Structural requirements for activation of the glycine receptor that modulates the N-methyl-D-aspartate operated ion channel.

It has recently been demonstrated that glycine can potentiate several measures of N-methyl-D-aspartate (NMDA)-induced channel opening, including radioligand binding to the PCP receptor. These data suggest that the NMDA/PCP receptor complex may be allosterically modulated by a binding site for glycine. We report here that several other monocarboxylic amino acids enhance NMDA-induced [3H]TCP binding and displace [3H]glycine binding with similar apparent affinities and stereoisomerism. The results are discussed with relation to the structural requirements for compounds to bind to this site.