title: Phospholipid substrate-specificity of the L-serine base-exchange enzyme in rat liver microsomal fraction.
abstract: The specificity of the L-serine base-exchange enzyme towards the fatty acid composition of the phospholipid substrate was investigated with a rat liver microsomal fraction. The relative rates of L-serine incorporation into saturated-hexaenoic, saturated-pentaenoic, saturated-tetraenoic, saturated-trienoic, dienoic-dienoic, monoenoic-dienoic, saturated-dienoic and saturated-monoenoic + saturated-saturated phosphatidylserine molecular species were 42, 5, 23, 4, 5, 4, 5 and 11% respectively. This is similar to, but not identical with, the relative mass abundance of these molecular species in total liver cell phosphatidylserines. The results indicate that the substrate-specificity of the L-serine base-exchange enzyme can at least in part explain the observed fatty acid composition of rat liver phosphatidylserines.
mesh_terms: D000818:Animals; D005260:Female; D066298:In Vitro Techniques; D008862:Microsomes, Liver / Q000201:enzymology / Q000378:metabolism*; D019884:Nitrogenous Group Transferases; D010718:Phosphatidylserines / Q000096:biosynthesis*; D010743:Phospholipids / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012694:Serine / Q000378:metabolism; D013379:Substrate Specificity; D014166:Transferases / Q000378:metabolism*
chemical_list: D010718:Phosphatidylserines; D010743:Phospholipids; D012694:Serine; D014166:Transferases; D019884:Nitrogenous Group Transferases; C022370:phospholipid serine base exchange enzyme