Structures and functions of crotoxin-like heterodimers and acidic phospholipases A2 from Gloydius intermedius venom: Insights into the origin of neurotoxic-type rattlesnakes.

Abstract

For the first time, a heterodimeric neurotoxic PLA2 (designated as Gintexin) has been isolated from the venom of an Asian pitviper, which shows a characteristic venom gland transcriptome similar to those of the neurotoxic type rattlesnakes. The fact that the venom of G. intermedius is less hemorrhagic than those of other Gloydius species, reveals that incompatible neurotoxic- and hemorrhagic-type venoms have evolved in parallel within the genus Gloydius, like the genus Crotalus. Our findings suggest that G. intermedius is the most probable ancestor of some Neotropical rattlesnakes. The results may revolutionize the theory regarding the origin of type-II rattlesnakes and assist with the diagnosis and clinical management of G. intermedius bites. Furthermore, the possibility of using the currently available antivenoms of Neotropical rattlesnakes to treat G. intermedius bites seems feasible.