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A family of disulfide-knotted spider peptides, several of which block the pain channel Nav1.7.
Also known as: HWTX · HwTx-IV · mu-theraphotoxin-Hs2a
Part of the Foundational & therapeutic peptides cluster
Overview
Huwentoxins are a family of neurotoxic peptides from the venom of the Chinese bird spider, most sharing the highly stable inhibitor cystine-knot (ICK) fold. Different members target voltage-gated calcium or sodium channels; huwentoxin-IV, for example, selectively blocks tetrodotoxin-sensitive sodium channels including Nav1.7. This makes them valuable research tools for studying pain signaling. This page is educational and not medical advice.
Source & context
Biological / chemical source: Venom of the Chinese bird spider (Cyriopagopus schmidti / Haplopelma schmidti)
Primary research or clinical context: Research tools for ion-channel and pain studies
Cystine-knot scaffold
Most huwentoxins fold into an inhibitor cystine knot, in which three disulfide bonds form a ring threaded by a third bridge. This gives exceptional stability across pH and temperature, a property that makes ICK peptides attractive templates for engineering selective, protease-resistant channel modulators.
Channel targets and pain research
Individual huwentoxins act on N-type calcium channels or on voltage-gated sodium channels. Huwentoxin-IV inhibits Nav1.7, a channel central to pain sensation, so it is studied as a probe and lead for non-opioid analgesic research. These remain investigational tools rather than approved medicines.
Structure & chemistry
Molecular identity & reference confidence
Reference mass unavailable
Reference values are taken from the cited molecular record or curated profile. A database match is not independent laboratory verification; modifications, counter-ions, and formulations can change the measured mass.
- Molecular form
- Huwentoxin (source record; form not independently established)
- Species
- Not established by this molecular identity audit
- Termini (N / C)
- Not specified / Not specified
Average reference mass
Reference policy updated: 2026-10-05
- IUPHAR/BPS source snapshot · 2026-09-06
- IUPHAR ligand: 7570
Chemistry values: IUPHAR/BPS Guide to Pharmacology · fetched 2026-09-06.
FAQ about Huwentoxin
What is Huwentoxin?+
Huwentoxins are a family of neurotoxic peptides from the venom of the Chinese bird spider, most sharing the highly stable inhibitor cystine-knot (ICK) fold. Different members target voltage-gated calcium or sodium channels; huwentoxin-IV, for example, selectively blocks tetrodotoxin-sensitive sodium channels including Nav1.7. This makes them valuable research tools for studying pain signaling. This page is educational and not medical advice.
What Canadian product status is recorded for Huwentoxin?+
Canadian product status for Huwentoxin has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.
What is the typical length of Huwentoxin?+
Huwentoxin is not a classic amino-acid chain peptide in the same sense; see the profile for classification details.