Mutacytin-1, a New C-Type Lectin-Like Protein from the Venezuelan Cuaima ( Linnaeus, 1766) (Serpentes: Viperidae) Snake Venom Inducing Cardiotoxicity in Developing Zebrafish () Embryos.

Envenomation by the Venezuelan bushmaster snake () (Serpentes: Viperidae) is characterized by local and cardiac alterations. This study investigates the cardiac dysfunction, tissue destruction, and cellular processes triggered by snake crude venom and a C-type lectin (CTL)-like toxin named Mutacytin-1 (MC-1). The 28 kDa MC-1 was obtained by molecular exclusion, ion exchange, and C-18 (checking pureness) reverse-phase chromatographies. N-terminal sequencing of the first eight amino acids (NNCPQ LLM) revealed 100% identity with Mutina (CTL-like) isolated from , which is a Ca-dependent-type galactoside-binding lectin from and CTL BpLec from The cardiotoxicity in zebrafish of MC-1 was evaluated by means of specific phenotypic expressions and larvae behavior at 5, 15, 30, 40 and 60 min post-treatment. The venom and MC-1 also produced heart rate/rhythm alterations, circulation modifications, and the presence of thrombus and apoptotic phenomenon with pericardial damages. Acridine orange (100 μg/mL) was used to visualize apoptosis cellular process in control and treated whole embryos. The cardiotoxic alterations happened in more than 90% of all larvae under the action of venom and MC-1. The findings have demonstrated the potential cardiotoxicity by venom, suggesting the possibility of cardiovascular damages to patients after bushmaster envenoming.