Conotoxins: Modulators of Ion Channel and their Applications
Conotoxin is a group of neurotoxic peptides isolated from the venom of marine snail. It works in a concerted manner to shut down the prey’s nervous system. They are potent neurotoxins that target ion channels & receptors, and inhibit pain pathways by blocking calcium and sodium channels. It is classified into α, δ, γ, δ, κ, ω, ρ, χ, σ, μ, conopressin, conantokin, contulakin. Each conotoxin has its own action for example: sodium channel is inhibited by μ-conotoxin where as activated by δ-conotoxins. They are used as tools for research including determining how specific receptors and channels work. More number of potential pharmaceuticals has been derived from conotoxins. ρ-Conopeptide TIA, isolated from the venom of conus tulipa is the only known conopeptide with activity at adrenergic receptors selectively inhibits human and hamster α1B receptor in an allosteric manner. Ziconotide is a synthetic version of ω – conotoxin MVIIA, found in the venom of fish hunting marine snail, conus magus. Ziconotide is approved by regulatory bodies worldwide as a therapeutic approach for the symptomatic management of severe chronic pain and it is non-addictive and does not appear to induce the devolpment of tolearance. There are an estimated 50,000 to 100,000 conotoxins and approximately 0.1% has been characterized pharmacologically.