Free shipping starts now, no minimum, no coupons required!

OsK-1 Toxin

K+ channel toxin α-KTx 3.7, OsK1

A Potent Blocker of KV1.3 and KCa3.1 K+ Channels

Cat #: STO-150
Alternative Name K+ channel toxin α-KTx 3.7, OsK1
Lyophilized Powder yes
  • Bioassay Tested
  • Origin Synthetic peptide
    MW: 4205 Da
    Purity: >98% (HPLC)
    Form Lyophilized powder.
    Effective concentration 5-100 nM.
    Modifications Disulfide bonds between Cys8-Cys28, Cys14-Cys33 and Cys18-Cys35.
    Molecular formula C177H300N56O46S8.
    Activity OsK-1 inhibits KV1.1, KV1.2, KV1.3 channels potently and KCa3.1 channel moderately1.
    1. Mouhat, S. et al. (2005) Biochem. J. 385, 95.
    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.
    Storage of solutions Up to one week at 4°C or three months at -20°C.
    Our bioassay
    • Alomone Labs OsK-1 Toxin blocks KV1.3 channels expressed in Xenopus oocytes.
      Alomone Labs OsK-1 Toxin blocks KV1.3 channels expressed in Xenopus oocytes.
      A. Representative time course of OsK-1 Toxin (#STO-150) inhibition of normalized KV1.3 current. Membrane potential was held at -100 mV, current was elicited by a 100 ms voltage ramp to +60 mV every 10 sec, and significantly inhibited by 2 nM OsK-1 (green). B. Superimposed traces of KV1.3 current after application of control (black) and of 2 nM OsK-1 Toxin (green), taken from the recording in A.
    References - Scientific background
    1. Grishin, E.V. et al. (1996) Pure Appl. Chem. 68, 2105.
    2. Mouhat, S. et al. (2005) Biochem. J385, 95.
    3. Jaravine, V.A. et al. (1997) Biochemistry 36, 1223.
    Scientific background OsK1 (α-KTx3.7) is a 38-residue toxin cross-linked by three disulphide bridges, originally isolated from the venom of the Asian scorpion Orthochirus scrobiculosus.1 The toxin was found to block a number of K+ channels, both voltage-dependent and Ca2+-activated isoforms. OsK-1 is lethal in mice by intracerebroventricular injection, with a LD50 value of 2 mg/kg. OsK-1 blocks mKV1.1, mKV1.2, mKV1.3 channels potently and hKCa3.1 channel moderately, with IC50 values of 0.6, 5.4, 0.014 and 225 nM, respectively.2 No inhibition effects were observed on KV1.4, KV1.5, KV1.6, KV1.7, KV11, KCa2.1, KCa2.2, KCa2.3 and KCa1.1 channels at µM concentrations.2
    Target KV1.1, KV1.2, KV1.3, and KCa3.1 K+ channels
    Peptide Content: 100%
    Last update: 06/11/2022

    OsK-1 Toxin (#STO-150) is a highly pure, synthetic, and biologically active peptide toxin.

    For research purposes only, not for human use



    1. Human CD4 T-cells (10-100 pM).
      Fung-Leung, W.P. et al. (2017) PLoS ONE 12, e0170102.
    Product citations
    1. Fulton, S. et al. (2011) J. Biol. Chem. 286, 9360.


    Scientific Background

    Shipping and Ordering information