title: Function of phospholipids on the regulatory properties of solubilized and membrane-bound sn-glycerol-3-phosphate acyltransferase of Escherichia coli.
abstract: Glycerophosphate acyltransferase (acyl-CoA:sn-glycerol-3-phosphate O-acyltransferase, EC 2.3.1.15) solubilized from Escherichia coli membranes was highly activated by phosphatidylglycerol. Phosphatidylethanolamine, cardiolipin and 1,2-diacyl-sn-glycerol 3-phosphate showed no effect. The Km of the enzyme for sn-glycerol 3-phosphate was increased 20-fold by solubilization. The value could not be restored by the addition of phospholipids. Temperature-sensitive regulation of the synthesis of either 1-palmitoyl- or cis-vaccenoyl-sn-glycerol 3-phosphate by the solubilized enzyme was identical with that by the membrane-bound enzyme in vivo and in vitro. The proportion of the molecular species of 1-acyl-sn-glycerol 3-phosphate varied when the ratios of palmitoyl-CoA and cis-vaccenoyl-CoA were changed, but changes in the sn-glycerol 3-phosphate concentration had no effect on selective acylation by both the solubilized and membrane-bound enzymes.
mesh_terms: D000217:Acyltransferases / Q000378:metabolism*; D002308:Cardiolipins / Q000494:pharmacology; D003065:Coenzyme A / Q000031:analogs & derivatives / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004926:Escherichia coli / Q000201:enzymology*; D005992:Glycerol-3-Phosphate O-Acyltransferase / Q000378:metabolism*; D007700:Kinetics; D008566:Membranes / Q000201:enzymology; D009829:Oleic Acids / Q000494:pharmacology; D010171:Palmitoyl Coenzyme A / Q000494:pharmacology; D010714:Phosphatidylethanolamines / Q000494:pharmacology; D010715:Phosphatidylglycerols / Q000494:pharmacology; D010743:Phospholipids / Q000494:pharmacology*; D012995:Solubility; D013696:Temperature
chemical_list: D002308:Cardiolipins; D009829:Oleic Acids; D010714:Phosphatidylethanolamines; D010715:Phosphatidylglycerols; D010743:Phospholipids; D010171:Palmitoyl Coenzyme A; D000217:Acyltransferases; D005992:Glycerol-3-Phosphate O-Acyltransferase; D003065:Coenzyme A