Stereospecificity of monoacylglycerol acyltransferase activity from rat intestine and suckling rat liver.

• Main Authors: R A Coleman, J P Walsh, D S Millington, D A Maltby
• Format: Article
• Language: English
• Published: Elsevier 1986-12-01
• Series: Journal of Lipid Research
• Online Access: http://www.sciencedirect.com/science/article/pii/S0022227520388465

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.