Acyl Coenzyme A:1-Acylglycerophosphorylglycerol Acyltransferase from Rat Liver

Rat liver microsomes are capable of catalyzing the acylation of 1-palmitoyl- sn -glycero-3-phosphoryl- rac -glycerol for phosphatidylglycerol formation. The requirements for the reaction appear to be the same as the analogous reaction for lecithin synthesis. In contrast, however, to oleoyl-CoA:1-palmitoyl- sn -glycero-3-phosphorylcholine acyltransferase, which has a pH optimum of 7.0, oleoyl-CoA:1-palmitoyl- sn -glycero-3-phosphoryl- rac -glycerol acyltransferase functions optimally at pH 9.0. The latter is also distinguishable by being more stable at the alkaline pH than the former. The data indicate that in addition to positional specificity and acyl group preferability, acyl-CoA:acyl glycerophospholipid acyltransferases also possess phosphorylalcohol group specificity.