μ-Theraphotoxin-Hh2a, Huwentoxin IV
A Potent Blocker of Neuronal TTX-Sensitive Voltage-Gated NaChannel
    Cat #: STH-100
    Alternative Name μ-Theraphotoxin-Hh2a, Huwentoxin IV
  • Lyophilized Powder
  • 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.
      • Huwentoxin-IV
    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.
      • Peng, K. et al. (2002) J. Biol.Chem. 277, 47564.
      • Xiao, Y. et al. (2008) J. Biol. Chem. 283, 27300.
      • 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.
      • Huwentoxin-IV
        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.
      • 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
    Net Peptide Content: 100%
    Last update: 24/01/2020

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

    For research purposes only, not for human use