Proteinases are present in the venoms of many snakes and are structurally classified into trypsin-like serine proteinases (SVSPs) and metalloproteinases (SVMPs). SVMPs are found mainly in viperid venoms and are important players in the local hemorrhage and pro-inflammatory pathogenesis observed upon envenomation. SVMPs are classified in three main classes depending on the organization of their domains (P-I, P-II and P-III). They are members of the Reprolysin subfamily of metalloproteinases, which also includes two groups of homologous proteins, ADAMs and ADMTs. The P-III class of SVMPs and the ADAMs/ADAMTs share homologous disintegrin-like (D) and cysteine-rich (C) domains. This structural similarity has guided a number of functional assays currently employed in toxinology studies. HF3 is a P-III classSVMP, which is extremely hemorrhagic, and shows a minimum hemorrhagic dose of 240 fmol on the rabbit skin. Although SVMPs are highly active against mammalian tissues, they do not affect the venom components or the venom gland tissue. One of the aims of this project is to evaluate the substrate repertoire (degradome) of HF3 on human plasma in vitro, using proteomics methodologies. Moreover, the peptide bond cleavage specificity of HF3 will be analyzed using a peptide library derived from human blood plasma. Comparatively, the degradomics of HF3 will be also analyzed using Bothrops jararaca plasma. The results of this study will serve as basis to understand the hemorrhagic effects of HF3, as well as the complex physiopathological process generated by SVMPs that involves the cleavage of plasma proteins.
News published in Agência FAPESP Newsletter about the scholarship: