Cat #: G-450
Alternative Name ω-Theraphotoxin-Gr1a, ω-TRTX-Gr1a, ω-GrTx SIA, ω-GsTx SIA, ω-GTX SIA
Lyophilized Powder yes
Origin Natural peptide isolated from Grammostola rosea (Chilean rose tarantula).
MW: 4109.7 Da
Purity: >98% (HPLC)
Effective concentration 50-500 nM.
Sequence DCVRFWGKCSQTSDCCPHLACKSKWPRNICVWDGSV- NH2
Modifications Disulfide bonds between Cys2-Cys16, Cys9-Cys21, and Cys15-Cys30.
V36 - Valine amide.
V36 - Valine amide.
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.
- 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.
Scientific background 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
Peptide Content: 100%
For research purposes only, not for human use
Last Update: 03/09/2023