ω-Agatoxin TK

ω-Agatoxin TK, a peptidyl toxin of the venom of Agelenopsis aperta, is a potent and selective P/Q type Ca2+ channel blocker. ω-Agatoxin TK inhibits the high K+ depolarisation-induced rise in internal Ca2+ in cerebral isolated nerve endings with an IC50 of of 60 nM. ω-Agatoxin TK has no effect on L-type, N-type, or T-type calcium channels[1][2][3].

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[1]María Sitges, et al. Omega-agatoxin-TK is a useful tool to study P-type Ca2+ channel-mediated changes in internal Ca2+ and glutamate release in depolarised brain nerve terminals. Neurochem Int. 2005 Jan;46(1):53-60.|[2]M Kimura, et al. Involvement of P-type calcium channels in high potassium-elicited release of neurotransmitters from rat brain slices. Neuroscience. 1995 Jun;66(3):609-15.|[3]M Kuwada, et al. Omega-agatoxin-TK containing D-serine at position 46, but not synthetic omega-[L-Ser46]agatoxin-TK, exerts blockade of P-type calcium channels in cerebellar Purkinje neurons. Mol Pharmacol. 1994 Oct;46(4):587-93.