ω-Grammotoxin SIA

ω-Theraphotoxin-Gr1a, ω-TRTX-Gr1a, ω-GrTx SIA, ω-GsTx SIA, ω-GTX SIA
A Novel Blocker of CaV2.1 (P-type) and CaV2.2 (N-type) Channels
    Cat #: G-450
    Alternative Name ω-Theraphotoxin-Gr1a, ω-TRTX-Gr1a, ω-GrTx SIA, ω-GsTx SIA, ω-GTX SIA
  • Lyophilized Powder
  • Bioassay Tested
  • Origin Natural peptide isolated from Grammostola rosea (Chilean rose tarantula).
    MW: 4109.7 Da.
    Purity: >98% (HPLC)
    Effective concentration 50-500 nM.
    Sequence DCVRFWGKCSQTSDCCPHLACKSKWPRNICVWDGSV.
    Modifications Disulfide bonds between Cys2-Cys16, Cys9-Cys21 and Cys15-Cys30.
      • ω-Grammotoxin SIA
    Molecular formula C177H263N53O49S6.
    CAS No.: 152617-90-8.
    Activity ω-Grammotoxin SIA is a potent inhibitor of both P- and N-type Ca2+ channels1.
      • Lampe R.A. et al. (1993) Mol. Pharmacol. 44, 451.
    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.
      • ω-Grammotoxin SIA
        Alomone Labs ω-Grammotoxin SIA inhibits CaV2.2 channels heterologously expressed in Xenopus oocytes.
        Left: Time course showing current amplitude in response to 100 ms test pulse to 0 mV delivered every 10 seconds before, during (bar) and after application of 500 nM ω-Grammotoxin SIA (#G-450), which inhibits 60% of N-type currents. The box denoting +100 mV shows the period in which similar pulses to +100 mV were delivered in order to partially relieve the inhibition. Right: The current traces were taken at the indicated positions.
    References - Scientific background
    • 1. Lampe R.A. et al. (1993) Mol. Pharmacol. 44, 451.
    • 2. Piser T.M. et al. (1995) Mol. Pharmacol. 48, 131.
    • 3. McDonough, S.I. et al. (1997) Mol. Pharmacol52, 1095.
      • ω-Grammotoxin SIA is a native toxin isolated from venom of the South American Tarantula spider Grammostola spatulata. ω-Grammotoxin SIA potently inhibits both CaV2.1 (P-type) and CaV2.2 (N-type) Ca2+ channels by altering the voltage-dependence of channel gating. ω-Grammotoxin SIA caused a concentration-dependent and virtually complete inhibition of K+-evoked influx of 45Ca2+ into either rat or chick brain synaptosomes.1 ω-Grammotoxin SIA at 1 µM, a maximally effective concentration, blocked 52% of IBa in cultured rat hippocampal neurons.2 A concentration of >50 nM toxin completely inhibited Ca2+ currents in Purkinje neurons (predominantly, P-type channels) and in sympathetic neurons (predominantly, N-type channels).3
    Target P-type and N-type Ca2+ channels
    Net Peptide Content: 100%
    Last update: 04/11/2019

    ω-Grammotoxin SIA (#G-450) is a highly pure, natural, and biologically active peptide toxin.

    For research purposes only, not for human use