K+ channel toxin α-KTx 2.1, NTx, Toxin II.11
A Potent Blocker of KV1.2 and KV1.3 Channels
    Cat #: STN-340
  • Lyophilized Powder
  • Bioassay Tested
  • Origin Centruroides noxius (Mexican scorpion).
    Source Synthetic peptide
    MW: 4194 Da.
    Purity: >98% (HPLC)
    Effective concentration 10-200 nM.
    Modifications Disulfide bonds between Cys7-Cys29, Cys13-Cys34, and Cys17-Cys36. Asn39 - C-terminal amidation.
    Molecular formula C174H291N51O55S7.
    CAS No.: 85205-49-8.
    Activity Noxiustoxin inhibits KV1.2 and KV1.3 K+ channels1.
    References - Activity
    1. Grissmer, S. et. al. (1994) Mol. Pharmacol. 45, 1227.

    Storage before reconstitution 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.
    Reconstitution Any aqueous buffer. Centrifuge all product preparations before use (10000 x g 5 min).
    Storage after reconstitution Up to two weeks at 4°C or three months at -20°C.
    Our bioassay
    Alomone Labs Noxiustoxin inhibits KV1.3 channels heterologously expressed in Xenopus oocytes.
    Left: Time course of KV1.3 current amplitude in response to test pulses of 100 ms to 0 mV from a holding potential of -100 mV. 200 nM Noxiustoxin (#STN-340) was perfused at the period marked by the horizontal bar. Right: Traces of KV1.3 currents before (red) and during (black) application of Noxiustoxin.
    References - Scientific Background
    1. Possani, L.D. et. al. (1982) Carlsberg Res. Commun. 47, 285.
    2. Grissmer, S. et. al. (1994) Mol. Pharmacol. 45, 1227.
    3. Mullmann, T.J. et. al. (2001) Biochemistry 40, 10987.
    4. Martinez, F. et. al. (1996) Toxicon 34, 1413.
    5. Stiges, M. et. al. (1986) J. Neurosci. 6, 1570.
    6. Drakopoulou, E. et. al. (1995) Biochem. Biophys. Res. Commun. 213, 901.
    Scientific background Noxiustoxin was originally isolated from the venom of the scorpion Centruroides noxius Hoffmann1 and was shown to interact and inhibit KV1.2 and KV1.3 K+ channels.2 The toxin blocks KV1.3 (recorded using patch clamp in Jurkat cells) with Kd of 6 nM.3 It was shown to bind synaptosomal membranes4 and to increase transmitter release.5 In addition, it was shown to block K+ channels in lymphocytes.6
    Target KV1.2, KV1.3 K+ channels
    Net Peptide Content: 100%
    Last update: 23/12/2018

    Noxiustoxin (#STN-340) is a highly pure, synthetic, and biologically active peptide toxin.

    For research purposes only, not for human use