Venomic Analysis of the Poorly Studied Desert Coral Snake, Micrurus tschudii tschudii, Supports the 3FTx/PLA₂ Dichotomy across Micrurus Venoms.

Libia Sanz,Davinia Pla,Alicia Pérez,Alfonso Zavaleta,Bruno Lomonte,Maria Salas,Juan Calvete,Yania Rodríguez

doi:10.3390/toxins8060178

Abstract

The venom proteome of the poorly studied desert coral snake Micrurus tschudii tschudii was unveiled using a venomic approach, which identified ≥38 proteins belonging to only four snake venom protein families. The three-finger toxins (3FTxs) constitute, both in number of isoforms (~30) and total abundance (93.6% of the venom proteome), the major protein family of the desert coral snake venom. Phospholipases A2 (PLA2s; seven isoforms, 4.1% of the venom proteome), 1–3 Kunitz-type proteins (1.6%), and 1–2 l-amino acid oxidases (LAO, 0.7%) complete the toxin arsenal of M. t. tschudii. Our results add to the growing evidence that the occurrence of two divergent venom phenotypes, i.e., 3FTx- and PLA2-predominant venom proteomes, may constitute a general trend across the cladogenesis of Micrurus. The occurrence of a similar pattern of venom phenotypic variability among true sea snake (Hydrophiinae) venoms suggests that the 3FTx/PLA2 dichotomy may be widely distributed among Elapidae venoms.

Highlights

New World genus Micrurus (Elapidae) (Wagler, 1824) [1] represents a monophyletic clade of some 80 currently recognized species of venomous coral snakes [2,3,4,5,6,7,8], the topology of the tree is still unresolved
Envenomings by coral snakes are less frequent than those produced by sympatric pitvipers, by far the most dangerous snakes of South America, accounting for less than 3% of the snakebites recorded in the Americas [19,20,21]
S1, resulted in the identification of ě38 proteins belonging to only four snake venom protein families: three-finger toxin (3FTx), phospholipase A2 (PLA2 ), Kunitz-type, and L-amino acid oxidase (LAO)

Summary

Introduction

New World genus Micrurus (Elapidae) (Wagler, 1824) [1] represents a monophyletic clade of some 80 currently recognized species of venomous coral snakes [2,3,4,5,6,7,8], the topology of the tree is still unresolved. Coral snakes are considered by herpetologists to be among the most beautiful snakes of the planet, as they are adorned with unique combinations of red-, black-, and yellow-colored banding. The venoms of only a handful of the vast number (~130) of species and subspecies that constitute the genus Micrurus have been the subject of proteomic studies (consult Table 2 of [18]). To understand this fact it should be taken into consideration that, despite producing among the most potent neurotoxic venoms of any New World snake, bites and fatalities by coral snakes are very rare. Envenomings by coral snakes are less frequent than those produced by sympatric pitvipers, by far the most dangerous snakes of South America, accounting for less than 3% of the snakebites recorded in the Americas [19,20,21]

Methods

Results

Conclusion