Phospholipase A-.., hydrolysis

An alternative fatty acid was introduced into position 2 following phospholipase A hydrolysis, and final conversion to phosphatidylcholine or phosphatldylethanolamine was accomplished by direct amination. Cytidine diphosphate diacylglycerols are essential Intermediates in the biosynthesis of several... 

Early experiments on phospholipase A used an enzyme from snake venom which released one mole of fatty acid from a diacyl phospholipid. The original studies showed quite clearly that unsaturated fatty acids were released from egg or liver phosphatidylcholines and so it was quite natural to assume that the enzyme was specific for unsaturated acids. When fully saturated or fully unsaturated lipids were the substrates, however, one mole of fatty acid was still released from one mole of phospholipid and it was realized that the enzyme must be specific for one or other of the two positions. Early chemical analyses of the products of phospholipase A hydrolysis seemed to indicate that the enzyme released the fatty acid from the 1-position. When it was discovered that the enzyme also liberates fatty acid from plasmalogen (where it is known quite definitely to be located at the 2-position) the problem was reinvestigated more rigorously. 

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