| Abstract: | The Analysis of Phospholipids from Cardiac Membranes by Phospholipase A2. Phospholipase A2 from snake venom has been employed to analyse the positional distribution of fatty acids in glycerolipids from guinea pig and pig cardiac membranes. It is known that phospholipase A2 hydrolyses the fatty acids in sn-2 position of 1,2 diacylglycerophospholipids. In cardiac membranes phosphatidylcholine and phosphatidylethanolamine contain along with diacyl esters the corresponding alkenylether analogues of phospholipids. In the present experiments the alkenylether moieties were slowly hydrolysed by phospholipase A2 from snake venom. We therefore separated by TLC lysophosphatides from fatty acids and unattacked phospholipids. The latter were the plasmalogens. The separated lipids were characterized by GLC. In some experiments the phospholipids were labelled with 14C-fatty acids before they were hydrolysed by phospholipase A2. The alkenyl ether chain of plasmalogens seems to negativly influence the hydrolysis of fatty acids in sn-2 position of those phospholipids. |
