4HJ2

Crystal Structure Analysis of GSTA1-1 in complex with chlorambucil


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.215 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

The interaction of the chemotherapeutic drug chlorambucil with human glutathione transferase A1-1: kinetic and structural analysis.

Karpusas, M.Axarli, I.Chiniadis, L.Papakyriakou, A.Bethanis, K.Scopelitou, K.Clonis, Y.D.Labrou, N.E.

(2013) Plos One 8: e56337-e56337

  • DOI: 10.1371/journal.pone.0056337

  • PubMed Abstract: 
  • Glutathione transferases (GSTs) are enzymes that contribute to cellular detoxification by catalysing the nucleophilic attack of glutathione (GSH) on the electrophilic centre of a number of xenobiotic compounds, including several chemotherapeutic drug ...

    Glutathione transferases (GSTs) are enzymes that contribute to cellular detoxification by catalysing the nucleophilic attack of glutathione (GSH) on the electrophilic centre of a number of xenobiotic compounds, including several chemotherapeutic drugs. In the present work we investigated the interaction of the chemotherapeutic drug chlorambucil (CBL) with human GSTA1-1 (hGSTA1-1) using kinetic analysis, protein crystallography and molecular dynamics. In the presence of GSH, CBL behaves as an efficient substrate for hGSTA1-1. The rate-limiting step of the catalytic reaction between CBL and GSH is viscosity-dependent and kinetic data suggest that product release is rate-limiting. The crystal structure of the hGSTA1-1/CBL-GSH complex was solved at 2.1 Å resolution by molecular replacement. CBL is bound at the H-site attached to the thiol group of GSH, is partially ordered and exposed to the solvent, making specific interactions with the enzyme. Molecular dynamics simulations based on the crystal structure indicated high mobility of the CBL moiety and stabilization of the C-terminal helix due to the presence of the adduct. In the absence of GSH, CBL is shown to be an alkylating irreversible inhibitor for hGSTA1-1. Inactivation of the enzyme by CBL followed a biphasic pseudo-first-order saturation kinetics with approximately 1 mol of CBL per mol of dimeric enzyme being incorporated. Structural analysis suggested that the modifying residue is Cys112 which is located at the entrance of the H-site. The results are indicative of a structural communication between the subunits on the basis of mutually exclusive modification of Cys112, indicating that the two enzyme active sites are presumably coordinated.


    Organizational Affiliation

    Physics Laboratory, Department of Science, Agricultural University of Athens, Athens, Greece.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Glutathione S-transferase A1
A, B
217Homo sapiensMutation(s): 0 
Gene Names: GSTA1
EC: 2.5.1.18
Find proteins for P08263 (Homo sapiens)
Go to Gene View: GSTA1
Go to UniProtKB:  P08263
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
LZ6
Query on LZ6

Download SDF File 
Download CCD File 
A, B
L-gamma-glutamyl-S-(2-{[4-(3-carboxypropyl)phenyl](2-chloroethyl)amino}ethyl)-L-cysteinylglycine
Chlorambucil-Glutathione Conjugate
C24 H35 Cl N4 O8 S
BQVGPQFUMPRIMA-OALUTQOASA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
LZ6Kd: 2950000 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.215 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 99.000α = 90.00
b = 93.530β = 93.91
c = 51.180γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CNSrefinement
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-03-27
    Type: Initial release