Stereospecificity of monoacylglycerol acyltransferase activity from rat intestine and suckling rat liver.
The stereospecificity of monoacylglycerol acyltransferase from rat intestinal mucosa and suckling rat liver microsomes was examined using sn-1,2-diacylglycerol kinase from Escherichia coli. With 2-monooleoyl glycerol and palmitoyl-CoA, 88 and 87.9% of the diacylglycerol synthesized by the intestinal mucosa and suckling liver, respectively, was demonstrated to be the sn-1,2-isomer. Analysis of similar preparations of these diacylglycerol products by gas-liquid chromatography-mass spectrometry indicated that most of the remaining diacylglycerol was the 1,3-isomer that probably arose via acyl-migration. These results indicate that monoacylglycerol acyltransferase is stereospecific. Measurement of acyltransferase activities in microsomes using 1- and 2-monoacyl- and monoalkylglycerols as substrates indicated that the monoacylglycerol acyltransferases from suckling liver and intestinal mucosa have different substrate specificities.
D000217:Acyltransferases / Q000378:metabolism*; D000818:Animals; D000833:Animals, Suckling; D004075:Diglycerides / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D007413:Intestinal Mucosa / Q000201:enzymology*; D007536:Isomerism; D008099:Liver / Q000201:enzymology*; D008862:Microsomes, Liver / Q000201:enzymology; D051381:Rats; D013237:Stereoisomerism
D004075:Diglycerides; D000217:Acyltransferases; C021802:2-acylglycerol O-acyltransferase