Overview
- Balsara, R. et al. (2012) Neuropharmacology 62, 2227.
Alomone Labs Conantokin G efficiently inhibits NMDA receptors expressed in Xenopus oocytes.Representative NR1A/NR2B current elicited in Mg2+-free bath solution by continuous co-application of 1 µM glutamate and 100 µM glycine (black bar), and fully inhibited by 50 µM Conantokin G (#STC-666) application (red bar). Membrane potential was held at -60 mV and current was recorded by two-electrode voltage-clamp.
The figure was kindly provided by Prof. Shai Berlin, Ruth and Bruce Rappaport Faculty of Medicine, Technion, Israel.
Conantokin G is a 17 amino acid peptide toxin originally isolated from Conus geographus venom. The toxin acts as a selective antagonist of the GluN2B, a subunit of NMDA receptors1-3. Conantokin G structure includes γ-carboxiglutamic acid which coordinates binding of 4 calcium ions1,2.
Conantokin G has IC50 values of 0.48 µM in hippocampal and cortical neurons, and 0.1 µM in Xenopus oocytes expressing the GluN1–GluN2B subunits1. In vitro studies of neuronal cultures have revealed anti-apoptotic properties of Conantokin G. In animal models, Conantokin G has been successfully tested as an anti-convulsant and as an anti-analgesic agent.
NMDA receptors belong to the family of ionotropic receptors coactivated by glutamate and glycine. They play a central role in neuronal plasticity, learning, and memory3.
