Diglyceride acyltransferase

The third acyl residue is transferred onto diglyceride by means of diglyceride acyltransferase... 

This enzyme [EC 2.3.1.20], also known as diglyceride acyltransferase, catalyzes the reaction of an acyl-CoA with 1,2-diacylglycerol to produce coenzyme A and a triacylglycerol. The acyl-CoA derivative can be palmi-toyl-CoA or other long-chain acyl-CoA compounds. 

The pathways diverge at phosphatidate. In the synthesis of triacylglycerols, phosphatidate is hydrolyzed by a specific phosphatase to give a diacylglycerol (DAG). This intermediate is acylated to a triacylglycerol in a reaction that is catalyzed by diglyceride acyltransferase. Both enzymes are associated in a triacylglycerol synthetase complex that is bound to the endoplasmic reticulum membrane. 

Similar enzymes occur in many tissues. D-a,j8-diglyceride so formed may be converted into many of the glycerophosphatides (see below) or, as demonstrated by Weiss, Kennedy and Kiyasu (1960), it may be esterified by a diglyceride acyltransferase (Acyl-CoA 1,2-diglyceride 0-acyltransferase EC 2.3.1.d) to give triglyceride ... 

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