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Potassium channel toxin alpha-KTX 12 Sp2

Potent Blocker of KV1.and a weaker blocker of KV1.1 and KV1.2 

Cat #: STK-050
Alternative Name Potassium channel toxin alpha-KTX 12 Sp2
Lyophilized Powder yes
  • Bioassay Tested
  • Origin Scorpiops pococki (Scorpion)
    Source Synthetic
    MW: 3928.4 Da
    Purity: >98%
    Form Lyophilized Powder
    Effective concentration 15 - 100 nM
    Modifications Cys8-Cys28, Cys14-Cys33 and Cys18-Cys35
    Molecular formula C155H244N58O49S7
    Activity KTX-Sp2 is a potent blocker of Kv1.3 voltage-gated K+ channels and a weaker inhibitor of Kv1.1 and Kv1.2 channel1.
    1. Zhang, Y. and Zhang, F. et al. (2019) Cell Biosci., 9, 99.
    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. Protect from light and moisture.
    Solubility Soluble in DDW.
    Centrifuge all products before use (10000 x, g 5 min). Avoid multiple freezing and thawing.
    Storage of solutions Store up to one week at 4°C or up to 6 months at -20°C.
    It is recommended to prepare fresh solutions in working buffers before use, or aliquot stock solutions reconstituted in distilled water and keep at -20°C. Upon use, dilute the stock solution in the desired working buffer. Prevent repeated thawing and freezing cycles. 
    Our bioassay
    • Alomone Labs KTX-Sp2 blocks KV1.3 channels expressed in Xenopus oocytes.
      Alomone Labs KTX-Sp2 blocks KV1.3 channels expressed in Xenopus oocytes.
      A. Representative time course of KTX-Sp2 (#STK-050) 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 (green) and 20 nM (magenta) KTX-Sp2.
      B. Superimposed traces of KV1.3 channel currents in the absence (control) and presence of 2 nM (green) and 20 nM (magenta) KTX-Sp2 (taken from the recording in A).
    References - Scientific background
    1. Zhang, Y. and Zhang, F. et al. (2019) Cell Biosci., 9, 99.
    2. Tajti, G. and Wai, D.C.C. et al. (2020) Biochem. Pharmac., 181, 114146.
    3. Norton, R.S.  (2017) Neuropharmac., 127, 124.
    4. Gubič, S. et al. (2021) Med. Res. Rev., 1.
    5. Chandy, K.G. et al. (2017) Curr. Opin. Chem. Biol., 38, 97.
    Scientific background

    a-KTX 12 Sp2 (KTX-Sp2) is a 37 amino acid peptidyl toxin, which was originally screened and genetically engineered from the venom gland transcriptome database from the scorpion, Scorpiops Pocoki1. KTX-Sp2 effectively blocks the voltage-gated potassium (Kv) channel Kv1.3, and also weakly inhibits the Kv1.1 and Kv1.2 channels1. In a Jurkat T cell model system, KTX-Sp2 significantly reduced the levels of intracellular free calcium, inhibited cellular activation, and suppressed the release of the inflammatory cytokine interleukin (IL)-2, which exhibited a robust immunosuppressant effect1.

    Kv channels play key roles in human physiology and pathology. The therapeutic targeting of KV1.3 with specific peptides and small molecule inhibitors shows great promise for treating various cancers and autoimmune diseases, such as multiple sclerosis, type I diabetes mellitus, psoriasis, contact dermatitis, rheumatoid arthritis, and myasthenia gravis2,3,4. In addition, the Kv1.3 channel in T lymphocytes is a validated therapeutic target for diverse autoimmune diseases5 and Ktx-Sp2 robustly inhibits the autoimmune response1.

    Target Kv1.3, Kv1.2, Kv1.1
    Peptide Content: 100%
    Last update: 16/05/2021

    Ktx-Sp2 (#STK-050) is a highly pure, synthetic, and biologically active peptide toxin.

    For research purposes only, not for human use



    Scientific Background


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