Resumen:
Micrurus is a medically relevant genus of venomous snakes composed of 85 species. Bites
caused by coral snakes are rare, but they are usually associated with very severe and life-threatening
clinical manifestations. Ecuador is a highly biodiverse country with a complex natural environment,
which is home to approximately 20% of identified Micrurus species. Additionally, it is on the list
of Latin American countries with the highest number of snakebites. However, there is no local
antivenom available against the Ecuadorian snake venoms, and the biochemistry of these venoms has
been poorly explored. Only a limited number of samples collected in the country from the Viperidae
family were recently characterised. Therefore, this study addressed the compositional patterns
of two coral snake venoms from Ecuador, M. helleri and M. mipartitus, using venomics strategies,
integrating sample fractionation, gel electrophoresis, and mass spectrometry. Chromatographic
and electrophoretic profiles of these snake venoms revealed interspecific variability, which was
ascertained by mass spectrometry. The two venoms followed the recently recognised dichotomic
toxin expression trends displayed by Micrurus species: M. helleri venom contains a high proportion
(72%) of phospholipase A2
, whereas M. mipartitus venom is dominated by three-finger toxins (63%).
A few additional protein families were also detected in these venoms. Overall, these results provide
the first comprehensive views on the composition of two Ecuadorian coral snake venoms and expand
the knowledge of Micrurus venom phenotypes. These findings open novel perspectives to further
research the functional aspects of these biological cocktails of PLA2s and 3FTxs and stress the need
for the preclinical evaluation of the currently used antivenoms for therapeutic purposes in Ecuador.
