A lecithin:retinol acyltransferase activity in human and rat liver.
This report demonstrates that exogenous phosphatidylcholine will serve as an acyl donor for the esterification of retinol complexed to cellular retinol-binding protein (CRBP) by human and rat liver microsomal preparations. The retinyl ester synthases utilized phosphatidylcholine but had little or no ability to transfer acyl groups from lysophosphatidylcholine, phosphatidyl-ethanolamine, or phosphatidic acid to retinol-CRBP. The human and rat activities also demonstrated positional selectivity as only the fatty acyl group at the sn-1 position of phosphatidylcholine was transferred. This in vitro activity may have considerable physiological importance since the fatty acyl composition at the sn-1 position of phosphatidylcholine is remarkably similar to the hepatic retinyl esters observed in vivo.
MacDonald
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Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232.
Ong
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D000217:Acyltransferases / Q000378:metabolism*; D000818:Animals; D005033:Ethylmaleimide / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D008862:Microsomes, Liver / Q000201:enzymology*; D010664:Phenylmethylsulfonyl Fluoride / Q000494:pharmacology; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D013045:Species Specificity; D013379:Substrate Specificity
D010743:Phospholipids; D010664:Phenylmethylsulfonyl Fluoride; D000217:Acyltransferases; C056942:lecithin-retinol acyltransferase; D005033:Ethylmaleimide