Functional characterization of Tet-AMPA [tetrazolyl-2-amino-3-(3-hydroxy-5-methyl- 4-isoxazolyl)propionic acid] analogues at ionotropic glutamate receptors GluR1-GluR4. The molecular basis for the functional selectivity profile of 2-Bn-Tet-AMPA

Anders A Jensen; Thomas Christesen; Ulrik Bølcho; Jeremy R Greenwood; Giovanna Postorino; Stine B Vogensen; Tommy N Johansen; Jan Egebjerg; Hans Bräuner-Osborne; Rasmus P Clausen

doi:10.1021/jm070532r

Functional characterization of Tet-AMPA [tetrazolyl-2-amino-3-(3-hydroxy-5-methyl- 4-isoxazolyl)propionic acid] analogues at ionotropic glutamate receptors GluR1-GluR4. The molecular basis for the functional selectivity profile of 2-Bn-Tet-AMPA

J Med Chem. 2007 Aug 23;50(17):4177-85. doi: 10.1021/jm070532r. Epub 2007 Aug 2.

Authors

Anders A Jensen¹, Thomas Christesen, Ulrik Bølcho, Jeremy R Greenwood, Giovanna Postorino, Stine B Vogensen, Tommy N Johansen, Jan Egebjerg, Hans Bräuner-Osborne, Rasmus P Clausen

Affiliation

¹ Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark. aaj@farma.ku.dk

PMID: 17672447
DOI: 10.1021/jm070532r

Abstract

Four 2-substituted Tet-AMPA [Tet = tetrazolyl, AMPA = 2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid] analogues were characterized functionally at the homomeric AMPA receptors GluR1i, GluR2Qi, GluR3i, and GluR4i in a Fluo-4/Ca2+ assay. Whereas 2-Et-Tet-AMPA, 2-Pr-Tet-AMPA, and 2-iPr-Tet-AMPA were nonselective GluR agonists, 2-Bn-Tet-AMPA exhibited a 40-fold higher potency at GluR4i than at GluR1i. Examination of homology models of the S1-S2 domains of GluR1 and GluR4 containing 2-Bn-Tet-AMPA suggested four nonconserved residues in a region adjacent to the orthosteric site as possible determinants of the GluR4i/GluR1i selectivity. In a mutagenesis study, doubly mutating M686V/I687A in GluR1i in combination with either D399S or E683A increased both the potency and the maximal response of 2-Bn-Tet-AMPA at this receptor to levels similar to those elicited by the agonist at GluR4i. The dependence of the novel selectivity profile of 2-Bn-Tet-AMPA upon residues located outside of the orthosteric site underlines the potential for developing GluR subtype selective ligands by designing compounds with substituents that protrude beyond the (S)-Glu binding pocket.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aniline Compounds
Animals
Binding Sites
Cell Line
Female
Fluorescent Dyes
Humans
In Vitro Techniques
Isoxazoles / chemistry*
Isoxazoles / pharmacology
Models, Molecular
Mutation
Oocytes / drug effects
Oocytes / physiology
Patch-Clamp Techniques
Propionates / chemistry*
Propionates / pharmacology
Rats
Receptors, AMPA / agonists*
Receptors, AMPA / genetics
Receptors, AMPA / physiology
Sequence Homology, Amino Acid
Stereoisomerism
Structure-Activity Relationship
Tetrazoles / chemistry*
Tetrazoles / pharmacology
Thermodynamics
Xanthenes
Xenopus
alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / analogs & derivatives*
alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / chemistry
alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / pharmacology

Substances

2-amino-3-(3-hydroxy-5-(2-benzyl-2H-5-tetrazolyl)-4-isoxazolyl)propionic acid
Aniline Compounds
Fluo 4
Fluorescent Dyes
Isoxazoles
Propionates
Receptors, AMPA
Tetrazoles
Xanthenes
glutamate receptor ionotropic, AMPA 3
glutamate receptor ionotropic, AMPA 4
alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
glutamate receptor ionotropic, AMPA 2
glutamate receptor ionotropic, AMPA 1