Characterization of the First Conotoxin from Conus ateralbus, a Vermivorous Cone Snail from the Cabo Verde Archipelago.

Jorge L B Neves,Samuel D Robinson,Joanna Gajewiak,Baldomero M Olivera,Samuel Espino,Agostinho Antunes,David Morgenstern,Beatrix Ueberheide,Julita S Imperial,Maren Watkins,Vitor Vasconcelos

doi:10.3390/md17080432

Abstract

Conus ateralbus is a cone snail endemic to the west side of the island of Sal, in the Cabo Verde Archipelago off West Africa. We describe the isolation and characterization of the first bioactive peptide from the venom of this species. This 30AA venom peptide is named conotoxin AtVIA (δ-conotoxin-like). An excitatory activity was manifested by the peptide on a majority of mouse lumbar dorsal root ganglion neurons. An analog of AtVIA with conservative changes on three amino acid residues at the C-terminal region was synthesized and this analog produced an identical effect on the mouse neurons. AtVIA has homology with δ-conotoxins from other worm-hunters, which include conserved sequence elements that are shared with δ-conotoxins from fish-hunting Conus. In contrast, there is no comparable sequence similarity with δ-conotoxins from the venoms of molluscivorous Conus species. A rationale for the potential presence of δ-conotoxins, that are potent in vertebrate systems in two different lineages of worm-hunting cone snails, is discussed.

Highlights

The cone snails are a biodiverse lineage of venomous predators; most species specialize in envenomating a narrow range of prey
We demonstrate that one of the other descendant worm-hunting lineages, which is distant from Tesseliconus, and which is presently restricted to an entirely different biogeographic range, does contain a δ-conotoxin-like that is highly potent on vertebrate targets
Specimens of Conus ateralbus can be reliably collected on the west coast of the Island of Sal from was found consuming a polychaete worm (Figure 3)

Summary

Introduction

The cone snails (genus Conus) are a biodiverse lineage of venomous predators; most species specialize in envenomating a narrow range of prey. On the basis of their primary prey, species in the genus Conus are divided into three broad classes, fish-hunting, snail-hunting and worm-hunting species; the great majority of Conus are vermivorous—worm-hunting. Pioneering studies on cone snail venoms by Endean and coworkers [1] demonstrated that the efficacy of the venom observed on particular animals could be correlated to the prey of that species. Fish-hunting cone snail venoms were highly potent on vertebrates, with worm-hunting Conus venoms much less so. Snail-hunting Conus venoms are extremely potent when tested on gastropods, but much less effective in vertebrate systems. The venom components that are highly expressed are presumably under strong selection for high potency and efficacy on molecular targets in the prey of each Conus species

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Conclusion