Huwentoxin-XVI is a 39 amino acids peptide that was discovered from the venom of the Chinese tarantula Ornithoctonus huwena. Huwentoxin-XVI was shown to be a potent blocker of HVA N-type calcium channels with an IC₅₀ value of 60 nM in rat DRG. The blocking effect appears to be similar to that of ω-conotoxin-GVIA and ω-conotoxin-MVIIA. Neverthelss, Huwentoxin-XVI differs from GVIA and MVIIA thanks to its greater reversibility and its higher selectivity for N-type over P/Q type than MVIIA.

Description:

Product code: N/A.Category: High voltage-gated Ca2+ channels.Tags: Cav2.2, N-type.

AA sequence:  Cys¹-Ile-Gly-Glu-Gly-Val-Pro-Cys⁸-Asp-Glu-Asn-Asp-Pro-Arg-Cys¹⁵-Cys¹⁶-Ser-Gly-Leu-Val-Cys²¹-Leu-Lys-Pro-Thr-Leu-His-Gly-Ile-Trp-Tyr-Lys-Ser-Tyr-Tyr-Cys³⁶-Tyr-Lys-Lys-OHDisulfide bonds:     Cys¹-Cys¹⁶, Cys⁸-Cys²¹ and Cys¹⁵-Cys³⁶Length (aa): 39Formula:   C₁₉₆H₂₉₂N₅₀O₅₆S₆Appearance: White lyophilized solidMolecular Weight: 4437.2 DaCAS number: Not availableSource: SyntheticPurity rate: > 98%

For research use only

Reference:

Huwentoxin-XVI, an analgesic, highly reversible mammalian N-type calcium channel antagonist from Chinese tarantula Ornithoctonus huwena

N-type calcium channels play important roles in the control of neurotransmission release and transmission of pain signals to the central nervous system. Their selective inhibitors are believed to be potential drugs for treating chronic pain. In this study, a novel neurotoxin named Huwentoxin-XVI (HWTX-XVI) specific for N-type calcium channels was purified and characterized from the venom of Chinese tarantula Ornithoctonus huwena. HWTX-XVI is composed of 39 amino acid residues including six cysteines that constitute three disulfide bridges. HWTX-XVI could almost completely block the twitch response of rat vas deferens to low-frequency electrical stimulation. Electrophysiological assay indicated that HWTX-XVI specifically inhibited N-type calcium channels in rat dorsal root ganglion cells (IC50 ∼60 nM). The inhibitory effect of HWTX-XVI on N-type calcium channel currents was dose-dependent and similar to that of CTx-GVIA and CTx-MVIIA. However, the three peptides exhibited markedly different degrees of reversibility after block. The toxin had no effect on voltage-gated T-type calcium channels, potassium channels or sodium channels. Intraperitoneal injection of the toxin HWTX-XVI to rats elicited significant analgesic responses to formalin-induced inflammation pain. Toxin treatment also changed withdrawal latency in hot plate tests. Intriguingly, we found that intramuscular injection of the toxin reduced mechanical allodynia induced by incisional injury in Von Frey test. Thus, our findings suggest that the analgesic potency of HWTX-XVI and its greater reversibility could contribute to the design of a novel potential analgesic agent with high potency and low side effects

Deng M., et al. (2014) Huwentoxin-XVI, an analgesic, highly reversible mammalian N-type calcium channel antagonist from Chinese tarantula Ornithoctonus huwena. Neuropharmacol.