{"product_id":"huwentoxin-iv-bhp21300213","title":"Huwentoxin-IV","description":"\u003ch2\u003eOverview\u003c\/h2\u003e \u003cp\u003e\u003cstrong\u003eHuwentoxin-IV\u003c\/strong\u003e is a research-grade protein\/peptide reagent used in research settings. It is commonly applied as a tool reagent related to \u003cstrong\u003eTTX-sensitive Na+ channels\u003c\/strong\u003e biology and\/or assay development. It is supplied in Lyophilized format to support flexible downstream use in RUO workflows. Researchers commonly pair it with applications such as Electrophysiology.\u003c\/p\u003e \u003ch2\u003eKey elements and design rationale\u003c\/h2\u003e \u003cul\u003e \u003cli\u003e\n\u003cstrong\u003eMolecular identity:\u003c\/strong\u003e CAS: 526224-73-7, MW: 4106.8 Da, Formula: C174H278N52O51S6.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSource \/ origin:\u003c\/strong\u003e Cyriopagopus schmidti (Chinese bird spider) (Haplopelma schmidti).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuality attributes:\u003c\/strong\u003e Purity: ≥99% (HPLC); Bioassay tested: Yes; Sterile \/ endotoxin-free: No.\u003c\/li\u003e \u003c\/ul\u003e \u003ch3\u003eModifications\u003c\/h3\u003e \u003cp\u003eDisulfide bonds between Cys2-Cys17, Cys9-Cys24, and Cys16-Cys31 Ile35 - C-terminal amidation\u003c\/p\u003e \u003cp\u003eWhen used as a biochemical or pharmacological tool, results are best interpreted relative to the experimental system (species, expression level, and assay readout) and with appropriate negative and competition-style controls where relevant. This product is intended for research use only.\u003c\/p\u003e \u003ch2\u003eBiological background\u003c\/h2\u003e \u003cp\u003eHuwentoxin-IV is a 35 amino acid peptidyl toxin isolated from the tarantula Haplopelma schmidti venom and its structure represents a typical cystine knot motif1. Huwentoxin-IV acts selectively on tetrodotoxin-sensitive (TTX-S) voltage-gated Na+ channels, with an IC50 of 30 nM in rat DRG neurons. It preferentially inhibits central neuronal voltage-gated Na+ channel subtypes: hNaV1.7 (IC50 of 26 nM), rNaV1.2 (IC50 of 150 nM), and rNaV1.3 (IC50 of 338 nM), compared with muscle subtypes rNaV1.4 and hNaV1.5 (IC50 is \u0026gt; 10 µM)2. Huwentoxin-IV inhibits Na+ channels by trapping the voltage sensor of domain II of the site 4 in the inward, closed configuration3,4.\u003c\/p\u003e \u003ch2\u003eResearch relevance and current trends\u003c\/h2\u003e \u003cul\u003e \u003cli\u003eUsing high-specificity ligands, toxins, and engineered peptides to dissect closely related receptor\/channel subtypes and signaling microdomains.\u003c\/li\u003e\n\u003cli\u003ePairing labeled (e.g., fluorescent) proteins\/peptides with advanced imaging to map surface expression, trafficking, and nanoscale organization.\u003c\/li\u003e\n\u003cli\u003eIncreasing emphasis on reproducibility through standardized characterization (identity, purity, and lot QC) and transparent reporting of reagent attributes.\u003c\/li\u003e \u003c\/ul\u003e \u003ch2\u003eCommon research applications\u003c\/h2\u003e \u003cul\u003e \u003cli\u003eElectrophysiology: commonly used to compare signal, binding, or functional readouts across conditions without implying a specific protocol.\u003c\/li\u003e \u003c\/ul\u003e \u003cp\u003eAcross these use cases, changes in signal or functional readout are generally interpreted as evidence of differences in target abundance, accessibility, or engagement, but alternative explanations (matrix effects, off-target interactions, or assay artifacts) should be considered.\u003c\/p\u003e \u003ch2\u003eNotes for experimental interpretation\u003c\/h2\u003e \u003cul\u003e \u003cli\u003eAssay context matters: binding assays, functional modulation, and detection workflows can yield different readouts even for the same target system.\u003c\/li\u003e\n\u003cli\u003eTarget complexity: closely related family members, splice variants, and post-translational modifications can influence apparent specificity and potency.\u003c\/li\u003e\n\u003cli\u003eMatrix and sample effects: buffer composition, detergents, and biological matrices may alter stability or apparent activity; interpret with appropriate controls.\u003c\/li\u003e\n\u003cli\u003eControl concepts: include negative controls and orthogonal validation (e.g., genetic perturbation or alternative reagents) to support robust interpretation.\u003c\/li\u003e \u003c\/ul\u003e \u003c!-- Sources (internal): - UniProt Knowledgebase (UniProtKB) — UniProt Consortium — https:\/\/www.uniprot.org\/ - NCBI Gene — National Center for Biotechnology Information (NCBI) — https:\/\/www.ncbi.nlm.nih.gov\/gene\/ - NCBI Protein — National Center for Biotechnology Information (NCBI) — https:\/\/www.ncbi.nlm.nih.gov\/protein\/ - PubChem — NIH\/NLM\/NCBI — https:\/\/pubchem.ncbi.nlm.nih.gov\/ - IUPHAR\/BPS Guide to Pharmacology — IUPHAR\/BPS — https:\/\/www.guidetopharmacology.org\/ - RCSB Protein Data Bank (PDB) — RCSB PDB — https:\/\/www.rcsb.org\/ - NCBI Bookshelf — NIH\/NLM — https:\/\/www.ncbi.nlm.nih.gov\/books\/ --\u003e","brand":"Alomone Labs","offers":[{"title":"Default Title","offer_id":53073018519917,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7424\/7277\/files\/STH-100_gr_844.gif?v=1772699892","url":"https:\/\/www.ebiohippo.com\/products\/huwentoxin-iv-bhp21300213","provider":"BioHippo","version":"1.0","type":"link"}