title: Characterization of human placental blood vessel phospholipase A2, demonstration of substrate selectivity for arachidonyl-phosphatidylcholine.
abstract: The hydrolysis of acyl esters in phosphatidylcholine by phospholipase A2 (PLA2) for human placental blood vessel was investigated. The enzyme displayed an alkaline pH optimum and an absolute requirement of Ca2+ for activity. In contrast to rat tissues, the human placental blood vessel PLA2 showed a selective preference for arachidonate over linoleate acyl group at the sn-2 position of phosphatidylcholine.
mesh_terms: D001095:Arachidonic Acids / Q000378:metabolism; D001808:Blood Vessels / Q000166:cytology / Q000201:enzymology*; D002118:Calcium / Q000494:pharmacology; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010713:Phosphatidylcholines / Q000378:metabolism; D010740:Phospholipases / Q000302:isolation & purification*; D010741:Phospholipases A / Q000302:isolation & purification*; D054467:Phospholipases A2; D010742:Phospholipid Ethers; D010920:Placenta / Q000098:blood supply*; D011247:Pregnancy; D013379:Substrate Specificity; D013997:Time Factors
chemical_list: D001095:Arachidonic Acids; D010713:Phosphatidylcholines; D010742:Phospholipid Ethers; C043051:1-O-hexadecyl-2-arachidonyl-sn-glycero-3-phosphocholine; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2; D002118:Calcium