Isolation and characterization of two toxins from the venom of the Malayan cobra (Naja naja sputatrix).

Two principal toxins of the Malayan cobra (Naja naja sputatrix) venom have been purified to electrophoretic homogeneity by successive SP-Sephadex C-25 ion exchange chromatography and Sephadex G-50 gel filtration chromatography. They are designated as sputa-neurotoxin 1 (SN1) and sputa-neurotoxin 2 (SN2), respectively. both toxins belong to the group of short neurotoxins which are composed of approximately 60 amino acid residues. The LD50 values following i.p. injection of the purified toxins are 91 (SN1) and 71 (SN2) micrograms/kg mouse. Amino acid compositions of the two toxins show close similarities to other postsynaptically acting curaremimetic cobra neurotoxins.