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Tertiapin LQ

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

Cat #: STT-220
Alternative Name Tertiapin LQ
Lyophilized Powder yes
  • Bioassay Tested
  • Origin Synthetic peptide
    MW: 2428 Da
    Purity: >98% (HPLC)
    Effective concentration 100 nM.
    Modifications Disulfide bonds between Cys3-Cys14 and Cys5-Cys18. C-terminal Lys21 amidation.
    Molecular formula C106H179N33O24S4.
    Activity Tertiapin-LQ is a selective blocker of Kir1.1 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 Tertiapin-LQ inhibits Kir1.1 channels heterologously expressed in Xenopus oocytes.
      Alomone Labs Tertiapin-LQ inhibits Kir1.1 channels heterologously expressed in Xenopus oocytes.
      A continuous current trace of Kir1.1 channels was recorded at a holding potential of -80 mV. Channel activation was achieved by a continuous application of high K+ containing solution (indicated by the bottom bar). Kir1.1 currents are inhibited by increasing concentrations of Tertiapin-LQ (#STT-220), applied for 2 min each (100 nM, 200 nM, 500 nM and 1µM, as indicated by the top green bars).
    References - Scientific background
    1. Ramu, Y. et al. (2008) Proc Natl Acad Sci U.S.A. 105, 10774.
    2. Xu, X. et al. (1993) Proteins 17, 124.
    3. Jin, Wand Lu, Z. (1998) Biochemistry 37, 13291.
    4. Kitamura, H. et al. (2000) J. Pharmacol. Exp. Therap. 293, 196.
    Scientific background

    Inward-rectifier K+ (Kir) channels play many important biological roles and are emerging as important therapeutic targets. Tertiapin (TPN), a toxin present in honey bee venom (Apis mellifera) inhibits certain subtypes of inward-rectifier K+ channels1. TPN is a highly compact peptide of 21 residues. Its C-terminal portion (histidine 12 to glycine 19) adopts an α-helical structure, whereas the N-terminal half acquires extended conformations. Two pairs of disulfide bonds help to hold the two parts together2. Tertiapin inhibits ROMK1 (Kir1.1) and G-protein-gated channel (GIRK1/4) (Kir3.1/3.4) channels with IC50 values of 8.6 and 2.0 nM respectively and is selective over Kir2.1 channels3. In accordance, it was shown to inhibit acetylcholine induced K+ currents in mammalian cardiomyocytes4.

    Tertiapin-LQ is a tertiapin-Q derivative that blocks Kir1.1 channels. It does so by binding to the external vestibule of the K+-conduction pore that is formed by the linker between the first and second transmembrane (M1-M2) segments1.

    Target Kir1.1, Kir3.1, Kir3.4 K+ channels
    Peptide Content: 100%
    Last update: 19/10/2022

    Tertiapin-LQ (#STT-220) is a highly pure, synthetic, and biologically active peptide toxin.

    For research purposes only, not for human use



    Product citations
    1. Estrada, J.A. and Kaufman, M.P. (2018) Am. J. Physiol. 314, R693.


    Scientific Background

    Shipping and Ordering information