2AAW

Studies on ligand binding and enzyme inhibition of Plasmodium falciparum glutathione S-transferase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.194 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Plasmodium falciparum glutathione S-transferase--structural and mechanistic studies on ligand binding and enzyme inhibition.

Hiller, N.Fritz-Wolf, K.Deponte, M.Wende, W.Zimmermann, H.Becker, K.

(2006) Protein Sci. 15: 281-289

  • DOI: 10.1110/ps.051891106

  • PubMed Abstract: 
  • Glutathione S-transferase of the malarial parasite Plasmodium falciparum (PfGST) represents a novel class of GST isoenzymes. Since the architecture of the PfGST substrate binding site differs significantly from its human counterparts and there is onl ...

    Glutathione S-transferase of the malarial parasite Plasmodium falciparum (PfGST) represents a novel class of GST isoenzymes. Since the architecture of the PfGST substrate binding site differs significantly from its human counterparts and there is only this one isoenzyme present in the parasite, PfGST is considered a highly attractive target for antimalarial drug development. Here we report the mechanistic, kinetic, and structural characterization of PfGST as well as its interaction with different ligands. Our data indicate that in solution PfGST is present as a tetramer that dissociates into dimers in the presence of glutathione (GSH). Fluorescence spectroscopy shows that in the presence of GSH GST serves as ligandin for parasitotoxic ferriprotoporphyrin IX with a high- and a low-affinity binding site. This is supported by a clear uncompetitive inhibition type. Site-directed mutagenesis studies demonstrate that neither Cys 86 nor Cys 101 contribute to the peroxidase activity of the enzyme, which is thus performed GSH-dependently at the active site. Tyr 9 is responsible for the deprotonation of GSH and Lys 15, but also Gln 71 are involved in GSH binding. We furthermore report the 2.4 A resolution X-ray structure of PfGST cocrystallized with the inhibitor S-hexylglutathione. In comparison with a previously reported structure obtained by crystal soaking, differences occur at the C-terminal end of helix alpha4 and at the S-hexylmoiety of the inhibitor. We furthermore show that, in contrast to previous reports, the antimalarial drug artemisinin is not metabolized by PfGST.


    Organizational Affiliation

    Interdisciplinary Research Center, Justus-Liebig-University, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
glutathione s-transferase
A, C
222Plasmodium falciparum (isolate 3D7)Mutation(s): 0 
Gene Names: GST
EC: 2.5.1.18
Find proteins for Q8ILQ7 (Plasmodium falciparum (isolate 3D7))
Go to UniProtKB:  Q8ILQ7
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
DTL
Query on DTL

Download SDF File 
Download CCD File 
C
L-TREITOL
C4 H10 O4
UNXHWFMMPAWVPI-IMJSIDKUSA-N
 Ligand Interaction
P33
Query on P33

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Download CCD File 
A, C
3,6,9,12,15,18-HEXAOXAICOSANE-1,20-DIOL
HEPTAETHYLENE GLYCOL, PEG330
C14 H30 O8
XPJRQAIZZQMSCM-UHFFFAOYSA-N
 Ligand Interaction
GTX
Query on GTX

Download SDF File 
Download CCD File 
A, C
S-HEXYLGLUTATHIONE
C16 H30 N3 O6 S
HXJDWCWJDCOHDG-RYUDHWBXSA-O
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
GTXKi: 35000 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.194 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 61.170α = 90.00
b = 69.990β = 90.00
c = 123.690γ = 90.00
Software Package:
Software NamePurpose
CNSphasing
XDSdata scaling
CAD4data reduction
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-01-10
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2015-06-10
    Type: Non-polymer description