jararaca venom, the serine peptidases and the metallo peptidases. For this, a set of FRETs substrates was tested and two substrates that are mostly hydrolyzed by each one of these classes were found. The metallo peptidases act mainly on Abz-FASSAQ-EDDnp and the serineproteases on Abz-RPPGFSPFRQ-EDDnp. Table 1 shows that Abz-FASSAQ-EDDnp hydrolysis was totally inhibited by both EDTA and 1,10-phenantroline and, thus, it was named

here as Abz-Metal. This was unlike the hydrolysis of Abz-RPPGFSPFRQ-EDDnp peptide, that was strongly inhibited by PMSF (71%), and was thus named as Abz-Serine. It is important to mention that the rate of hydrolysis of Abz-Metal by the BjV is around 18 times lower when compared to that of Abz-Serine ( Table 1). The preference of both protease classes for these substrates was also found in venoms see more from other species of the Bothrops genus that comprise the pool used in the production of the antivenom selleck kinase inhibitor ( Fig. 1), with exception of the Abz-Serine hydrolysis

by the B. neuwiedi venom which was inhibited by PMSF with lower potency. The tests were conducted using the maximum dose of BjV neutralization that was found (10 ìL of antibothropic serum), and incubated at room temperature for 30 min using the Abz-peptides. When the venom from B. jararaca was used, we observed a great neutralization of proteolytic activity of metallo peptidases that act on the substrate Abz-Metal, reaching levels above 90%, and a poor inhibition of serine peptidases that act on Abz-Serine, with levels below 40% ( Table 2). After determining the best condition to neutralize the proteolytic activity of BjV, the same protocol was used to verify the blocking effect of the commercial serum upon the other venoms used to compose the immunization pool: B. alternatus, B. jararacussu, B. moojeni and B. neuwiedi. Fig. 2 shows that the other Bothrops spp

venoms studied here present the same pattern of activities LY294002 that were observed when the B. jararaca venom was used. The hydrolysis of Abz-Serine by the B. neuwiedi venom was not inhibited through the use of the antivenom. The results obtained using B. jararaca and B. moojeni venoms showed inhibition levels of Abz-Serine hydrolysis of around 35%. The hydrolysis of Abz-Metal by the B. alternatus venom was blocked around 70% by the commercial serum. For the other species, the results obtained using the Abz-Metal as substrate always reached levels above 90%. Thus, the use of Abz-Metal and the antivenom reaching nearly 100% of inhibition in return got poor inhibition of serine peptidases that act on Abz-Serine with levels below 50%–0% inhibition ( Fig. 2). One of our goals was to find new peptidic substrates that could be hydrolyzed by bothropic venoms and that could explain in greater depth the Bothrops venoms mechanism.