Some structural investigations on phospholipids from membranes.

Abstract

AbstractA complete chemical characterization of phophatidyl glycerol from green leaves and algae demonstrated that 1‐linoleneoyl‐trans‐ख3 represented the major molecular species and its occurrence appeared to be related to photosynthesis.Beef‐heart cardiolipin was demonstrated to be identical to synthetic diphosphatidyl glycerol.Chemical structures of synthetic amino acid esters of phosphatidyl glycerol were compared with those of amino acid and glucosamine containing phospholipids from bacterial cell membranes.The molecular species of lecithin from animal tissues were recognized and the influence of dietary fats on their composition was determined.Physical characteristics of natural and synthetic phospholipids indicate that nature is eloquent to preserve the properties offered by particular fatty acid combinations in the phospholipid molecule.Mammalian tissues were found to contain phospholipase A activity which produces two structurally isomeric monoacyl‐phosphoglycerides.Utilizing five isomeric lysolecithins of known structure micro methods involving enzymic hydrolysis were developed to distinguish among these isomers. Lysolecithins from different natural sources were demonstrated to consist of both 1‐acyl‐glycero‐3‐phosphorylcholine and 2‐acyl‐glycero‐3‐phosphorylcholine.In connection with the nonrandom distribution of fatty acids of different apolarity at the two positions of phosphoglycerides, the various metabolic pathways of lysolecithin enantiomers in red cell ghosts, yeast and liver were investigated using different doubly‐labeled substrates.