Acylation of endogenous phospholipids and added lysoderivatives by rat liver plasma membranes.
Phospholipid acyltransferase activities of plasma membranes have been investigated with various acyl-CoA thioesters (palmitoyl, stearoyl, oleoyl, linoleoyl and arachidonoyl) with and without added lysoderivatives. Different patterns of incorporation were observed for each acyl-CoA into endogenous phosphatidylcholine and phosphatidylethanolamine. The turnover rates calculated with tracer amounts of 10 microM acyl-CoA thioesters were five times faster for the polyunsaturated than for the saturated acyl moieties of phosphatidylethanolamine and phosphatidylcholine. Arachidonoyl-CoA was the best acyl donor at low concentrations and the maximal turnover rate was observed at about 25 microM. No saturation appeared at up to 100 microM linoleoyl-CoA. Linoleoyl-CoA transacylase acylated the lyso-compounds in the following order: lysophosphatidylcholine greater than lysophosphatidylserine and lysophosphatidylinositol, while lysophosphatidylethanolamine inhibited linoleate incorporation into the phosphatidylethanolamine itself. Linoleoyl-CoA transacylation was not affected by the fatty acyl moiety at the 1-position of the lysophosphatidylcholine. The results support the view that the plasma membrane acyltransferase activity might contribute to the formation of bile phosphatidylcholines.
D000215:Acylation; D000217:Acyltransferases / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism*; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism*; D008244:Lysophosphatidylcholines / Q000378:metabolism; D008246:Lysophospholipids; D008297:Male; D010713:Phosphatidylcholines / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism; D010716:Phosphatidylinositols / Q000378:metabolism; D010718:Phosphatidylserines / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*; D051381:Rats
D008244:Lysophosphatidylcholines; D008246:Lysophospholipids; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010716:Phosphatidylinositols; D010718:Phosphatidylserines; D010743:Phospholipids; C008301:lysophosphatidylethanolamine; C025449:lysophosphatidylinositol; C025059:lysophosphatidylserine; D000217:Acyltransferases; C025450:linoleoyl-CoA acyltransferase