2WSL

Aged Form of Human Butyrylcholinesterase Inhibited by Tabun Analogue TA4


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.184 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure-activity analysis of aging and reactivation of human butyrylcholinesterase inhibited by analogues of tabun.

Carletti, E.Aurbek, N.Gillon, E.Loiodice, M.Nicolet, Y.Fontecilla-Camps, J.C.Masson, P.Thiermann, H.Nachon, F.Worek, F.

(2009) Biochem. J. 421: 97-106

  • DOI: 10.1042/BJ20090091
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • hBChE [human BChE (butyrylcholinesterase)] naturally scavenges OPs (organophosphates). This bioscavenger is currently in Clinical Phase I for pretreatment of OP intoxication. Phosphylated ChEs (cholinesterases) can undergo a spontaneous time-dependen ...

    hBChE [human BChE (butyrylcholinesterase)] naturally scavenges OPs (organophosphates). This bioscavenger is currently in Clinical Phase I for pretreatment of OP intoxication. Phosphylated ChEs (cholinesterases) can undergo a spontaneous time-dependent process called 'aging' during which the conjugate is dealkylated, leading to creation of an enzyme that cannot be reactivated. hBChE inhibited by phosphoramidates such as tabun displays a peculiar resistance to oxime-mediated reactivation. We investigated the basis of oxime resistance of phosphoramidyl-BChE conjugates by determining the kinetics of inhibition, reactivation (obidoxime {1,1'-(oxybis-methylene) bis[4-(hydroxyimino) methyl] pyridinium dichloride}, TMB-4 [1,3-trimethylene-bis(4-hydroxyiminomethylpyridinium) dibromide], HLö 7 {1-[[[4-(aminocarbonyl) pyridinio]methoxy]methyl]-2,4-bis-[(hydroxyimino)methyl] pyridinium dimethanesulfonate)}, HI-6 {1-[[[4-(aminocarbonyl) pyridinio] methoxy] methyl]-2-[(hydroxyimino)methyl]pyridinium dichloride monohydrate} and aging, and the crystal structures of hBChE inhibited by different N-monoalkyl and N,N-dialkyl tabun analogues. The refined structures of aged hBChE conjugates show that aging proceeds through O-dealkylation of the P(R) enantiomer of N,N-diethyl and N-propyl analogues, with subsequent formation of a salt bridge preventing reactivation, similarly to a previous observation made on tabun-ChE conjugates. Interestingly, the N-methyl analogue projects its amino group towards the choline-binding pocket, so that aging proceeds through deamination. This orientation results from a preference of hBChE's acyl-binding pocket for larger than 2-atoms linear substituents. The correlation between the inhibitory potency and the N-monoalkyl chain length is related to increasingly optimized interactions with the acyl-binding pocket as shown by the X-ray structures. These kinetics and X-ray data lead to a structure-activity relationship that highlights steric and electronic effects of the amino substituent of phosphoramidate. This study provides the structural basis to design new oximes capable of reactivating phosphoramidyl-hBChE conjugates after intoxication, notably when hBChE is used as pretreatment, or to design BChE-based catalytic bioscavengers.


    Organizational Affiliation

    Unité d'Enzymologie, Département de Toxicologie, Centre de Recherches du Service de Santé des Armées (CRSSA), 24 av des Maquis du Grésivaudan, 38700 La Tronche, France.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CHOLINESTERASE
A
529Homo sapiensMutation(s): 4 
Gene Names: BCHE (CHE1)
EC: 3.1.1.8
Find proteins for P06276 (Homo sapiens)
Go to Gene View: BCHE
Go to UniProtKB:  P06276
Small Molecules
Ligands 8 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
F
Query on F

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A
FLUORIDE ION
F
KRHYYFGTRYWZRS-UHFFFAOYSA-M
 Ligand Interaction
NA
Query on NA

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A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
SO4
Query on SO4

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A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
CL
Query on CL

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A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
FUC
Query on FUC

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A
ALPHA-L-FUCOSE
C6 H12 O5
SHZGCJCMOBCMKK-SXUWKVJYSA-N
 Ligand Interaction
NAG
Query on NAG

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A
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
FUL
Query on FUL

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A
BETA-L-FUCOSE
6-DEOXY-BETA-L-GALACTOSE
C6 H12 O5
SHZGCJCMOBCMKK-KGJVWPDLSA-N
 Ligand Interaction
EFS
Query on EFS

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A
ETHYL DIHYDROGEN PHOSPHATE
C2 H7 O4 P
ZJXZSIYSNXKHEA-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
CSS
Query on CSS
A
L-PEPTIDE LINKINGC3 H7 N O2 S2CYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.184 
  • Space Group: I 4 2 2
Unit Cell:
Length (Å)Angle (°)
a = 154.860α = 90.00
b = 154.860β = 90.00
c = 126.010γ = 90.00
Software Package:
Software NamePurpose
XSCALEdata scaling
XDSphasing
REFMACrefinement
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-09-15
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Version format compliance
  • Version 1.2: 2018-02-28
    Type: Database references, Source and taxonomy