The major endogenous bovine brain protein kinase C inhibitor is a heat-labile protein.
A crude cytosolic fraction prepared from bovine brain contained protein kinase C, as shown by immunoblotting, but its activity was undetectable, suggesting the presence of interfering factors. Phosphatase, ATPase and protease activities did not account for the absence of detectable protein kinase C activity. The major contributing factor was found to be a heat-labile protein which was separated from the kinase by ion-exchange chromatography. The contribution to the total inhibitory activity of heat-stable proteins was relatively minor, suggesting that they may not function physiologically as protein kinase C inhibitors.
Fraser
E D
ED
MRC Group in Signal Transduction, Faculty of Medicine, University of Calgary, Alberta, Canada.
Walsh
M P
MP
D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000201:enzymology*; D002417:Cattle; D002852:Chromatography, Ion Exchange; D003600:Cytosol / Q000201:enzymology; D006358:Hot Temperature; D009419:Nerve Tissue Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors* / Q000302:isolation & purification
D009419:Nerve Tissue Proteins; D011493:Protein Kinase C