STUDIES ON BUNGARUS FASCIATUS VENOM

The crude venom of Bungarus fasciatus was separated into thirteen fractions in a CM-cellulose column with ammonium acetate buffer by two-stage gradient elution at 5°C. The pharmacological activities and various enzymic activities of these fractions were investigated. Two fractions (Fractions V and VI) showed cardiotoxic activity and one fraction (Fraction VIII) exhibited neurotoxic action. Three cardiotoxic principles were isolated in pure forms and their pharmacological activities were different from cobra cardiotoxin. The amino acid composition of the three cardiotoxic principles were very similar and molecular weights were about 10,500. The isoelectric points determined by electrofocusing were 9.16, 9-32 and 9.70, respectively. The CD spectra of the three cardiotoxin-like components were almost equivalent and were entirely different from that of cobra cardiotoxin. The cardiotoxin-like components showed no cross reaction to purified antibody of cobra cardiotoxin. The sequence of N-terminal nine amino acid residues are exactly the same as that of cobra phospholipase A2 but shows no phospholipase A activity.