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A Blocker of Kir1.1, Kir3.1 and Kir3.4 K+ Channels

Cat #: STT-180
Alternative Name TPN-RQ
Lyophilized Powder yes
  • Bioassay Tested
  • Origin Apis mellifera (Honeybee)
    Source Synthetic peptide
    MW: 2496 Da
    Purity: >98%
    Form Lyophilized Powder
    Effective concentration 200 nM
    Modifications Disulfide bonds between Cys3-Cys14 and Cys5-Cys18
    Molecular formula C106H175N37O25S4
    Activity Tertiapin-RQ blocks a range of inward rectifier K+ channels (Kir), in particular ROMK1 and GIRK, with no significant effect on Kir2 family. Additionally, TPN-RQ was shown to have an antidepressive and anxiogenic effect in animal model1.
    1. Okada, M. et al. (2020) PLoS ONE 15, e0233815.
    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 water.
    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. Centrifuge all product preparations before use (10,000 g for 1 min).
    Storage of solutions Store up to one week at 4°C or up to 6 months at -20°C.
    Our bioassay
    • Alomone Labs Tertiapin-RQ blocks Kir1.1 channels expressed in Xenopus oocytes.
      Alomone Labs Tertiapin-RQ blocks Kir1.1 channels expressed in Xenopus oocytes.
      Representative time course of Kir1.1 current, stimulated by a continuous application (top dotted line) of high K+ concentration, and reversible inhibition by 200 nM (green) and 1 µM (magenta) Tertiapin-RQ (#STT-180), at a holding potential of -80 mV.
    References - Scientific background
    1. Jin, W. and Lu, Z. (1998) Biochemistry 37, 13291.
    2. Drici, M.D. et al. (2000) Br. J. Pharmacol. 131, 569.
    3. Kitamura, H. et al. (2000) J. Pharmacol. Exp. Therap. 293, 196.
    4. Okada, M. et al. (2020) PLoS ONE 15, e0233815.
    Scientific background

    Tertiapin-RQ (TPN-RQ) is a derivative of Tertiapin (#STT-250), a native toxin originally isolated from the venom of the bee, Apis mellifera.  Tertiapin blocks a range of inward-rectifier K+ channels (Kir), in particular ROMK1 (Kir1.1) and GIRK (Kir3 family)1. Tertiapin also inhibits acetylcholine induced K+ currents in mammalian cardiomyocytes2,3. Compared to Tertiapin, TPN-RQ contains an Arg substitution at Ile-8 and the oxidation-liable Met-13 is substituted with a Gln residue. Similar to Tertiapin, TPN-RQ blocks ROMK1 and GIRK channels4.

    Kir channels have diverse physiological functions based on their type and their location. ROMK1 is expressed in the kidneys and brain, but its role in the central nervous system remains unknown. Recent studies suggested that the ROMK1 channel plays a role in mental illness. Consistent with this hypothesis, TPN-RQ suppressed neuronal activity and exhibited an antidepressive and anxiogenic effects in animal models4.

    Target Kir1.1, Kir3.1, Kir3.4 K+ channels
    Peptide Content: 100%
    Last update: 15/06/2021

    Tertiapin-RQ (#STT-180) is a highly pure, synthetic, and biologically active peptide toxin.

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