3rn8 | pdb_00003rn8
Crystal Structure of iGluR2 Ligand Binding Domain and Symmetrical Carboxyl Containing Potentiator
Structural highlights
FunctionGRIA2_HUMAN Receptor for glutamate that functions as ligand-gated ion channel in the central nervous system and plays an important role in excitatory synaptic transmission. L-glutamate acts as an excitatory neurotransmitter at many synapses in the central nervous system. Binding of the excitatory neurotransmitter L-glutamate induces a conformation change, leading to the opening of the cation channel, and thereby converts the chemical signal to an electrical impulse. The receptor then desensitizes rapidly and enters a transient inactive state, characterized by the presence of bound agonist. In the presence of CACNG4 or CACNG7 or CACNG8, shows resensitization which is characterized by a delayed accumulation of current flux upon continued application of glutamate.[1] Publication Abstract from PubMedAt the dimer interface of the extracellular ligand-binding domain of AMPA receptors a hydrophilic pocket is formed that is known to interact with two classes of positive allosteric modulators, represented by cyclothiazide and the ampakine CX614. Here we present structural and functional data on two new positive allosteric modulators of AMPA receptors, CMPDA and CMPDB. Crystallographic data show that these compounds bind within the modulator-binding pocket, and that substituents of each compound overlap with distinct moieties of cyclothiazide and CX614. The goals of the present study were to determine 1) the degree of modulation by CMPDA and CMPDB of AMPA receptor deactivation and desensitization; 2) whether these compounds are splice isoform-selective; and, 3) whether predictions of mechanism of action could be inferred by comparing molecular interactions between the ligand binding domain and each compound to those of cyclothiazide and CX614. CMPDB was found to be more isoform-selective than would be predicted from initial binding assays. Importantly, these new compounds are both more potent and more efficacious, and also may be more clinically relevant, than the previously described AMPA receptor modulators. Structural and Functional Analysis of Two New Positive Allosteric Modulators of GluA2 Desensitization and Deactivation.,Timm DM, Benveniste M, Weeks AM, Nisenbaum ES, Partin KM Mol Pharmacol. 2011 May 4. PMID:21543522[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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