Stichodactyla Toxin-Biotin

Biotinylated ShK Conjugate for Sensitive Detection of KV Channels
  • New
Cat #: STS-400-B
  • Lyophilized Powder
  • Bioassay Tested
  • Origin Stichodactyla helianthus (Caribbean sea anemone).
    Source Synthetic peptide
    MW: 4563 Da.
    Purity: >98% (HPLC)
    Formulation Lyophilized powder.
    Effective concentration 1-100 nM.
    Sequence RSCIDTIPKSRCTAFQCKHSMKYRLSFCRKTCGTC.
    Modifications Disulfide bonds between Cys3-Cys35, Cys12-Cys28, and Cys17-Cys32.
    Label LC-Biotin. The extent of labeling is 1 molecule of biotin per molecule of ShK.
    Structure
    Activity Stichodactyla Toxin blocks KV1.3, KV1.1, KV1.4, and KV1.6 at subnanomolar concentrations and KV3.2 channels at 1000-fold higher concentration than that required to inhibit KV1.3 channels1-3.
    References - Activity
    1. Pennington, M.W. et al. (1995) Int. J. Pept. Protein Res. 46, 354.
    2. Beeton, C. et al. (2003) J. Biol. Chem. 278, 9928.
    3. Middleton, R.E. et al. (2003) Biochemistry 42, 13698.
    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 Stichodactyla Toxin-Biotin blocks KV1.3 channels expressed in Xenopus oocytes.
    A. Representative time course of Stichodactyla Toxin-Biotin (#STS-400-B) inhibition of 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 1 nM Stichodactyla Toxin-Biotin (green). B. Superimposed traces of KV1.3 current following application of control (black) and of 1 nM Stichodactyla Toxin-Biotin (green), taken from the recording in A.
    Alomone Labs Stichodactyla Toxin-Biotin stains rat cerebellum.
    Mildly fixed rat cerebellum sections were incubated with 25 nM Stichodactyla Toxin-Biotin (#STS-400-B) followed by streptavidin-Cy3 (red). Staining of Purkinje cells (vertical arrows) is seen acquired by A. 25x objective B. 40x objective.  Using the 40x objective, grains scattered over the soma of purkinje cells can be seen (horizontal arrows). DAPI (blue) is used as the counterstain.
    References - Scientific Background
    1. Castaneda, O. et al. (1995) Toxicon 33, 603.
    2. Pennington, M.W. et al. (1995) Int. J. Pept. Protein Res. 46, 354.
    3. Beeton, C. et al. (2003) J. Biol. Chem. 278, 9928.
    4. Middleton, R.E. et al. (2003) Biochemistry 42, 13698.
    5. Yan, L. et al. (2005) Mol. Pharmacol. 67, 1513.
    Scientific background

    ShK (Stichodactyla Toxin) is a peptidyl toxin originally isolated from the nematocyst of the sea anemone Stichodactyla helianthus.1

    ShK blocks KV1.3KV1.1KV1.4, and KV1.6 at subnanomolar concentrations and KV3.2 channels at 1000-fold higher concentration than that required to inhibit KV1.3 channels. It has been shown to block KV current in DRG neurons, to displace radioactive Dendrotoxin from brain synaptosomesand inhibit I125-Charybdotoxin binding to Jurkat T lymphocytes with an IC50 of 32 pM.2,4

    Evidence also suggests that native KV currents in the central nervous system, which are predominantly carried by KV1.2 channels, are highly sensitive to this toxin.5

    A fluorescently labeled synthetic ShK is used to recognize and to sort KV1.3 containing lymphocytes.4,6

    Target KV1.1, KV1.3, KV1.4, KV1.6 channels
    Net Peptide Content: 100%

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    Last update: 09/12/2018

    Stichodactyla Toxin-Biotin (#STS-400-B) is a highly pure, synthetic, and biologically active peptide toxin conjugated to biotin.

    Benefits of Stichodactyla Toxin-Biotin:
     Localization and distribution
     Clustering and internalization kinetics
     Live cell imaging
     Single cell detection
     Binding kinetics

    We gladly take on collaboration projects. Please Contact Us.

    For research purposes only, not for human use