ω-Agatoxin IVA

ω-agatoxin-Aa4a, ω-AGTX-Aa4a, ω-Aga-IVA, ω-agatoxin-4A
A Blocker of P/Q-Type CaV Channels
    Cat #: STA-500
    Alternative Name ω-agatoxin-Aa4a, ω-AGTX-Aa4a, ω-Aga-IVA, ω-agatoxin-4A
  • Lyophilized Powder
  • Bioassay Tested
  • Origin Synthetic peptide
    MW: 5202 Da.
    Purity: >98% (HPLC)
    Effective concentration 20 nM - 1 µM.
    Sequence KKKCIAKDYGRCKWGGTPCCRGRGCICSIMGTNCECKPRLIMEGLGLA.
    Modifications Disulfide bonds between Cys4-Cys20, Cys12-Cys25, Cys19-Cys36 and Cys27-Cys34.
      • ω-Agatoxin IVA
    Molecular formula C217H360N68O60S10.
    CAS No.: 145017-83-0.
    Activity ω-Agatoxin IVA is an antagonist of voltage-sensitive P-type Ca2+ channels1. It blocks neuromuscular transmission presynaptically in a variety of synapses2,3.
    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.
      • ω-Agatoxin IVA
        Alomone Labs ω-Agatoxin-IVA inhibits CaV2.1 currents heterologously expressed in Xenopus oocytes.
        A. Time course of ω-Agatoxin IVA (#STA-500) action on CaV2.1 currents. Maximum current amplitudes were plotted as a function of time. Membrane potential was held at -100 mV and cells were stimulated by a 100 ms voltage ramp to +40 mV. 500 nM ω-Agatoxin IVA were perfused as indicated by the bar (green) during 200 sec application. B. Superimposed examples of CaV2.1 channel current in the absence (control) and presence (green) of 500 nM ω-Agatoxin-IVA (taken from the experiment in A).
        ω-Agatoxin IVA
        Alomone Labs ω-Agatoxin IVA potently inhibits CaV2.1 channel currents expressed in HEK 293 cells.
        CaV2.1 currents were elicited by 40 ms voltage ramp from a holding potential of -100 mV to +60 mV, applied every 10 sec using whole-cell voltage clamp technique. Left: Superimposed traces of CaV2.1 currents under control conditions (black) and following 2 min perfusion with Alomone Labs 200 nM ω-Agatoxin IVA (red). Right: Time course of CaV2.1 peak current amplitude change as a result of the application of 200 nM ω-Agatoxin IVA (duration of perfusion indicated by horizontal bar).
    References - Scientific background
      • Native ω-Agatoxin IVA (ω-Aga-IVA) was originally isolated from Agelenopsis aperta spider venom, and was shown to be a selective blocker of CaV2.1 (P/Q type) channels1. However, the sensitivity depends on the auxiliary b subunit isoform2 and on the splice variant3. Therefore, the effective concentration varies between systems. In accordance, the toxin blocks presynaptic Ca2+ currents and synaptic transmission in a variety of synapses4,5.

        ω-Agatoxin IVA is widely used in electrophysiological measurements of cloned and native channels6,7. It is used to assess the role of CaV2.1 channels in synaptic transmission4. In addition, it was used to map the spatial distribution of CaV2.1 channels in mouse cerebellar and hippocampal brain slices8.

    Target P-type Ca2+ channels
    Net Peptide Content: 100%
    Image & Title ω-Agatoxin IVA
    Alomone Labs ω-Agatoxin IVA blocks CaV2.1 channel in mouse calyx of Held.Calyxes were whole-cell voltage-clamped at -80 mV. Traces were recorded in the presence of 1 mM CaCl2, pharmacological isolation of VGCC subtypes was performed in 2 mM CaCl2. 200 nM ω-Agatoxin IVA (#STA-500) was applied to selectively block CaV2.1.Adapted from Lubbert, M. et al. (2017) eLife 6, e28412. with permission of eLife Sciences.
    Last update: 08/09/2019

    ω-Agatoxin IVA (#STA-500) is a highly pure, synthetic, and biologically active peptide toxin.

    For research purposes only, not for human use
    Citations
      • ω-Agatoxin IVA
        Knockdown of FMRP enhances synaptic vesicle exocytosis in presynaptic terminals of DRG neurons via CaV2.2 channels.
        A and B. vGpH response to 40 AP at 10 Hz from presynaptic terminals of DRG neurons transfected with Ctrl shRNA (A) or FMRP shRNA (B) before and after treatment with ω-Conotoxin GVIA (#C-300) and ω-Agatoxin IVA (#STA-500). Fluorescence intensities were normalized to the peak of a brief application of NH4Cl. C. Normalized vGpH responses to 40 AP at 10 Hz from presynaptic terminals of DRG neurons transfected with Ctrl shRNA (black-filled bar, 100±10.6%, n = 38) or FMRP shRNA (red open bar, 137.0±12.6%, n = 25, P = 0.027). ω-Conotoxin GVIA (ConoTx) reduces Ctrl shRNA and FMRP shRNA responses to a similar level (44.7±4.9%, n = 15 and 41.6±3.3%, n = 24, respectively). ω-Conotoxin GVIA and ω-Agatoxin IVA (AgaTx) application reduces further the responses: Ctrl shRNA = 17.3±3.2%, n = 38, and FMRP shRNA = 18.1±5.0%, n = 27. D. Average vGpH response to a 40 Hz stimulation for 30 s from presynaptic terminals of DRG neurons transfected with Ctrl shRNA (blackfilled squares) or FMRP shRNA (open red squares).
        Adapted from Ferron, L. et al. (2014) with permission of Springer Nature.
      • Mouse α-cells (single cell).
        Dickerson, M.T. et al. (2019) Am. J. Physiol. 316, E646.
      • Rat INS-1 832/12 cells (whole-cell calcium currents).
        Luan, C. et al. (2019) Commun. Biol. 2, 106.
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