Positional specificity of saturated and unsaturated fatty acids in phosphatidic acid from rat liver

Abstract

1. 1. The relative incorporation of a number of radioactive fatty acids into the different glycerolipids of rat liver microsomes has been investigated.

2. 2. Studies on the distribution of the radioactivity incorporated into phosphatidylcholine, phosphatidylethanolamine and phosphatidic acid showed that in all three lipids, the majority of the saturated fatty acids were at the 1-position while the polyunsaturated fatty acids were largely confined to the 2-position.

3. 3. The phosphatidic acid fraction of rat liver was isolated in a pure form, and its fatty acid distribution agreed with the results of the incorporation studies.

4. 4. The incorporation of radioactive fatty acids into different molecular species of phosphatidic acid, separated as dimethyl phosphatidates was investigated.