Conantokins inhibit N-methyl-D-aspartate (NMDA) receptors. This toxin is far less potent as an anticonvulsant compound than conantokin-R. It induces sleep-like symptoms in mice. Divalent cations stabilize the toxin the in alpha-helix conformation. Expressed by the venom duct. The mature peptide does not contain cysteine residue. Stabilized by divalent cations. Calcium or magnesium. Belongs to the conotoxin B superfamily.