Purification of phosphoinositide-specific phospholipase C from a particulate fraction of bovine brain.
The coupling of various agonist receptors to the hydrolysis of phosphoinositides has generated much interest in the nature of the phospholipase C that is activated. Here we report the purification of a bovine brain phospholipase C derived from the particulate fraction. A 1000-fold purification was achieved by a combination of heparin-Sepharose, DEAE-cellulose and gel-permeation chromatography. The purified enzyme appears to be monomeric and under denaturing conditions shows a single staining major polypeptide of molecular mass 154 kDa in SDS gels. The enzyme is specific for phosphoinositides although it shows a marked preference for the polyphosphoinositides. With phosphatidylinositol 4,5-bisphosphate as substrate the enzyme expresses a specific activity of greater than 100 mumol min-1 mg-1. The phospholipase C is activated by Ca2+ (0.1-10 microM). The behaviour of this particulate enzyme is discussed in the context of a agonist-induced phosphatidylinositol hydrolysis.
Katan
M
M
Ludwig Institute for Cancer Research, University College, London, England.
Parker
P J
PJ
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002118:Calcium / Q000494:pharmacology; D002417:Cattle; D002845:Chromatography; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D004789:Enzyme Activation; D006868:Hydrolysis; D010716:Phosphatidylinositols / Q000302:isolation & purification*; D013379:Substrate Specificity; D010738:Type C Phospholipases / Q000302:isolation & purification*
D010716:Phosphatidylinositols; D010738:Type C Phospholipases; D002118:Calcium