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κ-theraphotoxin-Ps1b, κ-TRTX-Ps1b, PaTX2, Kappa-theraphotoxin-Ps1b

A Potent Blocker of KV4 Channels

Cat #: STP-710
Alternative Name κ-theraphotoxin-Ps1b, κ-TRTX-Ps1b, PaTX2, Kappa-theraphotoxin-Ps1b
Lyophilized Powder yes
  • Bioassay Tested
  • Origin Synthetic peptide
    MW: 3922 Da
    Purity: >99% (HPLC)
    Effective concentration 100-500 nM
    Modifications Disulfide bonds between Cys2-Cys16, Cys9-Cys21, and Cys15-Cys25
    Met31 - C-terminal methionine amide
    Molecular formula C169H259N49O43S8
    CAS No.: 221889-63-0
    Activity Phrixotoxin-2 specifically and reversibly blocks KV4.21.
    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 (10,000 x g 5 min).
    Storage of solutions Up to two weeks at 4°C or three months at -20°C.
    Our bioassay
    • Alomone Labs Phrixotoxin-2 inhibits KV4.2 channel expressed in Xenopus oocytes.
      Alomone Labs Phrixotoxin-2 inhibits KV4.2 channel expressed in Xenopus oocytes.
      A. Time course of Phrixotoxin-2 (#STP-710) action on KV4.2 peak current amplitude. Peak current amplitudes were plotted as a function of time. Membrane potential was held at -90 mV and oocytes were stimulated by a 100 ms voltage step to 0 mV. 200 nM Phrixotoxin-2 was perfused as indicated by the bar (green) for 160 sec. B. Superimposed examples of KV4.2 channel maximum peak current in the absence (control) and presence (green) of 200 nM Phrixotoxin-2 (taken from the experiment in A).
    References - Scientific background
    1. Diochot, S. et al. (1999) Br. J. Pharmacol. 126, 251.
    Scientific background Phrixotoxin-2 is a natural peptide isolated from the Phrixotrichus auratus Tarantula venom. It blocks specifically and reversibly KV4.2 and KV4.3 channels.1 These channels are probably the molecular counterparts of the A-type current (Ito1) in the heart. Cloned KV4.2 and KV4.3 channels heterologously expressed in COS cell were blocked with IC50 of 34 and 71 nM of Phrixotoxin-2 respectively1.
    Target KV4 channels
    Peptide Content: 100%
    Last update: 08/11/2022

    Phrixotoxin-2 (#STP-710) is a highly pure, synthetic, and biologically active peptide toxin.

    For research purposes only, not for human use



    Product citations
    1. Meneses, D. et al. (2016) Neural Plast. 2016, 8782518.
    2. Subramaniam, M. et al. (2014) J. Neurosci. 34, 13586.


    Scientific Background

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