2WU3

CRYSTAL STRUCTURE OF MOUSE ACETYLCHOLINESTERASE IN COMPLEX WITH FENAMIPHOS AND HI-6


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.171 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Crystal Structures of Oxime-Bound Fenamiphos-Acetylcholinesterases: Reactivation Involving Flipping of the His447 Ring to Form a Reactive Glu334-His447-Oxime Triad.

Hornberg, A.Artursson, E.Warme, R.Pang, Y.-P.Ekstrom, F.

(2010) Biochem.Pharm. 79: 507

  • DOI: 10.1016/j.bcp.2009.08.027
  • Primary Citation of Related Structures:  2WU4

  • PubMed Abstract: 
  • Organophosphorus insecticides and nerve agents inhibit the vital enzyme acetylcholinesterase by covalently bonding to the catalytic serine residue of the enzyme. Oxime-based reactivators, such as [(E)-[1-[(4-carbamoylpyridin-1-ium-1-yl)methoxymethyl] ...

    Organophosphorus insecticides and nerve agents inhibit the vital enzyme acetylcholinesterase by covalently bonding to the catalytic serine residue of the enzyme. Oxime-based reactivators, such as [(E)-[1-[(4-carbamoylpyridin-1-ium-1-yl)methoxymethyl]pyridin-2-ylidene]methyl]-oxoazanium dichloride (HI-6) and 1,7-heptylene-bis-N,N'-2-pyridiniumaldoxime dichloride (Ortho-7), restore the organophosphate-inhibited enzymatic activity by cleaving the phosphorous conjugate. In this article, we report the intermolecular interactions between Mus musculus acetylcholinesterase inhibited by the insecticide fenamiphos (fep-mAChE) and HI-6 or Ortho-7 revealed by a combination of crystallography and kinetics. The crystal structures of the two oxime-bound fep-mAChE complexes show that both oximes interact with the peripheral anionic site involving different conformations of Trp286 and different peripheral-site residues (Tyr124 for HI-6 and Tyr72 for Ortho-7). Moreover, residues at catalytic site of the HI-6-bound fep-mAChE complex adopt conformations that are similar to those in the apo mAChE, whereas significant conformational changes are observed for the corresponding residues in the Ortho-7-bound fep-mAChE complex. Interestingly, flipping of the His447 imidazole ring allows the formation of a hydrogen bonding network among the Glu334-His447-Ortho-7 triad, which presumably deprotonates the Ortho-7 oxime hydroxyl group, increases the nucleophilicity of the oxime group, and leads to cleavage of the phosphorous conjugate. These results offer insights into a detailed reactivation mechanism for the oximes and development of improved reactivators.


    Organizational Affiliation

    Swedish Defence Research Agency, Division of CBRN Defence and Security, S-901 82 UmeƄ, Sweden.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ACETYLCHOLINESTERASE
A, B
548Mus musculusGene 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
HI6
Query on HI6

Download SDF File 
Download CCD File 
A, B
4-(AMINOCARBONYL)-1-[({2-[(E)-(HYDROXYIMINO)METHYL]PYRIDINIUM-1-YL}METHOXY)METHYL]PYRIDINIUM
1-(2-HYDROXY-IMINOMETHYLPYRIDINIUM)-1-(4-CARBOXYAMINO)-PYRIDINIUM DIMETHYLETHER
C14 H16 N4 O3
FJZDLOMCEPUCII-UHFFFAOYSA-P
 Ligand Interaction
P6G
Query on P6G

Download SDF File 
Download CCD File 
A
HEXAETHYLENE GLYCOL
POLYETHYLENE GLYCOL PEG400
C12 H26 O7
IIRDTKBZINWQAW-UHFFFAOYSA-N
 Ligand Interaction
NAG
Query on NAG

Download SDF File 
Download CCD File 
A
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
CO3
Query on CO3

Download SDF File 
Download CCD File 
A, B
CARBONATE ION
C O3
BVKZGUZCCUSVTD-UHFFFAOYSA-L
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
SXE
Query on SXE
A, B
L-PEPTIDE LINKINGC8 H19 N2 O5 PSER
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.171 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 78.760α = 90.00
b = 111.230β = 90.00
c = 227.700γ = 90.00
Software Package:
Software NamePurpose
XDSdata reduction
PHENIXrefinement
CCP4phasing
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-10-20
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-07-12
    Type: Advisory, Data collection, Derived calculations