3I06

Crystal structure of cruzain covalently bound to a purine nitrile


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.10 Å
  • R-Value Free: 0.142 
  • R-Value Work: 0.119 
  • R-Value Observed: 0.120 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Identification and optimization of inhibitors of trypanosomal cysteine proteases: cruzain, rhodesain, and TbCatB.

Mott, B.T.Ferreira, R.S.Simeonov, A.Jadhav, A.Ang, K.K.Leister, W.Shen, M.Silveira, J.T.Doyle, P.S.Arkin, M.R.McKerrow, J.H.Inglese, J.Austin, C.P.Thomas, C.J.Shoichet, B.K.Maloney, D.J.

(2010) J Med Chem 53: 52-60

  • DOI: 10.1021/jm901069a
  • Primary Citation of Related Structures:  
    3I06

  • PubMed Abstract: 
  • Trypanosoma cruzi and Trypanosoma brucei are parasites that cause Chagas' disease and African sleeping sickness, respectively. Both parasites rely on essential cysteine proteases for survival: cruzain for T. cruzi and TbCatB/rhodesain for T. brucei. ...

    Trypanosoma cruzi and Trypanosoma brucei are parasites that cause Chagas' disease and African sleeping sickness, respectively. Both parasites rely on essential cysteine proteases for survival: cruzain for T. cruzi and TbCatB/rhodesain for T. brucei. A recent quantitative high-throughput screen of cruzain identified triazine nitriles, which are known inhibitors of other cysteine proteases, as reversible inhibitors of the enzyme. Structural modifications detailed herein, including core scaffold modification from triazine to purine, improved the in vitro potency against both cruzain and rhodesain by 350-fold, while also gaining activity against T. brucei parasites. Selected compounds were screened against a panel of human cysteine and serine proteases to determine selectivity, and a cocrystal was obtained of our most potent analogue bound to cruzain.


    Organizational Affiliation

    NIH Chemical Genomics Center, National Human Genome Research Institute, National Institutes of Health, 9800 Medical Center Drive, MSC 3370 Bethesda, Maryland 20892-3370, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
CruzipainA215Trypanosoma cruziMutation(s): 0 
EC: 3.4.22.51
Find proteins for P25779 (Trypanosoma cruzi)
Explore P25779 
Go to UniProtKB:  P25779
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
QL2
Query on QL2

Download CCD File 
A
6-[(3,5-difluorophenyl)amino]-9-ethyl-9H-purine-2-carbonitrile
C14 H10 F2 N6
SZYYBVWPURUFRR-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
QL2IC50 :  0.20000000298023224   nM  PDBBind
QL2IC50:  0.20000000298023224   nM  BindingDB
QL2IC50:  10   nM  BindingDB
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.10 Å
  • R-Value Free: 0.142 
  • R-Value Work: 0.119 
  • R-Value Observed: 0.120 
  • Space Group: P 65 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 82.967α = 90
b = 82.967β = 90
c = 101.895γ = 120
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
PHASERphasing
REFMACrefinement
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-12-15
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance