CHARACTERIZATION AND AMINO-TERMINAL SEQUENCE OF PHOSPHOLIPASE A(2)-IIFROM THE VENOM OF AGKISTRODON BILINEATUS (COMMON CANTIL)

1. Phospholipase A(2) was isolated from the venom of Agkistrodon bilin eatus by Sephadex G-75 and CM-Cellulose column chromatographies. 2. Th e purified phospholipase A(2) gave a single band on disc polyacrylamid e gel electrophoresis, sodium dodecyl sulfate polyacrylamide gel elect rophoresis and ODS-HPLC. 3. The enzyme preparation had a mel. wt of 14 ,000, isoelectric point of pH 10.12 and possessed 121 amino acid resid ues. 4. The enzyme hydrolyzed the phospholipids phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl inositol and phosphatidyl seri ne. 5. The contraction of mouse diaphragm was inhibited by phospholipa se A(2)-II. 6. Phospholipase A(2) activity of this preparation was inh ibited by ethylenediamine tetraacetic acid, ethlyleneglycol (beta-amin oethyl) N,N,N',N'-tetraacetic acid, p-bromophenacyl bromide or N-bromo succinimide, but not by iodoacetic acid or diisopropyl fluorophosphate . 7. The amino-terminal sequence of the PLA(2)-II was determined.