Purification and properties of phospholipase A2 isozymes from pyloric ceca of the starfish (asterina pectinifera)

Phospholipase A2 isozyme II (PLA2 II) which showed different mobility on native PAGE from that of the PLA2 isozyme I (PLA2 I) isolated previously was purified from pyloric ceca of the starfish (Asterina pectinifera). The PLA2 II was mainly released oleic acid from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine. N-terminal amino acid sequence of the PLA2 II was SVYQF. Temperature and pH optimums of the PLA2 II were at around 50C and pH 9.0, respectively, and the enzyme activity was enhanced by sodium deoxycholate and 1 mM or higher concentration of Ca2+. The PLA2 II did not show the fatty acid specificity for hydrolysis of phosphatidylcholine (PC). Specific activity of the PLA2 II was about 10 times higher than that of commercially available porcine pancreatic PLA2. The PLA2 II hydrolyzed PC more effectively than phosphatidylethanolamine. These characteristics of the PLA2 II were the same as those of the PLA2 I.The definitive version is available at www.blackwell-synergy.co