Huwentoxin XVI(HWTX-XVI ) is composed of 39 amino acid residues including six cysteines. HWTX-XVI is a novel neurotoxin from the venom of Chinese tarantula O. huwena. and specificially block N-type calcium channels. [1]
N-type calcium channels are often highly expressed both in dorsal root ganglia cell bodies and in the synaptic terminals projecting to dorsal horn of the spinal cord N-type calcium channels play important roles in the control of neurotransmission release and transmission of pain signals to the central nervous system.[2]
Electrophysiological assay indicated that HWTX-XVI specifically inhibited N-type calcium channels in rat dorsal root ganglion cells. HWTX-XVI specifically inhibits GVIA sensitive, N-type calcium channels in rat DRG cells.[1]
HWTX-XVI could almost completely block the twitch response of rat vas deferens to low-frequency electrical stimulation. HWTX-XVI ‘s analgesic effects, non-toxic and complete reversibility make it an interesting tool for developing novel drugs for the treatment of N-type calcium channel-related diseases.[1,2]
References:
[1] Deng M, Luo X, Xiao Y etal. , Huwentoxin-XVI, an analgesic, highly reversible mammalian N-type calcium channel antagonist from Chinese tarantula Ornithoctonus huwena. Neuropharmacology. 2014 Apr;79:657-67.
[2] Liu Z, Dai J, Dai L etal. , Function and solution structure of Huwentoxin-X, a specific blocker of N-type calcium channels, from the Chinese bird spider Ornithoctonus huwena. J Biol Chem. 2006 Mar 31;281(13):8628-35.