View source for 4u4s


==Crystal structure of the GluA2 ligand-binding domain (S1S2J-L483Y-N754S) in complex with glutamate and BPAM25 at 1.90 A resolution.==
<StructureSection load='4u4s' size='340' side='right'caption='[[4u4s]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4u4s]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4U4S OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4U4S FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=3C1:4-ETHYL-3,4-DIHYDRO-2H-PYRIDO[4,3-E][1,2,4]THIADIAZINE+1,1-DIOXIDE'>3C1</scene>, <scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=GLU:GLUTAMIC+ACID'>GLU</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=PEG:DI(HYDROXYETHYL)ETHER'>PEG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4u4s FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4u4s OCA], [https://pdbe.org/4u4s PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4u4s RCSB], [https://www.ebi.ac.uk/pdbsum/4u4s PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4u4s ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/GRIA2_RAT GRIA2_RAT] 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.<ref>PMID:9351977</ref> <ref>PMID:19265014</ref> <ref>PMID:21172611</ref> <ref>PMID:12501192</ref> <ref>PMID:12015593</ref> <ref>PMID:12872125</ref> <ref>PMID:12730367</ref> <ref>PMID:16192394</ref> <ref>PMID:15591246</ref> <ref>PMID:17018279</ref> <ref>PMID:16483599</ref> <ref>PMID:19946266</ref> <ref>PMID:21317873</ref> <ref>PMID:21846932</ref> 
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== Publication Abstract from PubMed ==
Two 4-ethyl-substituted pyridothiadiazine dioxides belonging to alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor positive allosteric modulators were cocrystallized with the GluA2 ligand binding domain in order to decipher the impact of the position of the nitrogen atom on their binding mode at the AMPA receptors. The latter was found to be very similar to that of previously described benzothiadiazine-type AMPA receptor modulators. The affinity of the two compounds for the receptor was determined by isothermal titration calorimetry. Accordingly, the synthesis and biological evaluation of novel 4-cyclopropyl-substituted pyridothiadiazine dioxides was performed and completed with the synthesis of the corresponding chloro-substituted 4-cyclopropyl-3,4-dihydro-2H-benzothiadiazine 1,1-dioxides. The "8-aza" compound 32 was found to be the most potent pyridothiadiazine-type AMPA receptor potentiator in vitro, whereas the 7-chloro-substituted compound 36c emerged as the most promising benzothiadiazine dioxide. Due to proper drug-likeness and low in vivo acute toxicity in mice, 36c was chosen for a more complete preclinical evaluation. The compound was able to easily cross the blood-brain barrier. In an in vivo object recognition test with CD1 mice, oral administration of 36c was found to significantly improve cognition performance at doses as low as 1 mg/kg.

Positive Allosteric Modulators of 2-Amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic Acid Receptors Belonging to 4-Cyclopropyl-3,4-dihydro-2H-1,2,4-pyridothiadiazine Dioxides and Diversely Chloro-Substituted 4-Cyclopropyl-3,4-dihydro-2H-1,2,4-benzothiadiazine 1,1-Dioxides.,Francotte P, Norholm AB, Deva T, Olsen L, Frydenvang K, Goffin E, Fraikin P, de Tullio P, Challal S, Thomas JY, Iop F, Louis C, Botez-Pop I, Lestage P, Danober L, Kastrup JS, Pirotte B J Med Chem. 2014 Nov 17. PMID:25375781<ref>PMID:25375781</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4u4s" style="background-color:#fffaf0;"></div>

==See Also==
*[[Glutamate receptor 3D structures|Glutamate receptor 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Rattus norvegicus]]
[[Category: Deva T]]
[[Category: Frydenvang K]]
[[Category: Kastrup JS]]
[[Category: Noerholm AB]]