Overview
- White, H.S. et al. (2000) J. Pharmacol. Exp. Ther. 292, 425.
Alomone Labs Conantokin R efficiently inhibits NMDA receptors expressed in Xenopus oocytes.Representative NR1A/NR2A current elicited in Mg2+-free bath solution by a continuous co-application of 2 µM glutamate and 10 µM glycine (black bar). Current is significantly inhibited by 3 µM Conantokin R (#STC-777) application (green bar). Membrane potential was held at -80 mV and current was recorded by two-electrode voltage-clamp.
Conantokin R is a peptide toxin originally isolated from the Conus radiatus (Rayed cone) venom, and preferentially antagonizes GluN2A and GluN2B NMDA receptors1,2,4. Conantokins are a group of short linear peptides (17-27 amino acids) originally isolated from the venom of cone snails. They structurally possess a high degree of alpha-helicity in the presence of divalent cations, and contain gamma-carboxyglutamic acid residues. Four naturally occurring conantokins have been identified and characterized to date, Conantokin G, Conantokin T, Conantokin R, and Conantokin-L1,2.
Conantokins appear to function by inhibiting the spermine/spermidine stimulation of ion flow through the NMDAR channel and different conantokin species present different NMDA receptor subunit specificity3.
NMDR inhibition by conantokins is related to various human pathologies including pain, convulsive disorders, stroke, and Parkinson’s disease. The potential pharmacological selectivity of conantokins, coupled to their efficacy in preclinical disease model and favorable safety profiles, indicate that these peptides represent both novel probes for NMDA receptor function as well as an important class of compounds for continued investigation as human therapeutics1.
