A Blocker of L-Type CaV Channels
    Cat #: F-700
  • Lyophilized Powder
  • Bioassay Tested
  • Origin Natural peptide isolated from Dendroaspis polylepis polylepis (Black mamba snake).
    MW: 7026 Da.
    Purity: >98% (HPLC)
    Effective concentration 100 nM - 2 ֲµM.
    Modifications Disulfide bonds between Cys3-Cys22, Cys17-Cys39, Cys41-Cys52 and Cys53-Cys58.
    • FS-2
    Molecular formula C297N470N92O86S10.
    CAS No.: 63653-99-6.
    Activity FS-2 is an L-type CaV channel blocker1.
    1. Yasuda, O. et al. (1994) Artery 21, 287.
    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 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
    • FS-2
      Alomone Labs FS-2 inhibits CaV1.2 channels heterologously expressed in Xenopus oocytes. 1 µM FS-2 was also used to inhibit high K+ or glucose-induced L-type Ca2+ influx in RIN B insulinoma cells.
      Left: 500 nM FS-2 (#F-700) inhibits 50% of L-type Cacurrents in Xenopus oocytes across the voltage range.
      Right: Example traces of Ca2+ current responses to depolarization to +20 mV before and during application of FS-2.
    References - Scientific background
    1. Schweitz, H. et al. (1990) Toxicon 28, 847.
    2. Yasuda, O. et al. (1994) Artery 21, 287.
    3. Watanabe, T.X. et al. (1995) Jpn. J. Pharmacol. 68, 305.
    Scientific background

    FS-2 is a natural peptidyl toxin isolated from the Dendroaspis p. polylepsis black mamba venom by a modification of the procedure of Schweitz et al.1 and purified to homogenity. FS-2 is an L-type CaV channel blocker.2 The toxin reduced (±)Bay K8644-induced [Ca2+]in increase, in smooth muscle cells as determined by Ca2+ imaging with Fura-2.2 The IC50 for this effect was 23 nM.

    FS-2 induced relaxation in pre-constricted rat aorta, pulmonary artery and trachea.3 In addition, it inhibited acetylcholine-induced contractions in guinea pig ileum.

    Target L-type Ca2+ channels
    Net Peptide Content: 100%
    Last update: 24/01/2020

    FS-2 (#F-700) is a highly pure, natural, and biologically active peptide toxin.

    For research purposes only, not for human use



    Scientific Background


    Product citations
    1. Copello, J.A. et al. (2007) Am. J. Physiol. 292, C2129.
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