Analysis of the function of sialic acid present in the glycan chains of proteinases from Bothrops venoms

• Grant number: 19/24760-0
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: June 01, 2020
• End date: September 30, 2020
• Field of knowledge: Biological Sciences - Biochemistry - Chemistry of Macromolecules
• Principal Investigator: Solange Maria de Toledo Serrano
• Grantee: Carolina Brás Costa
• Supervisor: Oliver Schilling
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
• Institution abroad: University of Freiburg, Germany
• Associated to the scholarship: 17/09929-3 - Bothrops snake venoms: impact of glycosylation on the complexity of proteomes and toxins function, BP.DD

Abstract

Protein glycosylation is one of the major post-translational modifications (PTMs) in viperid snake venoms, and contributes to diversification of proteomes. We have shown that Bothrops venoms are markedly defined by their content of glycoproteins, and that most N-glycan structures present in eight Bothrops venoms contain sialic acid units. To further investigate proteome venom variation and the mechanisms involved in the generation of different venoms by related snakes, in this investigation we are analyzing the subproteomes of glycoproteins selected by lectins with different saccharide specificities and the role of sialic acid in the activity of proteinases present in nine Bothrops venoms. Removal of sialic acid changed the pattern of gelatinolysis of most venoms, and decreased both the proteolytic activity of some venoms on fibrinogen, and the human plasma coagulant activity of all venoms, indicating that sialic acid units may play a role in the activity of venom proteinases. In contrast, the amidolytic profile of venoms did not change after the removal of sialic acid and incubation with Bz-Arg-pNA, indicating that sialic acid is not essential in N-glycans of serine proteinases acting on small substrates. In the context of this project, we intend to extend the characterization of the function of sialic acid present in the glycan chains of proteinases from B. jararaca and B. insularis venoms. To this end we propose to analyze the degradome of both venoms (non-treated and treated with neuraminidase, to remove sialic acid units) in the human plasma, using the TMT-TAILS approach. (AU)