5EIH

mAChE-TZ2/PA5 complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.175 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Steric and Dynamic Parameters Influencing In Situ Cycloadditions to Form Triazole Inhibitors with Crystalline Acetylcholinesterase.

Bourne, Y.Sharpless, K.B.Taylor, P.Marchot, P.

(2016) J.Am.Chem.Soc. 138: 1611-1621

  • DOI: 10.1021/jacs.5b11384
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Ligand binding sites on acetylcholinesterase (AChE) comprise an active center, at the base of a deep and narrow gorge lined by aromatic residues, and a peripheral site at the gorge entry. These features launched AChE as a reaction vessel for in situ ...

    Ligand binding sites on acetylcholinesterase (AChE) comprise an active center, at the base of a deep and narrow gorge lined by aromatic residues, and a peripheral site at the gorge entry. These features launched AChE as a reaction vessel for in situ click-chemistry synthesis of high-affinity TZ2PA6 and TZ2PA5 inhibitors, forming a syn-triazole upon cycloaddition within the gorge from alkyne and azide reactants bound at the two sites, respectively. Subsequent crystallographic analyses of AChE complexes with the TZ2PA6 regioisomers demonstrated that syn product association is accompanied by side chain reorganization within the gorge, freezing-in-frame a conformation distinct from an unbound state or anti complex. To correlate inhibitor dimensions with reactivity and explore whether in situ cycloaddition could be accelerated in a concentrated, crystalline template, we developed crystal-soaking procedures and solved structures of AChE complexes with the TZ2PA5 regioisomers and their TZ2/PA5 precursors (2.1-2.7 Å resolution). The structures reveal motions of residue His447 in the active site and, unprecedentedly, residue Tyr341 at the gorge mouth, associated with TZ2 binding and coordinated with other side chain motions in the gorge that may guide AChE toward a transient state favoring syn-triazole formation. Despite precursor binding to crystalline AChE, coupling of rapid electric field fluctuations in the gorge with proper alignments of the azide and alkyne reactants to form the triazole remains a likely limiting step. These observations point to a prime requirement for AChE to interconvert dynamically between sequential conformations to promote favorable electrostatic factors enabling a productive apposition of the reactants for reactivity.


    Organizational Affiliation

    Department of Chemistry, The Skaggs Institute for Chemical Biology, The Scripps Research Institute , La Jolla, California 92037, United States.,Centre National de la Recherche Scientifique, laboratory Architecture et Fonction des Macromolécules Biologiques, Faculté des Sciences de Luminy , 13288 Marseille cedex 09, France.,Aix-Marseille Université, laboratory Architecture et Fonction des Macromolécules Biologiques, Faculté des Sciences de Luminy , 13288 Marseille cedex 09, France.,Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego , La Jolla, California 92093-0650, United States.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Acetylcholinesterase
A, B
543Mus musculusMutation(s): 0 
Gene Names: Ache
EC: 3.1.1.7
Find proteins for P21836 (Mus musculus)
Go to UniProtKB:  P21836
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ACT
Query on ACT

Download SDF File 
Download CCD File 
A, B
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
PZ5
Query on PZ5

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Download CCD File 
A
5-hept-6-ynyl-6-phenyl-phenanthridin-5-ium-3,8-diamine
C26 H26 N3
WJXZOVZRCNSPKF-UHFFFAOYSA-O
 Ligand Interaction
P6G
Query on P6G

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Download CCD File 
B
HEXAETHYLENE GLYCOL
POLYETHYLENE GLYCOL PEG400
C12 H26 O7
IIRDTKBZINWQAW-UHFFFAOYSA-N
 Ligand Interaction
TZ2
Query on TZ2

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Download CCD File 
A, B
~{N}-(2-azidoethyl)-1,2,3,4-tetrahydroacridin-9-amine
C15 H17 N5
ANJRGTMSMVLPLB-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.175 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 79.500α = 90.00
b = 112.978β = 90.00
c = 226.504γ = 90.00
Software Package:
Software NamePurpose
BUSTERrefinement
REFMACphasing
XDSdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2016-01-20
    Type: Initial release
  • Version 1.1: 2016-02-17
    Type: Database references