Partial comparison studies of proteolytic activities of Bothrops diporus venoms from Brazil and Argentina

ACOSTA OFELIA; TORRES-HUACO, FANK; ROMERO-VARGAS FREY; RODRIGUEZ JUAN PABLO; PONCE-SOTO LUIS; GAY CLAUDIA CAROLINA; MARANGONI SERGIO; LEIVA LAURA CRISTINA

Minas Gerais

Congreso; XI Congresso da Sociedade Brasileira de Toxinologia; 2010

Effects showed by bothropic envenomation suffer markedly influence from the environment, diet, sex and age among others factors. Bothorps diporus (formally now as Bothrops neuwidi diporus) was recently elevated to the species level and is distributed in the southeast of Brasil, Paraguay and in central and north regions of Argentina. Samples venom of Bothops diporus, from the state of Sao Paulo (Brazil) and from the province of Corrientes (Argentina), were analyzed in order to compare their proteolytical activities upon casein (caseinolytic activity) and human plasma (pro-coagulant activity). Venoms showed proteolytic activity upon casein with a minimum proteolytic dose (MPD) of 0,0769mg (Argentina, r = 0,99459) and 2,06mg (Brazil, r = 0,99954); these results suggest that the proteolytic activity of Argentine samples are significantly higher than samples from Sao Paulo. The effect of EDTA (5 mM) and PMSF (2mM) was tested pre-incubating two MPD of venoms with inhibitors (1:1 v/v) for 30 min at 37oC prior to standard proteolytic test. Our results showed that the proteolytic activity of venoms is related to metalloproteinases enzymes. Both venoms presented pro-coagulant activities when incubated with human PPP (poor platelet plasma). The minimum coagulant dose (MCD) of samples calculated shows that the venom from Corrientes (MCD = 9,06μg) has a higher pro-coagulant activity than the venom from Sao Paulo (MCD = 28,41μg). Similar inhibition studies were carry out using 2 MCD from both venoms. Results showed that the pro-coagulant activity was inhibited by EDTA (coagulation time > 600 s), in opposition to PMSF or benzamidine (2mM) suggesting that metalloproteinases are also implicated in this activity. Beside of the evolutionary implications that these results suggest, the information presented here should be consider for the development of specific anti-sera or clinical treatment of patients intoxicated with venom of B. diporus.