Biosynthetic incorporation of cis-parinaric acid into radioactive sn-3-phosphatidic acid.
Isolated guinea pig liver microsomal membranes catalyzed the incorporation of naturally occurring cis-parinaric acid into sn-3-[U-14C]glycerophosphate. This resulted in the formation of sn-3-[14C](parinaroyl)phosphatidic acid, which was isolated by Chelex-100 and DEAE-cellulose column chromatography and further purified by Sephadex-G 25. The sn-3-[14C](parinaroyl)phosphatidic acid thus obtained exhibited absorption and fluorescence spectra substantially different from the cis-parinaric acid. Distribution of the incorporated cis-parinaric acid between the hydroxyl groups of biosynthesized sn-3-[14C]phosphatidic acid was determined by degradation with Crotalus adamanteus venom. This established that the major portion of the incorporated cis-parinaric acid esterified the secondary hydroxyl group in the sn-3-[14C]phosphatidic acid, while the primary hydroxyl group was esterified to a significantly lesser degree. The similarity between the biochemical incorporation of isomeric doxyl stearic acids into lipids of biological membranes and that of cis-parinaric acid into sn-3-phosphatidic acid described in this communication are discussed in relation to the possible use of these probes in studies of intact biological membranes.
D000818:Animals; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D006168:Guinea Pigs; D008862:Microsomes, Liver / Q000378:metabolism*; D010712:Phosphatidic Acids / Q000096:biosynthesis*; D013057:Spectrum Analysis
D005231:Fatty Acids, Unsaturated; D010712:Phosphatidic Acids; C013641:parinaric acid