5E2I

Acetylcholinesterase Methylene Blue no PEG


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.65 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.197 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

The impact of crystallization conditions on structure-based drug design: A case study on the methylene blue/acetylcholinesterase complex.

Dym, O.Song, W.Felder, C.Roth, E.Shnyrov, V.Ashani, Y.Xu, Y.Joosten, R.P.Weiner, L.Sussman, J.L.Silman, I.

(2016) Protein Sci 25: 1096-1114

  • DOI: 10.1002/pro.2923
  • Primary Citation of Related Structures:  
    5DLP, 5E2I, 5E4T, 5E4J

  • PubMed Abstract: 
  • Structure-based drug design utilizes apoprotein or complex structures retrieved from the PDB. >57% of crystallographic PDB entries were obtained with polyethylene glycols (PEGs) as precipitant and/or as cryoprotectant, but <6% of these report presenc ...

    Structure-based drug design utilizes apoprotein or complex structures retrieved from the PDB. >57% of crystallographic PDB entries were obtained with polyethylene glycols (PEGs) as precipitant and/or as cryoprotectant, but <6% of these report presence of individual ethyleneglycol oligomers. We report a case in which ethyleneglycol oligomers' presence in a crystal structure markedly affected the bound ligand's position. Specifically, we compared the positions of methylene blue and decamethonium in acetylcholinesterase complexes obtained using isomorphous crystals precipitated with PEG200 or ammonium sulfate. The ligands' positions within the active-site gorge in complexes obtained using PEG200 are influenced by presence of ethyleneglycol oligomers in both cases bound to W84 at the gorge's bottom, preventing interaction of the ligand's proximal quaternary group with its indole. Consequently, both ligands are ∼3.0Å further up the gorge than in complexes obtained using crystals precipitated with ammonium sulfate, in which the quaternary groups make direct π-cation interactions with the indole. These findings have implications for structure-based drug design, since data for ligand-protein complexes with polyethylene glycol as precipitant may not reflect the ligand's position in its absence, and could result in selecting incorrect drug discovery leads. Docking methylene blue into the structure obtained with PEG200, but omitting the ethyleneglycols, yields results agreeing poorly with the crystal structure; excellent agreement is obtained if they are included. Many proteins display features in which precipitants might lodge. It will be important to investigate presence of precipitants in published crystal structures, and whether it has resulted in misinterpreting electron density maps, adversely affecting drug design.


    Organizational Affiliation

    Department of Neurobiology, Weizmann Institute of Science, Rehovot, 76100, Israel.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
AcetylcholinesteraseA532Tetronarce californicaMutation(s): 0 
Gene Names: ache
EC: 3.1.1.7
Find proteins for P04058 (Tetronarce californica)
Explore P04058 
Go to UniProtKB:  P04058
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
DME
Query on DME

Download CCD File 
A
DECAMETHONIUM ION
C16 H38 N2
MTCUAOILFDZKCO-UHFFFAOYSA-N
 Ligand Interaction
NAG
Query on NAG

Download CCD File 
A
2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
PEG
Query on PEG

Download CCD File 
A
DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
DMEIC50:  1063   nM  BindingDB
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.65 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.197 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 112.609α = 90
b = 112.609β = 90
c = 136.871γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
PDB_EXTRACTdata extraction
HKL-2000data reduction
SCALAdata scaling
PHASESphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Deposited Date: 2015-10-01 
  • Released Date: 2016-03-30 
  • Deposition Author(s): Dym, O.

Revision History 

  • Version 1.0: 2016-03-30
    Type: Initial release
  • Version 1.1: 2016-06-01
    Changes: Database references
  • Version 1.2: 2019-04-10
    Changes: Data collection, Structure summary
  • Version 1.3: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Data collection, Derived calculations, Structure summary