N-Acylation of dog heart ethanolamine phospholipids by transacylase activity.
Radioactive N-acylethanolamine phospholipids were produced in dog heart homogenates incubated with acyl-labeled phosphatidylcholine in the presence of 5 mM Ca2+ and Triton X-100. 70-80% of the label in the N-acylethanolamine phospholipids was recovered in the N-acyl groups and most of the remainder was in the 1-O-acyl groups. Incubations with 1,2-dipalmitoylPC and 1-palmitoyl-2-linoleoylPC labeled in either the 1-O-acyl or 2-O-acyl moiety showed the predominant utilization of the acyl groups at the sn-1 position, indicating transacylation by phospholipase A1 (or lysophospholipase) activity. It is suggested that intramolecular transacylation from 1-O-acyl to N-acyl groups of phosphatidylethanolamine also occurred to some extent, thus providing a free primary hydroxy group as an additional acyl acceptor for the transacylation reaction.
D000215:Acylation; D000217:Acyltransferases / Q000378:metabolism*; D000818:Animals; D002250:Carbon Radioisotopes; D004285:Dogs; D066298:In Vitro Techniques; D007553:Isotope Labeling; D008245:Lysophospholipase / Q000378:metabolism; D009206:Myocardium / Q000201:enzymology*; D010713:Phosphatidylcholines / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000096:biosynthesis*; D010741:Phospholipases A / Q000378:metabolism; D054466:Phospholipases A1
D002250:Carbon Radioisotopes; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D000217:Acyltransferases; D010741:Phospholipases A; D054466:Phospholipases A1; D008245:Lysophospholipase