A protein homology detection between rattlesnakes (Viperidae: Crotalinae) from South and North America deduced from antigenically related metalloproteases

Abstract

Abstract Despite the fact that the analysis of two venom proteins is a limited investigation, the occurrence of proteins antigenically related between two Crotalus species from very distant geographic locations may be of importance to a further understanding of venom immunology. In this study, shared venom antigens of crotaline snakes are determined by immunoprecipitin analysis using rocket line immunoelectrophoresis (RLIE). Metalloprotease components were detected in the venom of Uracoan Rattlesnake (Crotalus vegrandis) from Venezuela, and in the venom of the Western Diamondback Rattlesnake (Crotalus atrox) from Texas, USA. Cross-reactive components detected in both species were identified using rocket line immunoelectrophoresis (RLIE). The present study was focused on a comparison of Crotalus antigens by anode deflection. There was cross-reactivity between Uracoina-1 from C. vegrandis and C. atrox venom tested with polyvalent Bothrops/Crotalus antivenom. Moreover, a common sequence of amino acids has been found between Uracoina-1 (C. vegrandis) and a catrocollastatin precursor from C. atrox. These results confirm the existence of cross-reacting components between antigenic extracts of both snake venoms. Rattlesnakes originally spread from North to South America, and both studied species, which share a similar protein, have probably been separated since the Cretaceous, for more than 80 million years.