Chlorotoxin

CTX, Cltx
An Inhibitor of Chloride Channels
    Cat #: RTC-450
    Alternative Name CTX, Cltx
  • Lyophilized Powder
  • Bioassay Tested
  • Origin Recombinant, E. coli
    MW: 3996 Da.
    Purity: >98% (HPLC)
    Effective concentration 50-600 nM.
    Sequence MCMPCFTTDHQMARKCDDCCGGKGRGKCYGPQCLCR.
    Modifications Disulfide bonds between Cys2-Cys19, Cys5-Cys28, Cys16- Cys33 and Cys20-Cys35.
      • Chlorotoxin
    Molecular formula C158H248N52O48S11.
    CAS No.: 163515-35-3.
    Activity Chlorotoxin blocks small conductance Clchannels of epithelial cells and also blocks Cl- channels expressed in gliomas1,2.
    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 (10000 x g 5 min).
    Storage of solutions Up to four weeks at 4°C or three months at -20°C.
      • Chlorotoxin
        Alomone Labs Chlorotoxin inhibits Ca2+-activated Cl- currents.
        Inhibition of Ca2+-activated Clcurrents by Chlorotoxin (#RTC-450) in human R2 astrocyte cell line. The data are taken from three experiments and the calculated IC50 was 68 nM.
    References - Scientific background
      • Native chlorotoxin (CTX) is a 36-amino acid peptide, originally isolated from the venom of the giant yellow Israeli scorpion Leiurus quinquestriatus hebraeus. Its primary amino acid sequence shows considerable homology to a class of short insectotoxins.1

        Initially, CTX was demonstrated as an irreversible inhibitor of small conductance Cl- channels in colonic epithelial cells and Cl- fluxes across glioma cell membranes.2,3 Inhibition of Cl- channels with CTX prevents cell volume changes, and in turn, inhibits tumor cell invasion and migration.4-6

        Immunohistochemical studies show that CTX specifically and selectively binds to glioma cell lines and to tissue biopsies from patients with various malignant gliomas and other embryonic related tumors of neuroectodermal origin but not to normal brain tissue.

        These findings have lead to clinical evaluation for the therapeutic and diagnostic use of CTX, a synthetic derivate, in patients with malignant glioma. This derivative of CTX has been shown to selectively label human gliomas in vivo and in vitro and demonstrated all of the known physical and biological activities of the naturally occurring CTX.7,8

        Further studies on the interaction of CTX with Cl- channels suggest that these effects are indirect; affinity purification with a recombinant CTX identified the matrix metalloproteinase-2 (MMP2) as a CTX binder in glioma cells. The actual receptor for CTX appears to be a protein complex that contains MMP2 and Cl- channel 3 (ClC-3). Binding of CTX induces endocytosis of this complex and hence the ClC-3 channels. This finding might explain the irreversible action of CTX and its relatively slow time course of Cl- channel blockage.9,10

    Target Chloride channels
    Net Peptide Content: 100%
    Last update: 13/11/2019

    Chlorotoxin (#RTC-450) is a highly pure, recombinant, and biologically active peptide toxin.

    For research purposes only, not for human use