3JSU

Quadruple mutant(N51I+C59R+S108N+I164L) plasmodium falciparum dihydrofolate reductase-thymidylate synthase(PFDHFR-TS) complexed with QN254, NADPH, and dUMP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.206 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Preclinical evaluation of the antifolate QN254, 5-chloro- N'6'-(2,5-dimethoxy-benzyl)-quinazoline-2,4,6-triamine, as an antimalarial drug candidate

Nzila, A.Rottmann, M.Chitnumsub, P.Kiara, S.M.Kamchonwongpaisan, S.Maneeruttanarungroj, C.Taweechai, S.Yeung, B.K.Goh, A.Lakshminarayana, S.B.Zou, B.Wong, J.Ma, N.L.Weaver, M.Keller, T.H.Dartois, V.Wittlin, S.Brun, R.Yuthavong, Y.Diagana, T.T.

(2010) Antimicrob.Agents Chemother. 54: 2603-2610

  • DOI: 10.1128/AAC.01526-09

  • PubMed Abstract: 
  • Drug resistance against dihydrofolate reductase (DHFR) inhibitors-such as pyrimethamine (PM)-has now spread to almost all regions where malaria is endemic, rendering antifolate-based malaria treatments highly ineffective. We have previously shown tha ...

    Drug resistance against dihydrofolate reductase (DHFR) inhibitors-such as pyrimethamine (PM)-has now spread to almost all regions where malaria is endemic, rendering antifolate-based malaria treatments highly ineffective. We have previously shown that the di-amino quinazoline QN254 [5-chloro-N'6'-(2,5-dimethoxy-benzyl)-quinazoline-2,4,6-triamine] is active against the highly PM-resistant Plasmodium falciparum V1S strain, suggesting that QN254 could be used to treat malaria in regions with a high prevalence of antifolate resistance. Here, we further demonstrate that QN254 is highly active against Plasmodium falciparum clinical isolates, displaying various levels of antifolate drug resistance, and we provide biochemical and structural evidence that QN254 binds and inhibits the function of both the wild-type and the quadruple-mutant (V1S) forms of the DHFR enzyme. In addition, we have assessed QN254 oral bioavailability, efficacy, and safety in vivo. The compound displays favorable pharmacokinetic properties after oral administration in rodents. The drug was remarkably efficacious against Plasmodium berghei and could fully cure infected mice with three daily oral doses of 30 mg/kg. In the course of these efficacy studies, we have uncovered some dose limiting toxicity at higher doses that was confirmed in rats. Thus, despite its relative in vitro selectivity toward the Plasmodium DHFR enzyme, QN254 does not show the adequate therapeutic index to justify its further development as a single agent.


    Organizational Affiliation

    Kenya Medical Research Institute/Wellcome Trust Collaborative Research Program, Kilifi, Kenya.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Dihydrofolate reductase-thymidylate synthase
A, B
608Plasmodium falciparumGene Names: DHFR-TS
Find proteins for D9N170 (Plasmodium falciparum)
Go to UniProtKB:  D9N170
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
KA5
Query on KA5

Download SDF File 
Download CCD File 
A, B
5-chloro-N~6~-(2,5-dimethoxybenzyl)quinazoline-2,4,6-triamine
C17 H18 Cl N5 O2
ZQYDKYDSKVGDJP-UHFFFAOYSA-N
 Ligand Interaction
UMP
Query on UMP

Download SDF File 
Download CCD File 
A, B
2'-DEOXYURIDINE 5'-MONOPHOSPHATE
DUMP
C9 H13 N2 O8 P
JSRLJPSBLDHEIO-SHYZEUOFSA-N
 Ligand Interaction
NDP
Query on NDP

Download SDF File 
Download CCD File 
A, B
NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE
C21 H30 N7 O17 P3
ACFIXJIJDZMPPO-NNYOXOHSSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.206 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 58.991α = 90.00
b = 157.375β = 90.00
c = 165.511γ = 90.00
Software Package:
Software NamePurpose
superguidata collection
CNSrefinement
SCALEPACKdata scaling
HKL-2000data reduction
CNSphasing
DENZOdata reduction
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-07-28
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-11-01
    Type: Refinement description