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==CRYSTAL STRUCTURE OF the MACHE-Y337A mutant in complex with soaked TZ2PA6 ANTI-SYN inhibitors== | |||
<StructureSection load='2xuq' size='340' side='right'caption='[[2xuq]], [[Resolution|resolution]] 2.70Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2xuq]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2XUQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2XUQ 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]] 2.7Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=P6G:HEXAETHYLENE+GLYCOL'>P6G</scene>, <scene name='pdbligand=TZ4:3,8-DIAMINO-6-PHENYL-5-[6-[1-[2-[(1,2,3,4-TETRAHYDRO-9-ACRIDINYL)AMINO]ETHYL]-1H-1,2,3-TRIAZOL-4-YL]HEXYL]-PHENANTHRIDINIUM'>TZ4</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=2xuq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2xuq OCA], [https://pdbe.org/2xuq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2xuq RCSB], [https://www.ebi.ac.uk/pdbsum/2xuq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2xuq ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/ACES_MOUSE ACES_MOUSE] Terminates signal transduction at the neuromuscular junction by rapid hydrolysis of the acetylcholine released into the synaptic cleft. | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The active center of acetylcholinesterase (AChE), a target site for competitive inhibitors, resides centrosymmetric to the subunit at the base of a deep, narrow gorge lined by aromatic residues. At the gorge entry, a peripheral site encompasses overlapping binding loci for noncompetitive inhibitors, which alter substrate access to the gorge. The click-chemistry inhibitor TZ2PA6 links the active center ligand, tacrine, to the peripheral site ligand, propidium, through a biorthogonal reaction of an acetylene and an azide that forms either a syn1 or an anti1 triazole. Compared with wild-type mouse AChE, a Tyr337Ala mutant displays full catalytic activity, albeit with 2-3 orders of magnitude higher affinities for the TZ2PA6 syn1 and anti1 regioisomers, reflected in low femtomolar K(d) values, diffusion-limited association, and dissociation half-times greater than 1 month and 1 week, respectively. Three structures of each of the co-crystallized syn1 and anti1 complexes of the Tyr337Ala mutant were solved at three distinct times of crystal maturation, consistent with or exceeding the half-lives of the complexes in solution, while crystalline complexes obtained from soaked Tyr337Ala crystals led to picturing "freshly formed" complexes. The structures, at 2.55-2.75A resolution, reveal a range of unprecedented conformations of the bound regioisomers, not observed in the wild-type AChE complexes, associated with concerted positional rearrangements of side chains in the enzyme gorge. Moreover, time-dependent conformational remodeling of the crystalline complexes appears to correlate with the dissociation half-times of the solution complexes. Hence, for the tight-binding TZ2PA6 inhibitors, the initial complexes kinetically driven in solution slowly form more stable complexes governed by thermodynamic equilibrium and observable in mature crystals. | |||
Conformational Remodeling of Femtomolar Inhibitor-Acetylcholinesterase Complexes in the Crystalline State.,Bourne Y, Radic Z, Taylor P, Marchot P J Am Chem Soc. 2010 Nov 19. PMID:21090615<ref>PMID:21090615</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 2xuq" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Acetylcholinesterase 3D structures|Acetylcholinesterase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Mus musculus]] | |||
[[Category: Bourne Y]] | |||
[[Category: Marchot P]] | |||
[[Category: Radic Z]] | |||
[[Category: Taylor P]] | |||
Latest revision as of 13:39, 20 December 2023
CRYSTAL STRUCTURE OF the MACHE-Y337A mutant in complex with soaked TZ2PA6 ANTI-SYN inhibitorsCRYSTAL STRUCTURE OF the MACHE-Y337A mutant in complex with soaked TZ2PA6 ANTI-SYN inhibitors
Structural highlights
FunctionACES_MOUSE Terminates signal transduction at the neuromuscular junction by rapid hydrolysis of the acetylcholine released into the synaptic cleft. Publication Abstract from PubMedThe active center of acetylcholinesterase (AChE), a target site for competitive inhibitors, resides centrosymmetric to the subunit at the base of a deep, narrow gorge lined by aromatic residues. At the gorge entry, a peripheral site encompasses overlapping binding loci for noncompetitive inhibitors, which alter substrate access to the gorge. The click-chemistry inhibitor TZ2PA6 links the active center ligand, tacrine, to the peripheral site ligand, propidium, through a biorthogonal reaction of an acetylene and an azide that forms either a syn1 or an anti1 triazole. Compared with wild-type mouse AChE, a Tyr337Ala mutant displays full catalytic activity, albeit with 2-3 orders of magnitude higher affinities for the TZ2PA6 syn1 and anti1 regioisomers, reflected in low femtomolar K(d) values, diffusion-limited association, and dissociation half-times greater than 1 month and 1 week, respectively. Three structures of each of the co-crystallized syn1 and anti1 complexes of the Tyr337Ala mutant were solved at three distinct times of crystal maturation, consistent with or exceeding the half-lives of the complexes in solution, while crystalline complexes obtained from soaked Tyr337Ala crystals led to picturing "freshly formed" complexes. The structures, at 2.55-2.75A resolution, reveal a range of unprecedented conformations of the bound regioisomers, not observed in the wild-type AChE complexes, associated with concerted positional rearrangements of side chains in the enzyme gorge. Moreover, time-dependent conformational remodeling of the crystalline complexes appears to correlate with the dissociation half-times of the solution complexes. Hence, for the tight-binding TZ2PA6 inhibitors, the initial complexes kinetically driven in solution slowly form more stable complexes governed by thermodynamic equilibrium and observable in mature crystals. Conformational Remodeling of Femtomolar Inhibitor-Acetylcholinesterase Complexes in the Crystalline State.,Bourne Y, Radic Z, Taylor P, Marchot P J Am Chem Soc. 2010 Nov 19. PMID:21090615[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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