Acylation of 2-acyl-glycerophosphocholine in guinea-pig heart microsomal fractions.
Acyl-CoA:2-acyl-sn-glycero-3-phosphocholine (GPC) acyltransferase is required for the maintenance of the asymmetric distribution of saturated fatty acids at the C-1 position of phosphatidylcholine; however, this activity has been reported to be absent in cardiac tissue. In the present study a very active acyl-CoA:2-acyl-GPC activity was detected and characterized in guinea-pig heart microsomes (microsomal fractions); the mitochondria did not appear to possess this activity. The acyl-CoA specificity of the microsomal acyl-CoA:2-acyl-GPC acyltransferase was distinct from the corresponding acyl-CoA:1-acyl-GPC acyltransferase. These differences were due to the position of the fatty acid on the lysophospholipid rather than the composition of the fatty acids. The enzyme did not exhibit a distinct preference for saturated fatty acids, as might be expected. Our results suggest that, in the heart, control of the intracellular composition and concentration of acyl-CoAs by acyl-CoA hydrolase and acyl-CoA synthetase may play an important role in maintaining the asymmetric distribution of fatty acids in phosphatidylcholine.
Arthur
G
G
Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
D000215:Acylation; D000217:Acyltransferases / Q000378:metabolism*; D000818:Animals; D006168:Guinea Pigs; D008861:Microsomes / Q000201:enzymology*; D008929:Mitochondria, Heart / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology*
D000217:Acyltransferases; C031076:2-acylglycerophosphocholine acyltransferase