Population Shift Mechanism for Partial Agonism of AMPA Receptor (Biophysical Journal)

AMPA ionotropic glutamate receptors mediate fast excitatory neurotransmission in the central nervous system and their dysfunction is associated with neurological diseases. Glutamate binding to ligand-binding domains (LBDs) of AMPA receptors induces channel opening in the transmembrane domains of the receptors. The T686A mutation reduces glutamate efficacy, so that the glutamate behaves as a partial agonist. The crystal structures of wild-type and mutant LBDs are very similar and cannot account for the observed behavior.