Studies on cardiolipin III. Structural identity of ox-heart cardiolipin and synthetic diphosphatidyl glycerol

Chemical synthesis of diphosphatidyl glycerol, a long-chain fatty acid ester of diphosphatidyl glycerol, phosphatidyl diglyceride and phosphatidyl glycerophosphate has stimulated a structural comparison with natural cardiolipin. Although in certain properties the various polyglycerol phospholipids are quite similar, the results of enzymic hydrolyses with phospholipase A (EC 3.1.1.4), acylation studies, optical rotation measurements and chromatography of the intact phospholipids and deacylated products indicated that beef-heart cardiolipin has a diphosphatidyl glycerol structure. Conclusive evidence was obtained by means of the breakdown of the phospholipids with phospholipase C (EC 3.1.4.3). The enzyme was found to hydrolyse both natural and synthetic diphosphatidyl glycerol into 1,2-diglyceride and 1,3-glycerol diphosphate, phosphatidyl glycerophosphate being an intermediate hydrolysis product.