Competitive antagonism of AMPA receptors by ligands of different classes: crystal structure of ATPO bound to the GluR2 ligand-binding core, in comparison with DNQX.Hogner, A., Greenwood, J.R., Liljefors, T., Lunn, M.L., Egebjerg, J., Larsen, I.K., Gouaux, E., Kastrup, J.S.
(2003) J.Med.Chem. 46: 214-221
- PubMed: 12519060
- DOI: 10.1021/jm020989v
- PubMed Abstract:
- Mechanisms for activation and antagonism of an AMPA-sensitive glutamate receptor: Crystal structures of the GluR2 ligand binding core.
Armstrong, N.,Gouaux, E.
(2000) Neuron 28: 165
- Probing the ligand binding domain of the GluR2 receptor by proteolysis and deletion mutagenesis defines domain boundaries and yields a crystallizable construct.
Chen, G.Q.,Sun, R.,Jin, R.,Gouaux, E.
(1998) Protein Sci. 7: 2623
- Structural basis for AMPA receptor activation and ligand selectivity: Crystal structures of five agonist complexes with the GluR2 ligand binding core.
Hogner, A.,Kastrup, J.S.,Jin, R.,Liljefors, T.,Mayer, M.L.,Egebjerg, J.,Larsen, I.,Gouaux, E.
(2002) J.Mol.Biol. 322: 93
- Mechanism of glutamate receptor desensitization.
Sun, Y.,Olson, R.,Horning, M.,Armstrong, N.,Mayer, M.,Gouaux, E.
(2002) Nature 417: 245
Ionotropic glutamate receptors (iGluRs) constitute a family of ligand-gated ion channels that are essential for mediating fast synaptic transmission in the central nervous system. This study presents a high-resolution X-ray structure of the competiti ...
Ionotropic glutamate receptors (iGluRs) constitute a family of ligand-gated ion channels that are essential for mediating fast synaptic transmission in the central nervous system. This study presents a high-resolution X-ray structure of the competitive antagonist (S)-2-amino-3-[5-tert-butyl-3-(phosphonomethoxy)-4-isoxazolyl]propionic acid (ATPO) in complex with the ligand-binding core of the receptor. Comparison with the only previous structure of the ligand-binding core in complex with an antagonist, 6,7-dinitro-2,3-quinoxalinedione (DNQX) (Armstrong, N.; Gouaux, E. Neuron 2000, 28, 165-181), reveals that ATPO and DNQX stabilize an open form of the ligand-binding core by different sets of interactions. Computational techniques are used to quantify the differences between these two ligands and to map the binding site. The isoxazole moiety of ATPO acts primarily as a spacer, and other scaffolds could potentially be used. Whereas agonists induce substantial domain closures compared to the apo structure, ATPO only induces minor conformational changes. These results are consistent with the hypothesis that domain closure is related to receptor activation. To facilitate the design of novel AMPA receptor antagonists, we present a modified model of the binding site that includes key residues involved in ligand recognition.
Department of Medicinal Chemistry, Royal Danish School of Pharmacy, Universitetsparken 2, DK 2100 Copenhagen, Denmark.