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


Potassium channel toxin α-KTx 2.2, MgTX-theraphotoxin-Hh2a, MgTX

A Blocker KV1.3 and KV1.6 K+ Channels

Cat #: STM-325
Alternative Name Potassium channel toxin α-KTx 2.2, MgTX-theraphotoxin-Hh2a, MgTX
Lyophilized Powder yes
  • Bioassay Tested
  • Origin Synthetic peptide
    MW: 4179 Da
    Purity: >98% (HPLC)
    Effective concentration 50 pM - 50 nM.
    Modifications Disulfide bonds between Cys7-Cys29, Cys13-Cys34, and Cys17-Cys36.
    Molecular formula C178H286N52O50S7.
    CAS No.: 145808-47-5
    Activity Margatoxin is a blocker of KV1.3 and KV1.6 channels.
    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 other 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.
    Our bioassay
    • Alomone Labs Margatoxin inhibits KV1.3 currents expressed in Xenopus oocytes.
      Alomone Labs Margatoxin inhibits KV1.3 currents expressed in Xenopus oocytes.
      A. Time course of Margatoxin (#STM-325) action on Kv1.3 currents. Current amplitudes were plotted as a function of time. Membrane potential was held at –100 mV and oocytes were stimulated by a 100 ms voltage ramp to +60 mV. 0.5 nM Margatoxin were perfused as indicated by the bar (green) at + 55 mV for 180 sec. B. Superimposed examples of KV1.3 channel current in the absence (control) and presence (green) of 0.5 nM Margatoxin (taken from the experiment in A).
    References - Scientific background
    1. Leonard, R.Jet al. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 10094.
    2. Garcia-Calvo, Met al. (1993) J. Biol. Chem268, 18866.
    Scientific background Margatoxin is a peptidyl toxin originally isolated from the scorpion Centruroides margaritatus. It is a specific blocker of KV1.3 channels (IC50~30 pM), but it also blocks KV1.6 and a splice variant of the Drosophila Shaker channels with IC50 of 5 and 150 nM respectively.2 In Xenopus oocytes the toxin is less potent and inhibits expressed KV1.3 channels with an apparent IC50 of ~1 nM.2
    Target KV1.3, KV1.6 K+ channels
    Peptide Content: 100%
    Image & Title Margatoxin
    Alomone Labs Margatoxin blocks KV1.3 channel currents in Jurkat cells and human peripheral blood T cells.Current traces were elicited by 300 ms depolarizing pulses from a holding potential of -80 mV, with 10 mV steps. A. In Jurkat cells. B. In human peripheral blood T cells (PBTC). C. application of 10 nM Margatoxin (#STM-325) nearly completely abolishes currents, confirming that KV1.3 currents are the predominant component of the outward current in Jurkats cells and PTBCs.Adapted from Zhao, N. et al. (2013) PLoS ONE 8, e64629. with permission of PLoS.
    Last update: 06/11/2022

    Margatoxin (#STM-325) 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. Fellerhoff-Losch, B. et al. (2015) J. Neural Transm. 123, 137.
    3. Murray, J.K. et al. (2015) J. Med. Chem. 58, 6784.
    4. Arnoux, I. et al. (2013) Glia 61, 1582.
    5. Hu, L. et al. (2013) PLoS ONE 8, e54267.
    6. Vallejo-Gracia, A. et al. (2013) J. Leukoc. Biol. 94, 779.
    7. Yang, L. et al. (2013) Toxicol. Lett. 223, 16.
    8. Zhao, N. et al. (2013) PLoS ONE 8, e64629.
    9. Guan, Det al. (2011) J. Neurophysiol. 106, 1722.
    10. Martel, Pet al. (2011) PLoS ONE 6, e20402.
    11. Menteyne, Aet al. (2009) PloS ONE 4, e6770.


    Scientific Background

    Shipping and Ordering information