Compositional and functional characterization of the venom of two snake species from Bothrops genus that underwent a diet shift

• Grant number: 19/24527-4
• Support type: Scholarships abroad - Research Internship - Master's degree
• Effective date (Start): May 20, 2020
• Effective date (End): November 19, 2020
• Field of knowledge: Biological Sciences - Physiology - General Physiology
• Principal researcher: Karen de Morais Zani
• Grantee: Nathália da Costa Galizio
• Supervisor abroad: Stephen Patrick Mackessy
• Home Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
• Research place: University of Northern Colorado (UNC), United States
• Associated to the scholarship: 18/14724-4 - Proteomic and functional characterization of the venom of two species of snakes of the genus Bothrops submitted to diet change, BP.MS

Abstract

Snake venoms are complex mixtures of peptides and proteins naturally modified by Natural Selection to act on subduing, killing and, also, digesting the prey. Venom proteins are exposed to accelerated Darwinian evolution and venom variability is commonly reported at different levels including genus, species, subspecies, populations and individuals. Some studies show strong evidences that venom composition may change with geographic location and age, adapting to different prey types. However, few studies demonstrate diet as an important factor related with venom composition and function. In our recent results studying Bothrops moojeni and B. alternatus venoms, submitted to a diet shift from mammals (Mus musculus) to amphibians (Lithobates catesbeianus), we noticed some important changes in composition and function of these venoms. Regarding B. moojeni individual venoms, shotgun proteomic analysis suggested that the diet shift induced a significative change in the relative abundance of toxins belonging to C-type lectins and snake venom metalloproteases families, which play an important role in the coagulotoxicity of snake venoms. Also, diet based on amphibians seems to decrease the lethality of pooled venoms in mice and increase it in amphibians, although the return to diet based on mammals do not restored the initial values for lethality. In addition, SDS-PAGE of B. alternatus individual venoms showed an increase in the intensity of a ~15 kDa protein band after one year on diet with amphibians, a molecular mass usually associated to C-type lectins and phospholipases A2. Considering the importance of identifying the factors involved in snake venom plasticity, here we propose a deep investigation on (i) the role of diet in the composition of snake venoms, including qualitative and quantitative changes, and (ii) the impact of diet shift on venom enzymatic activities. (AU)