- Alomone Labs ω-Conotoxin GVIA inhibits CaV2.2 heterologously expressed in Xenopus oocytes.Left: Time course of ω-Conotoxin GVIA (#C-300) action. Current amplitudes were plotted as a function of the stimulus number. Oocyte membrane potential was held at –100 mV and 100 ms stimulating pulse to 0 mV was delivered every 10 seconds. 20 nM ω-Conotoxin GVIA was perfused in the period marked by the bar. Right: Example traces of N-type currents before and during ω-Conotoxin GVIA application.
ω-Conotoxin GVIA is a synthetic toxin originally isolated from the Conus geographus. ω-Conotoxin GVIA is a specific blocker of CaV2.2 Ca2+ channels. It specifically blocks N-type CaV channels by binding to the CaV2.2 α1 subunit (α1B) and its action is only partially reversible.2,3 In accordance, it inhibits synaptic transmission in many systems.4 It is also reported to antagonize P2X receptors.5 The toxin is used to specifically investigate CaV2.2 channel's contributions (by subtraction of the activity before and during perfusion of the toxin). Alternatively, it is used to eliminate the N-type channel contribution to highlight some other channel or enzyme activity. ω-Conotoxin GVIA was also used to purify the channel protein using immunoprecipitation techniques and to label and localize channels and synapses.6
Alomone Labs ω-Conotoxin GVIA blocks CaV2.2 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. 2 µM ω-Conotoxin GVIA (#C-300) was applied to selectively block CaV2.2.Adapted from Lubbert, M. et al. (2017) eLife 6, e28412. with permission of eLife Sciences.