Haemorrhagic protein of Russell's viper venom with fibrinolytic and esterolytic activities.

A haemorrhagic toxin specifically active on skin and muscle at the site of introduction in mice has been purified from Vipera russelli russelli (Indian subspecies of Russell's viper) venom by CM-Sephadex C-50 ion exchange chromatography and size exclusion (SE)-HPLC. This toxic protein also has strong fibrinolytic and arginine esterolytic activities. The purified preparation was a single polypeptide chain of molecular weight 73,000, as revealed by SDS-PAGE and SE-HPLC under native and denatured conditions. It has been named as VRR-73. Atomic absorption spectrometry indicated the existence of Mg(2+) in a mol per mol ratio. Antiserum was effective in neutralizing haemorrhage when administered immediately following VRR-73 but was ineffective in inhibiting fibrinolytic and esterolytic activities. On the other hand phenylmethyl sulphonyl fluoride and EDTA inhibited fibrinolysis and esterolysis but did not affect haemorrhage. Thermal denaturation of VRR-73, after exposure at 100 degrees C for 10 min, led to inactivation of all of its activities. Fibrinolytic and esterolytic activities, but not the haemorrhagic activity, were slowly regained after cooling at 25 degrees C. Thus the two pathological activities of VRR-73 appear to be associated with two different regions of the molecule.