Anti-metaloproteases: produção e caracterização de anticorpos policlonais IgG anti-metaloproteases purificadas do veneno da serpente Bitis arietans

Abstract

Bitis arietans is a medical importance snake found predominantly in sub-Saharan Africa. The envenomation is characterized by local and systemic reactions, which can lead the victims to death or permanent disabilities. However, the lack of antivenoms makes the treatment worse. Therefore, the present work aimed to identify venom toxins, learn about their properties and develop antitoxins. The F2 fraction obtained from affinity chromatography fractionation of B. arietans venom showed the major proteolytic activity of SVMPs from enzymatic tests. Based on mass spectrometry analysis, 57 different peptides were identified in the F2 fraction. Among the most prevalent peptides are SVMPs. ELISA titration assays performed together with the mouse immunization step (BALB/c) demonstrated the development of anti-F2 fraction antibodies by the animals. The determination of the affinity of antibodies against different Bitis venoms was evaluated, revealing that only the B. arietans venom has peptides recognized by anti-F2 fraction antibodies. In vivo analyzes demonstrated the hemorrhagic capacity of the venom, the effectiveness of the antibodies to inhibit up to 80% of hemorrhage and 0% of the lethality caused by the venom. Taken together, the data indicate: 1) the prevalence of peptides that influence hemostasis and the dissemination of local and systemic effects caused by poisoning; 2) the effectiveness of monospecific antibodies in inhibiting specific activities of the venom; and 3) the isolation of toxins, production and characterization of antibodies is a crucial step in the development of new antivenoms. Therefore, the obtained results help in understanding the mechanism involved in the envenomation and can be useful for the study of new complementary therapies to antivenom in the treatment of accidents by Bitis arietans.