title: Platelet Ca2+-activated, phospholipid-dependent protein kinase: evidence for proteolytic activation of the enzyme in cells treated with phospholipase C1.
abstract: Incubation of human platelets with C. perfringens phospholipase C caused an increase in soluble protein kinase activity assayed in the presence of EGTA, and a decrease in Ca2+/phospholipid-dependent protein kinase activity. Fractionation of extracts on DEAE-cellulose columns showed that phospholipase C treatment resulted in a new peak of protein kinase active in the presence of EGTA. On Sephadex G-100 chromatography this enzyme eluted as a single peak of protein kinase activity of MW about 50,000. An extract from untreated platelets eluted as a single peak of Ca2+/phospholipid-dependent protein kinase of MW about 77,000. It was concluded that phospholipase C treatment resulted in the proteolysis of this latter enzyme to the lower MW form.
mesh_terms: D001792:Blood Platelets / Q000201:enzymology*; D002118:Calcium / Q000494:pharmacology*; D004533:Egtazic Acid / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D008970:Molecular Weight; D010740:Phospholipases / Q000494:pharmacology*; D010743:Phospholipids / Q000494:pharmacology*; D011493:Protein Kinase C; D011494:Protein Kinases / Q000097:blood*; D010738:Type C Phospholipases / Q000494:pharmacology*
chemical_list: D010743:Phospholipids; D004533:Egtazic Acid; D011494:Protein Kinases; D011493:Protein Kinase C; D010740:Phospholipases; D010738:Type C Phospholipases; D002118:Calcium