This product is freeze dried. All water molecules have been removed.
Every lot is tried & tested in a relevant biological assay.
Lampe R.A. et al. (1993) Mol. Pharmacol. 44, 451.
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.
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
ω-Grammotoxin SIA (#G-450) is a highly pure, natural, and biologically active peptide toxin.