Lysophosphatidylcholine acyltransferase

This enzyme [EC 2.3.1.23], also called lysolecithin acyl-transferase and lysophosphatidylcholine acyltransferase, catalyzes the reaction of an acyl-CoA derivative with 1-acyl-5 n-glycero-3-phosphocholine to yield coenzyme A and l,2-diacyl-5 n-glycero-3-phosphocholine. The enzyme preferentially acts on unsaturated acyl-CoA derivatives, but l-acyl-5 n-glycero-3-phosphoinositol can also act as the acceptor. 

DAG produced via the action of PA phosphatase can also be converted to PC by the catalytic action of choline phosphotransferase (CPT). Production of polyunsaturated FAs via the catalytic action of membrane-bound desaturases occurs while monounsaturated FAs are esterifled to the glycerol backbone of PC. The combined forward and reverse reactions catalyzed by lysophosphatidylcholine acyltransferase (LPCAT) are believed to facilitate acyl exchange at the sn-2 position of PC, with the acyl-CoA pool thereby allowing incorporation of polyunsaturated FA into TAG via the acyl-CoA-dependent acyltransferase reactions in the mainstream of TAG biosynthesis. The reverse reaction of CPT to produce DAG provides a second opportunity to introduce polyunsaturated FA into TAG. In addition, phospholipase A2 may catalyze the release of free FA from PC. The liberated FA could be reesterified as acyl-CoA for use in the mainstream of TAG biosynthesis. 

Demandre, C., Bahl, J., Serghini, H., Alpha, M.J., and Mazliak, P. (1994) Phosphatidylcholine Molecular Species Formed by Lysophosphatidylcholine Acyltransferase from Soya Bean Microsomes, Phytochemistry 35,1171-1175. 

Stymne, S. and Stobart, A.K. 1984a. Evidence for the reversibility of the acyl-CoA Lysophosphatidylcholine acyltransferase in microsomal preparations from developing safflower (Carthamus tinctorius L.) cotyledons and rat liver. Biochem. J. 223 305-314. 

PHOTOAFFINITY LABELING OF LYSOPHOSPHATIDYLCHOLINE ACYLTRANSFERASE FROM DEVELOPING CASTOR BEAN ENDOSPERM... 

Arroyo-Caro, J.M., Chileh, T., Kazachkov, M., Zou, J., Lopez-Alonso, D., Garcia-Maroto, F., 2013b. Molecular characterization of a lysophosphatidylcholine acyltransferase gene belonging to the MBOAT family in Ricinus communis L. Lipids 48, 663-674. 

Lysolecithin (lysophosphatidylcholine) may be formed by an alternative route that involves lecithin cholesterol acyltransferase (LCAT). This enzyme. 

Hg.3. Effect of methanol concentration on acyltransferase activity of lipolytic acyl hydrolase. Amounts of free fatty acids (circles) and fatty acid methyl esters formed (triangles) or lyso-phosphatidylcholine deacylated (squares) in 10-min incubations at 2S°C are given as percentage of substrate (lysophosphatidylcholine) added. (Reproduced from Galliard and Dennis, 1974, by permission.)... 

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