3TKD

Crystal structure of the GluA2 ligand-binding domain (S1S2J-L483Y-N754S) in complex with glutamate and cyclothiazide at 1.45 A resolution

Summary for 3TKD

• Entry DOI: 10.2210/pdb3tkd/pdb
• Related: 1LB9 1LBB 1LBC 3H6T 3IL1
• Descriptor: GLUTAMATE RECEPTOR 2, GLUTAMIC ACID, CYCLOTHIAZIDE, ... (6 entities in total)
• Functional Keywords: ampa receptor ligand-binding domain, glua2 s1s2j-l483y-n754s, cyclothiazide, allosteric modulation, membrane protein
• Biological source: Rattus norvegicus (rat); More
• Cellular location: Cell membrane; Multi-pass membrane protein: P19491
• Total number of polymer chains: 2
• Total formula weight: 60423.97

Authors

Krintel, C.,Frydenvang, K.,Gajhede, M.,Kastrup, J.S. (deposition date: 2011-08-26, release date: 2011-09-21, Last modification date: 2024-10-30)

Primary citation

Krintel, C.,Frydenvang, K.,Olsen, L.,Kristensen, M.T.,de Barrios, O.,Naur, P.,Francotte, P.,Pirotte, B.,Gajhede, M.,Kastrup, J.S.
Thermodynamics and structural analysis of positive allosteric modulation of the ionotropic glutamate receptor GluA2.
Biochem.J., 441:173-178, 2012

PubMed Abstract: Positive allosteric modulators of the ionotropic glutamate receptor-2 (GluA2) are promising compounds for the treatment of cognitive disorders, e.g. Alzheimer's disease. These modulators bind within the dimer interface of the LBD (ligand-binding domain) and stabilize the agonist-bound conformation slowing receptor desensitization and/or deactivation. In the present study, we employ isothermal titration calorimetry to determine binding affinities and thermodynamic details of binding of modulators of GluA2. A mutant of the LBD of GluA2 (LBD-L483Y-N754S) that forms a stable dimer in solution was used. The potent GluA2 modulator BPAM-97 was used as a reference compound. Evidence that BPAM-97 binds in the same pocket as the well-known GluA2 modulator cyclothiazide was obtained from X-ray structures. The LBD-L483Y-N754S:BPAM-97 complex has a Kd of 5.6 μM (ΔH=-4.9 kcal/mol, -TΔS=-2.3 kcal/mol; where 1 kcal≈4.187 kJ). BPAM-97 was used in a displacement assay to determine a Kd of 0.46 mM (ΔH=-1.2 kcal/mol, -TΔS=-3.3 kcal/mol) for the LBD-L483Y-N754S:IDRA-21 complex. The major structural factors increasing the potency of BPAM-97 over IDRA-21 are the increased van der Waals contacts to, primarily, Met496 in GluA2 imposed by the ethyl substituent of BPAM-97. These results add important information on binding affinities and thermodynamic details, and provide a new tool in the development of drugs against cognitive disorders.

PubMed: 21895609
DOI: 10.1042/BJ20111221

Experimental method

X-RAY DIFFRACTION (1.45 Å)