Partial Characterization of three crude venoms different from Crotalus durissus collilineatus snake

¹Torres, F.S.; ¹Oliveira, C.C.; ¹Santos Filho, N.A.; ²Costa J. de O.; ¹Oliveira, F.

1 Instituto de Biomedicina- Universidade Federal de Uberlândia, , Minas Gerais, Brasil, 2 Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, Minas Gerais, Brasil.

In this work, we partially characterized three crude venoms from Crotalusdurissus collilineatus snake which possess different colors: C1-White, C2-clear yellow and C3-dark yellow. All venoms were dissolved in saline (NaCl 0.9%) and quantified by the method of Microbiuret. Defibrinating activity was evaluated after administering i.p. 1-30 mg of each venom in male Swiss mice. After one hour, animals were anesthetized with ether and bled by cardiac puncture. Whole blood was placed in tubes and kept at 25–30°C until clotting occurred. Clotting activity was determined by mixing 50-100mg of each venom with 200 mL of bovine plasma, at 37ºC, and determining the clotting time. The minimum defibrinating and coagulant doses (DMD-DMC) were defined as the lowest amount of venom that inhibited blood coagulation in the mice and clotted plasma within one minute, respectively. Proteolytic activity was tested on azocasein as substrate (1mg /ml 0.2M Tris/HCl, pH 8.8, 0.004M CaCl2). A_{366 nm} is a measure of the degree of proteolytic degradation of azocasein by the sample. The median lethal dose (LD50) was assessed injecting various amounts of the venoms, diluted in 200mL of saline, i.p. in mice. Deaths occurring within 24h were recorded. All crude venom (C1, C2 and C3) caused defibrinogenation when administered i.p. to mice, making the plasma uncoagulable. The fibrinogen levels became very low after 1 hour of the injection of 1.0, 3.0 and 30mg of the each venom, respectively. C1, C2 and C3 acted on azocasein with specific activity of 55.5, 440 and 213.5 units/mg and showed the minimum coagulant concentration of 74, 65 and 80mg, respectively. C1, C2 and C3 presented DL50 of approximately 60, 150 and 110 mg/kg body weight of mice, respectively. Our results showed that the crude venoms different from Crotalusdurissus collilineatus snake present different biochemical properties.

Correspondence to: foliveira@umuarama.ufu.br