INCREASED NMDA AFFINITY OF THE H780Q MUTANT OF THE NMDA RECEPTOR

A point mutation within the coding sequence of the primary subunit of the N-methyl-D-asparlate (NMDA) subtype of glutamate receptor (glutami ne substitution for histidine at position 780) exhibits a higher affin ity for NMDA than the wild type receptor (EC(50) 5 versus 27 mu M). To our knowledge this is the first point mutation of this ligand-gated i on channel described with higher agonist affinity. This observation ma y help further localize the agonist binding site and help to understan d the heterogeneity of agonist affinity within the glutamate receptor family.