Isolamento e avaliação das atividades biológicas de uma nova metaloproteinase (SVMP) de classe PIII da peçonha de Bothrops atrox

Abstract

The Bothrops atrox, is the main cause of snakebites in the Brazilian Amazon. The venom’s composition of this species suffer variations due to growth and geographic location, but the snake venom metalloproteinases (SVMPs) are the most abundant components of this venom. The SVMPs are responsible for hemorrhage, the most characteristic symptom of Bothrops poisoning. In this study, two pools of full venom of B. atrox were evaluated, from the natural environment (Floresta Nacional do Tapajós, PA, Brazil) and captive (serpentarium of Instituto Butantan, SP, Brazil). The differences in the composition of the two pools of venom were evaluated by reverse phase chromatography. In addition, two SVMPs isoforms from PIII class were isolated by hydrophobic interaction chromatography and anion exchange of the pools evalueted. The pools of venoms showed similar chromatographic profiles, but with quantitative differences in expression of phospholipase A2, SVMPs PI class and serino proteinases, which predominated in the venom of forest area. In both cases, the majority were SVMPs toxins in snake venoms of the two environments. The SVMPs-PIII isolated exhibited hemorrhagic activity and high ability to degrade fibrin in a dose-dependent way. However, only the isoform present in the venom of deriving captive specimens exhibited procoagulant activity in the presence of calcium. After isolation of SVMPs P- III class and sequencing of more than 50 % coverage, we could not detect structural differences between them or with jararhagin (SVMPs-PIII Bothrops jararaca). Though only the jararhagin was able to inhibit platelet aggregation induced by collagen, suggesting the presence of differences between the molecules, or in regions that have not been sequenced or glycosylation. So was isolated a new class of SVMP- PIII venom of B. atrox very similar in structure with jararhagin, but without inhibiting platelet aggregation activity.