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μ-Theraphotoxin-Hs2a, Huwentoxin IV, Huwentoxin-4, HwTx-IV

A Potent Blocker of Neuronal TTX-Sensitive Voltage-Gated NaChannel

Cat #: STH-100
Alternative Name μ-Theraphotoxin-Hs2a, Huwentoxin IV, Huwentoxin-4, HwTx-IV
Lyophilized Powder yes
  • Bioassay Tested
  • Origin Synthetic peptide
    MW: 4106 Da
    Purity: >99% (HPLC)
    Effective concentration 20-500 nM.
    Modifications Disulfide bonds between Cys2-Cys17, Cys9-Cys24, and Cys16-Cys31. Ile35 - C-terminal amidation.
    Molecular formula C174H278N52O51S6.
    CAS No.: 526224-73-7
    Activity Huwentoxin-IV specifically inhibits the neuronal tetrodotoxin-sensitive (TTX-S) voltage-gated Na+ channel (IC50 = 30 nM) in adult rat dorsal root ganglion neurons, while having no significant effect on the tetrodotoxin-resistant (TTX-R) voltage-gated Na+ channel1-3.
    1. Peng, K. et al. (2002) J. Biol.Chem. 277, 47564.
    2. Xiao, Y. et al. (2008) J. Biol. Chem. 283, 27300.
    3. Xiao, Y. et al. (2010) Mol. Pharmacol. 78, 1124.
    Shipping and storage Shipped at room temperature. Product as supplied can be stored intact at room temperature for several weeks. For longer periods, it should be stored at -20°C.
    Solubility Any aqueous buffer. Centrifuge all product preparations before use (10000 x g 5 min).
    Storage of solutions Up to two weeks at 4°C or three months at -20°C.
    Our bioassay
    • Alomone Labs Huwentoxin-IV inhibits NaV1.7 channels heterologously expressed in Xenopus oocytes.
      Alomone Labs Huwentoxin-IV inhibits NaV1.7 channels heterologously expressed in Xenopus oocytes.
      A. Time course of current inhibition by 500 nM Huwentoxin-IV (#STH-100) (green). Currents were elicited by a voltage ramp between -80 mV to +20 mV (60 ms) every 10 seconds from holding potential of -80 mV. B. Example traces of current response to voltage ramp application before (black) and during (green) 500 nM Huwentoxin-IV application.
    References - Scientific background
    1. Diao, J. et al. (2003) Toxicon 42, 715.
    2. Xiao, Y. et al. (2008) Toxicon 51, 230.
    3. Peng, K. et al. (2002) J. Biol.Chem. 277, 47564.
    4. Xiao, Y. et al. (2008) J. Biol. Chem. 283, 27300.
    Scientific background Huwentoxin-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 > 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.
    Target TTX-sensitive Na+ channels
    Peptide Content: 100%
    Last update: 04/12/2022

    Huwentoxin-IV (#STH-100) is a highly pure, synthetic, and biologically active peptide toxin.

    For research purposes only, not for human use



    Product citations
    1. Dustrude, E.T.  et al. (2013) J. Biol. Chem. 288, 24316.


    Scientific Background

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