Proteomic/Glycoproteomic characterization of the venoms of the Bothrops jararaca complex with emphasis on the N-terminome and N-glycome of toxins

Abstract

The comprehensive knowledge of venom proteome complexity of Bothrops species is important because these snakes cause most accidents in Brazil. Besides ecological and taxonomical implications, knowledge of the natural history and toxin composition of venoms is of fundamental importance for the treatment of envenomation and in the selection of specimens for the preparation of venom pools for antivenom production. The Jararaca complex is composed of the nominal species Bothrops jararaca, which has a broad geographical distribution in the Southeastern region of Brazil including some islands, and two insular species (B. insularis and B. alcatraz) as well as the recently described B. otavioi species. Venoms of the Bothrops genus cause a complex pathological envenomation, with local tissue damage and systemic effects on the hemostatic and cardiovascular systems. Variability in the venom proteome/peptidome is a well-documented phenomenon. It occurs at several levels including intergenus, interspecies, and intraspecies variation. Moreover, venom composition may be influenced by the geographical origin and habitat of the snake. Despite the use of various high throughput approaches in toxinology studies, the natural proteome of snake venoms, i.e. the diversity of toxins that is present in the venoms in native form just after synthesis/secretion by the venom gland cells, is poorly known. Likewise, little is known about the post-translational modifications (PTM) present in toxins of Bothrops venoms and how they vary among species. Glycosylation is a frequent protein PTM and considering that a number of toxins in Bothrops venoms are glycosylated it is reasonable to assume that they could display a role in human envenomation cases. The main goal of this study is to use mass spectrometric approaches to analyze the N-terminal sequences of proteins and peptides (natural N-terminome) present in the venoms of B. jararaca and B. alcatraz as well as their glycoproteome and N-glycome, in order to understand the complex evolution process of these species. (AU)