatography and the protein kinase C activity was determined with a synthetic oligopeptide substrate. In the extracts of several tissues we also observed an enzyme fraction which was activated by phosphatidylserine+diacylglycerol but inhibited by Ca2+