PURIFICATION, N-TERMINAL SEQUENCE AND STRUCTURAL CHARACTERIZATION OF A TOXIC PROTEIN FROM THE INDIAN SCORPION-VENOM BUTHUS-TAMULUS

A toxic protein component (Bt-II) was isolated from the venom of the I ndian scorpion, Buthus tamulus, by ion-exchange chromatography on Bior ex-70 and reverse phase high pressure liquid chromatography (RP-HPLC). This 7800 mol. wt protein was found to have an LD50 value of 2.25 mg/ kg body weight in mice by subcutaneous injection. Amino acid compositi on of the protein revealed the presence of aromatic and basic amino ac ids; the N-terminal amino acid sequence was also determined. Structura l characterization of Bt-II, based on circular dichroic and fluorescen t quenching studies, has also been reported.