Exploring venom diversity in Mixcoatlus browni and Mixcoatlus barbouri: A comparative analysis of two rare Mexican snake species with crotoxin-like presence.

The genus Mixcoatlus is composed of three species: Mixcoatlus barbouri, M. browni, and M. melanurus, of which the venom composition of M. melanurus, the most common species of the three, has only recently been described. However, very little is known about the natural history of M. barbouri and M. browni, and the venom composition of these two species has remained thus far unexplored. In this study we characterize the proteomic profiles and the main biochemical and toxic activities of these two venoms. Proteomic data obtained by shotgun analysis of whole venom identified 12 protein families for M. barbouri, and 13 for M. browni. The latter venom was further characterized by using a quantitative 'venomics' protocol, which revealed that it is mainly composed of 51.1 % phospholipases A2 (PLA2), 25.5 % snake venom serine proteases (SVSP), 4.6 % l-amino oxidases (LAO), and 3.6 % snake venom metalloproteases (SVMP), with lower percentages other six protein families. Both venoms contained homologs of the basic and acidic subunits of crotoxin. However, due to limitations in M. barbouri venom availability, we could only characterize the crotoxin-like protein of M. browni venom, which we have named Mixcoatlutoxin. It exhibited a lethal potency in mice like that described for classical rattlesnake crotoxins. These findings expand knowledge on the distribution of crotoxin-like heterodimeric proteins in viper snake species. Further investigation of the bioactivities of the venom of M. barbouri, on the other hand, remains necessary.

Quantifying venom production: A study on Micrurus snakes in Mexico.

Our study quantifies venom production in nine Mexican coral snake species (Micrurus), encompassing 76 specimens and 253 extractions. Noteworthy variations were observed, with M. diastema and M. laticollaris displaying diverse yields, ranging from 0.3 mg to 59 mg. For animals for which we have length data, there is a relationship between size and venom quantity. Twenty-eight percent of the observed variability in venom production can be explained by snake size, suggesting that other factors influence the amount of obtained venom. These findings are pivotal for predicting venom effects and guiding antivenom interventions. Our data offer insights into Micrurus venom yields, laying the groundwork for future research and aiding in medical response strategies. This study advances understanding coral snake venom production, facilitating informed medical responses to coral snake bites.