1zgc

Crystal Structure of Torpedo Californica Acetylcholinesterase in Complex With an (RS)-Tacrine(10)-Hupyridone Inhibitor.

spinqualitylabelsall models 1zgc, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1zgc is a 2 chain structure with sequence from Torpedo californica. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: A2E, NAG Related: 1zgb Activity: Acetylcholinesterase, with EC number 3.1.1.7 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT, TOPSAN Function [ACES_TORCA] Terminates signal transduction at the neuromuscular junction by rapid hydrolysis of the acetylcholine released into the synaptic cleft. May be involved in cell-cell interactions. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Recently, alkylene-linked heterodimers of tacrine (1) and 5-amino-5,6,7,8-tetrahydroquinolinone (2, hupyridone) were shown to exhibit higher acetylcholinesterase (AChE) inhibition than either monomeric 1 or 2. Such inhibitors are potential drug candidates for ameliorating the cognitive decrements in early Alzheimer patients. In an attempt to understand the inhibition mechanism of one such dimer, (RS)-(+/-)-N-9-(1,2,3,4-tetrahydroacridinyl)-N'-5-[5,6,7,8-tetrahydro-2'(1 'H)-quinolinonyl]-1,10-diaminodecane [(RS)-(+/-)-3] bisoxalate, the racemate was soaked in trigonal Torpedo californica AChE (TcAChE) crystals, and the X-ray structure of the resulting complex was solved to 2.30 A resolution. Its structure revealed the 1 unit bound to the "anionic" subsite of the active site, near the bottom of the active-site gorge, as seen for the 1/TcAChE complex. Interestingly, only the (R)-enantiomer of the 2 unit was seen in the peripheral "anionic" site (PAS) at the top of the gorge, and was hydrogen-bonded to the side chains of residues belonging to an adjacent, symmetry-related AChE molecule covering the gorge entrance. When the same racemate was soaked in orthorhombic crystals of TcAChE, in which the entrance to the gorge is more exposed, the crystal structure of the corresponding complex revealed no substantial enantiomeric selectivity. This observation suggests that the apparent enantiomeric selectivity of trigonal crystals of TcAChE for (R)-3 is mainly due to crystal packing, resulting in preferential binding of one enantiomeric inhibitor both to its "host" enzyme and to its neighbor in the asymmetric unit, rather than to steric constraints imposed by the geometry of the active-site gorge. Crystal packing mediates enantioselective ligand recognition at the peripheral site of acetylcholinesterase.,Haviv H, Wong DM, Greenblatt HM, Carlier PR, Pang YP, Silman I, Sussman JL J Am Chem Soc. 2005 Aug 10;127(31):11029-36. PMID:16076210 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also AChE inhibitors and substrates Acetylcholinesterase 3D structures Torpedo Californica Acetylcholinesterase in complex with an (R)-Tacrine-(10)-Hupyridone inhibitor User:Dawn M. Wong

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