ω-Conotoxin GVIA (trifluoroacetate salt)

ω-Conotoxin GVIA is a peptide originally isolated from the marine mollusk C. geographus that acts as an N-type calcium channel blocker. It binds to human neocortical, rat hippocampal, and chick brain synaptic plasma membranes (IC50s = 4.6, 60, and 150 pM, respectively, in radioligand binding assays). ω-Conotoxin GVIA inhibits norepinephrine and acetylcholine release from human neocortical slices (IC50s = 14 and 3 nM, respectively) and calcium influx into chick synaptosomes by 92% when used at a concentration of 0.1 μM. It blocks electrically-evoked twitch responses of rat vas deferens and guinea pig ileum (IC50s = 9.8 and 55 nM, respectively) but does not affect the postjunctional contractile responses induced by norepinephrine on vas deferens or by carbamoylcholine on ileum. ω-Conotoxin GVIA does not affect potassium-induced contraction of rat aorta at concentrations up to 1 μM.