An Inward Rectifier K+ Channel Blocker Conjugated to the Fluorescent Dye ATTO-488
    Cat #: STT-170-AG
  • Lyophilized Powder
  • Bioassay Tested
  • Origin Synthetic peptide
    MW: 3195.5 Da.
    Purity: >95%
    Effective concentration 50-200 nM.
    Modifications Disulfide bonds between Cys3-Cys14, Cys5-Cys18. Lys21 - C-terminal amidation.
    Label ATTO-488. ATTO dyes are characterized by strong absorption (high extinction coefficient), high fluorescence quantum yield, and high photo-stability. ATTO-488 maximum absorption is 501 nm and maximum fluorescence is at 523 nm. The fluorescence is excited most efficiently in the 480 - 515 nm range. This label is analogous to the well known dye fluorescein isothiocyanate (FITC) and can be used with filters typically used to detect FITC. The extent of labeling is one molecule of dye per molecule of Tertiapin-Q.
    • Tertiapin-Q-ATTO-488
    Activity Tertiapin-Q blocks a range of inward rectifier K+ channels (Kir), in particular ROMK1 and GIRK, but with no effect on Kir2 family members1,2. In addition, it was shown to inhibit acetylcholine induced K+ currents in the heart3,4.
    1. Jin, W. and Lu, Z. (1998) Biochemistry 37, 13291.
    2. Jin, W. et al. (1999) Biochemistry 38, 14294.
    3. Drici, M.D. et al. (2000) Br. J. Pharmacol131, 569.
    4. Kitamura, H. et al. (2000) Pharmacol. Exp. Therap293, 196.
    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. Avoid exposure to light.
    Solubility Any aqueous buffer. Centrifuge all product preparations before use (10000 x g 5 min). Avoid exposure to light. The product is lyophilized in 0.5 ml conical vial.
    Storage of solutions Up to two weeks at 4°C or three months at -20°C. Avoid exposure to light.
    Our bioassay
    • Tertiapin-Q-ATTO-488
      Alomone Labs Tertiapin-Q-ATTO-488 inhibits Kir3.2 channels heterologously expressed in Xenopus oocytes.
      A continuous current trace recorded at a holding potential of -80 mV. Kir3.2 currents are downward reflections activated by high Kcontaining solution. While activated, 50 nM and 100 nM of Tertiapin-Q-ATTO-488 (#STT-170-AG) were applied for 2 min (indicated as bars).
    • Tertiapin-Q-ATTO-488
      Alomone Labs Tertiapin-Q-ATTO-488 binds GIRK1/4-Cherry transfected HEK293T cells.
      Transfected cells were incubated in the presence of 200 nM Tertiapin-Q-ATTO-488 (#STT-170-AG). The labeled toxin accumulates on the membrane surface after 26 sec. No binding is achieved in untransfected cells (data not shown).
      The pictures are a kind gift from the lab of Prof. Eithan Reuveny, Weizmann Institute, Israel.
    References - Scientific background
    1. Jin, W. and Lu, Z. (1998) Biochemistry 37, 13291.
    2. Drici, M.D. et al. (2000) Br. J. Pharmacol131, 569.
    3. Kitamura, H. et al. (2000) J. Pharmacol. Exp. Ther293, 196.
    4. Peleg, S. et al. (2002) Neuron 33, 87.
    5. Kanjhan, R. et al. (2005) J. Pharmacol. Exp. Ther314, 1353.
    Scientific background

    Tertiapin, the native toxin, was originally isolated from European honey bee Apis mellifera venom. Native and synthetic Tertiapin blocks a range of inward rectifier K+ channels (Kir), in particular ROMK1 (Kir1.1, IC50 = 2 nM) and GIRK (Kir3 family, IC50 for the Kir3.1/3.4 heteromer was 8.6 nM) but with no effect on the Kir2 family member1. In accordance, it was shown to inhibit acetylcholine induced K+ currents in mammalian cardiomyocytes2,3.

    Tertiapin-Q is a derivative of Tertiapin in which Met13 is substituted by a Gln residue. However, unlike native Tertiapin, Tertiapin-Q is non-oxidizable and therefore is more stable4.

    Tertiapin-Q inhibits the above-mentioned channels with similar affinities and also inhibits Ca2-activated large conductance BK-type K+ channels in a concentration and voltage-dependent manner5.

    Target Kir1.1, Kir3.2 Kchannels
    Net Peptide Content: 100%
    Image & Title

    Tertiapin-Q-ATTO-488Double staining of GIRK2 channels in substantia nigra pars compacta using Tertiapin-Q-ATTO-488 and Guinea pig Anti-GIRK2 (Kir3.2) Antibody.Rat brain sections were first incubated with 33 nM Tertiapin-Q-ATTO-488 (#STT-170-AG), (green). The same sections were incubated with Guinea pig Anti-GIRK2 (Kir3.2) Antibody (#AGP-013). A. Tertiapin-Q-ATTO-488 binding appears in profiles of substantia nigra pars compacta (SNC) neurons (arrows). B. GIRK2 staining (red) is detected in profiles of SNC neurons (arrows). C. Merge of the two images demonstrates co-staining of GIRK2 channels by Tertiapin-Q-ATTO-488 and by Guinea pig Anti-GIRK2 (Kir3.2) Antibody. DAPI staining (blue) is used to stain nuclei.

    Last update: 24/01/2020

    Tertiapin-Q-ATTO-488 (#STT-170-AG) is a highly pure, synthetic, and biologically active conjugated peptide toxin.

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    For research purposes only, not for human use
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