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κ-Conotoxin RIIIK

Kappa-M-RIIIK, Kappa- Conotoxin RIIIK, Conotoxin R3.1

A Specific Potent Blocker of KV1.2 K+ Channels

Cat #: STC-650
Alternative Name Kappa-M-RIIIK, Kappa- Conotoxin RIIIK, Conotoxin R3.1
Lyophilized Powder yes
  • Bioassay Tested
  • Origin Synthetic peptide
    MW: 2648 Da.
    Purity: >99% (HPLC)
    Form Lyophilized powder.
    Effective concentration 0.5-200 nM.
    Modifications Disulfide bonds between Cys4-Cys17, Cys5-Cys22, Cys12-Cys23. Thr24- C-terminal amidation. X=Hydroxyproline.
    Molecular formula C106H178N34O33S6.
    Activity κ-Conotoxin-RIIIK blocks KV1.2 with high potency.
    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 κ-Conotoxin-RIIIK inhibits KV1.2 channels heterologously expressed in Xenopus oocytes.
      Alomone Labs κ-Conotoxin-RIIIK inhibits KV1.2 channels heterologously expressed in Xenopus oocytes.
      A. Time course of κ-Conotoxin-RIIIK (#STC-650) action on KV1.2 currents. Current amplitudes were plotted as a function of time. Membrane potential was held at -80 mV and oocytes were stimulated by a 100 ms voltage ramp to +20 mV. 200 nM κ-Conotoxin-RIIIK was perfused as indicated by the bar at +10 mV. B. Superimposed examples of KV1.2 channel current in the absence (control) and presence of 200 nM κ-Conotoxin-RIIIK (taken from the experiment in A).
    References - Scientific background
    1. McKinnon, D. (1989) J.Biol. Chem. 264, 8230.
    2. Gutman, G.A. et al. (2005) Pharmacol. Rev57, 473.
    3. Long S.B. et al. (2005) Science 309, 897.
    4. Terlau H. et al. (2004) Physiol. Rev. 84, 41.
    5. Al Sabi, A. et al. (2004) Biochemistry 43, 8625.
    Scientific background

    KV1.2 is a mammalian voltage-dependent K+ channel, homologous to the Drosophila Shaker K+ channel. KV1.2 was first cloned from rat brain1. Eight Shaker related genes exist in mammals constituting the KV1, subfamily of the large KV channel family of genes2.

    The channel is expressed in neurons and cardiac and smooth muscle tissue as well as in retina and pancreas2. The crystal structure of KV1.2 was recently solved shedding light on the structure of a mammalian voltage-dependent channel3. The functional channel is considered low voltage activated and shows very little inactivation. Therefore, this channel activity influences the membrane potential and excitability of neurons and muscle.

    KV1.2 channels are sensitive to high doses of TEA (560 mM) and low doses of 4-AP (0.59 mM), the “classical” non-selective potassium channel blockers.

    Conotoxins, which are peptides consisting of 10 to 30 amino acid residues, typically have one or more disulfide bonds. Conotoxins have a variety of mechanisms of actions, most of which have not been determined. However, it appears that many of these peptides modulate the activity of ion channels4.

    κ-Conotoxin RIIIK is a 24 amino acid peptidyl toxin isolated from the Conus radiatus (Rayed cone) venom. It blocks Shaker and TSha1 K+ channels. Additionally, it was found that κM-conotoxin RIIIK blocks voltage-activated K+ channels with a novel pharmacophore that does not comprise a dyad motif5.

    Target KV1.2 K+ channels
    Net Peptide Content: 100%
    Last update: 02/03/2021

    κ-Conotoxin RIIIK (#STC-650) is a highly pure, synthetic, and biologically active peptide toxin.

    For research purposes only, not for human use
    Shipping and Ordering information