Lecithin:retinol acyltransferase in retinal pigment epithelial microsomes.
Microsomal preparations from retinal pigment epithelium carry out phosphatidylcholine synthesis upon incubation with 1-palmitoyllysophosphatidylcholine and fatty acyl-CoA. Phosphatidylcholine synthesized in situ in this manner is an acyl donor for retinyl ester synthesis, demonstrating the existence of lecithin:retinol acyltransferase. Although acyl transfer to retinol is from the 1-position of phosphatidylcholine, the fatty acid in the 2-position is important in substrate recognition. The finding of this novel enzyme activity in retinal pigment epithelial microsomes suggests that phosphatidylcholine is the endogenous acyl donor in CoA-independent retinol esterification observed in these preparations.
Saari
J C
JC
Department of Ophthalmology, School of Medicine, University of Washington, Seattle 98195.
Bredberg
D L
DL
D000217:Acyltransferases / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D007700:Kinetics; D008244:Lysophosphatidylcholines / Q000302:isolation & purification / Q000378:metabolism; D008861:Microsomes / Q000201:enzymology*; D010713:Phosphatidylcholines / Q000096:biosynthesis / Q000302:isolation & purification; D010857:Pigment Epithelium of Eye / Q000201:enzymology*; D013379:Substrate Specificity
D008244:Lysophosphatidylcholines; D010713:Phosphatidylcholines; D000217:Acyltransferases; C056942:lecithin-retinol acyltransferase