2JGJ

Crystal structure of mouse acetylcholinesterase inhibited by aged methamidophos

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.244 
  • R-Value Work: 0.214 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history. 

Literature

Crystal Structures of Acetylcholinesterase in Complex with Organophosphorus Compounds Suggest that the Acyl Pocket Modulates the Aging Reaction by Precluding the Formation of the Trigonal Bipyramidal Transition State.

Hornberg, A., Tunemalm, A.-K., Ekstrom, F.

(2007) Biochemistry 46: 4815

  • DOI: 10.1021/bi0621361
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    • Organophosphorus compounds (OPs), such as nerve agents and a group of insecticides, irreversibly inhibit the enzyme acetylcholinesterase (AChE) by a rapid phosphorylation of the catalytic Ser203 residue. The formed AChE-OP conjugate subsequently unde ...

    Organophosphorus compounds (OPs), such as nerve agents and a group of insecticides, irreversibly inhibit the enzyme acetylcholinesterase (AChE) by a rapid phosphorylation of the catalytic Ser203 residue. The formed AChE-OP conjugate subsequently undergoes an elimination reaction, termed aging, that results in an enzyme completely resistant to oxime-mediated reactivation by medical antidotes. In this study, we present crystal structures of the non-aged and aged complexes between Mus musculus AChE (mAChE) and the nerve agents sarin, VX, and diisopropyl fluorophosphate (DFP) and the OP-based insecticides methamidophos (MeP) and fenamiphos (FeP). Non-aged conjugates of MeP, sarin, and FeP and aged conjugates of MeP, sarin, and VX are very similar to the noninhibited apo conformation of AChE. A minor structural change in the side chain of His447 is observed in the non-aged conjugate of VX. In contrast, an extensive rearrangement of the acyl loop region (residues 287-299) is observed in the non-aged structure of DFP and in the aged structures of DFP and FeP. In the case of FeP, the relatively large substituents of the phosphorus atom are reorganized during aging, providing a structural support of an aging reaction that proceeds through a nucleophilic attack on the phosphorus atom. The FeP aging rate constant is 14 times lower than the corresponding constant for the structurally related OP insecticide MeP, suggesting that tight steric constraints of the acyl pocket loop preclude the formation of a trigonal bipyramidal intermediate.

    Organizational Affiliation: 

    FOI CBRN Defence and Security, S-901 82 Umeå, Sweden.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ACETYLCHOLINESTERASE
A, B
548Mus musculusMutation(s): 0 
Gene Names: Ache
EC: 3.1.1.7
Find proteins for P21836 (Mus musculus)
Go to UniProtKB:  P21836
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
P6G
Query on P6G
Download SDF File 
Download CCD File 
B
HEXAETHYLENE GLYCOL
POLYETHYLENE GLYCOL PEG400
C12 H26 O7
IIRDTKBZINWQAW-UHFFFAOYSA-N
 Ligand Interaction
AE3
Query on AE3
Download SDF File 
Download CCD File 
A
2-(2-ETHOXYETHOXY)ETHANOL
C6 H14 O3
XXJWXESWEXIICW-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
Modified Residues  2 Unique
IDChainsTypeFormula2D DiagramParent
SVV
Query on SVV
A, B
L-PEPTIDE LINKINGC3 H9 N2 O5 PSER
SVW
Query on SVW
A, B
L-PEPTIDE LINKINGC3 H9 N2 O5 PSER
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.244 
  • R-Value Work: 0.214 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 79.250α = 90.00
b = 111.200β = 90.00
c = 227.360γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
SCALAdata scaling
CCP4phasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-04-17
    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: 2018-01-17
    Type: Data collection