Diacylglycerol effects on phosphatidylinositol-specific phospholipase C activity and vesicle fusion

Diacylglycerol increased the hydrolytic activity of phosphatidylinositol-sp ecific phospholipase C on large unilamellar vesicles containing 5-40% phosp hatidylinositol. Moreover, diacylglycerol increased the rate and extent of vesicle fusion (contents mixing) induced by the enzyme. Kinetic studies of intervesicular lipid mixing revealed that fusion was limited by the frequen cy of contacts involving two diacylglycerol-rich domains. (C) 2001 Federati on of European Biochemical Societies. Published by Elsevier Science B.V. Al l rights reserved.