Venom Proteomic Analysis of Two Medically Important Nigerian Viper (Echis Ocellatus and Bitis Arietans) Snake Species

Snakebite envenoming remains a neglected tropical disease, which poses severe health hazard, especially for the rural inhabitants in Africa. In Nigeria, vipers are the most toxin-producing snakes that cause the highest number of deaths. Hydrophilic interaction liquid chromatography coupled with LC-MS/MS was used to analyze the crude venom extracts of Echis ocellatus (Carpet viper) and Bitis arietans (Puff adder) in order to understand their venom proteomic identities. Results obtained revealed that gel-free proteomic analysis of the crude venom extracts from E. ocellatus and B. arietans yielded the identification of 85 and 79 proteins, respectively. Seventy-nine (79) proteins were common between the two snake species with a 90.8% similarity score. The identified proteins belong to 12 protein families where serine proteases (22.31%) and metalloproteinases (21.06%) were the dominant proteins in the venom of B. arietans . Metalloproteinases (34.84%), phospholipase A 2 s (25.69%) and serine proteases (17.25%) represents the major toxins in the E. ocellatus venom. Other protein families such as three-finger toxins and cysteine-rich venom proteins were also detected, albeit, in low proportions. This study represents the venom proteomic analysis of the two Nigerian viper species, which provides some valuable insights into the toxin families to be neutralized in case of envenomation. Data are available via ProteomeXchange with identifier PXD024638.