Regulation of the fatty acid composition of alkyl ether phospholipid in Ehrlich ascites tumor cells. The substrate specificities of 1-O-alkylglycerol 3-phosphate and 1-O-alkylglycero-3-phosphocholine acyltransferases.
Activity for the acylation of 1-O-alkyl-GP was found in the microsomes of Ehrlich ascites tumor cells. The reaction product was shown to be 1-O-alkyl-2-acyl-GP by identifying the acetolysis product as 1-O-alkyl-2-acyl-3-acetylglycerol. The acyl transfer activity to 1-O-alkyl-GP was significantly lower than that to 1-acyl-GP. The substrate specificity of 1-O-alkyl-GP acyltransferase was rather broad as regards thiol esters. Similar specificity was observed with 1-acyl-GP acyltransferase. In contrast to these acyltransferase systems, the 1-acyl- and 1-O-alkyl-GPC acyltransferases were specific for polyunsaturated fatty acyl-CoA's. Since a high percentage of polyunsaturated fatty acid and a little palmitic acid were located at the 2-position of 1-O-alkyl-2-acyl-GPC(E), the observed specificities for acyl-COA's of these acyltransferase systems can be considered in relation to the fatty acid composition at the 2-position of 1-O-alkyl-2-acyl-GPC(E) in the cells.
D000217:Acyltransferases / Q000378:metabolism*; D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000201:enzymology*; D005227:Fatty Acids; D005992:Glycerol-3-Phosphate O-Acyltransferase / Q000378:metabolism*; D007700:Kinetics; D051379:Mice; D010743:Phospholipids / Q000096:biosynthesis*; D013379:Substrate Specificity
D005227:Fatty Acids; D010743:Phospholipids; D000217:Acyltransferases; D005992:Glycerol-3-Phosphate O-Acyltransferase