Partial characterization of protein kinase C from an insect cell line.
The characteristics of protein kinase C (EC 2.7.1.37) from an insect cell line (Choristoneura fumiferana) have been described. DEAE-cellulose chromatography produced a major peak of activity which eluted at 0.04-0.055 M NaCl. The enzyme was sensitive to phosphatidylserine in the presence of calcium. Phorbol 12-myristate 13-acetate (PMA) in nanomolar concentrations stimulated protein kinase C activity 8-fold over basal levels and reduced the enzymes requirement for Ca2+. The enzyme had a Ka of 10 nM for PMA. Diacylglycerols tested included diolein, dilinolein, diarachidonin, oleoyl-acetyl-glycerol, dioctonoyl-sn-glycerol, dipalmitin and distearin. A 2.5- to 3-fold activation was obtained in the presence of 26 microM diolein, 40 microM oleoyl-acetyl-glycerol and 46 microM dioctonoyl-sn-glycerol. The enzyme activity was sensitive to the inhibitor H-7 and 50% inhibition was achieved at a concentration of 52 microM H-7. Phosphatidylinositol enhanced enzyme activity in the absence of phosphatidylserine but phosphatidylethanolamine had no effect.
Gupta
J
J
Department of Biology, University of Waterloo, Ont., Canada.
Downer
R G
RG
D000818:Animals; D002460:Cell Line; D002850:Chromatography, Gel; D004075:Diglycerides / Q000378:metabolism; D004789:Enzyme Activation; D007915:Lepidoptera; D011493:Protein Kinase C / Q000378:metabolism*; D013379:Substrate Specificity; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D004075:Diglycerides; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate