Characterization and amino-terminal sequence of phospholipase A 2-II from the venom of Agkistrodon bilineatus (common cantil)

Abstract

1. 1. Phospholipase A 2 was isolated from the venom of Agkistrodon bilineatus by Sephadex G-75 and CM-Cellulose column chromatographies. 2. 2. The purified phospholipase A 2 gave a single band on disc polyacrylamide gel electrophoresis, sodium dodecyl sulfate polyacrylamide gel electrophoresis and ODS-HPLC. 3. 3. The enzyme preparation had a mol. wt of 14,000, isoelectric point of pH 10.12 and possessed 121 amino acid residues. 4. 4. The enzyme hydrolyzed the phospholipids phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl inositol and phosphatidyl serine. 5. 5. The contraction of mouse diaphragm was inhibited by phospholipase A 2-II. 6. 6. Phospholipase A 2 activity of this preparation was inhibited by ethylenediamine tetraacetic acid, ethyleneglycol (β-aminoethyl) N, N, N′, N′-tetraacetic acid, p-bromophenacyl bromide or N-bromosuccinimide, but not by iodoacetic acid or diisopropyl fluorophosphate. 7. 7. The amino-terminal sequence of the PLA 2-II was determined.