Crystal structure of Trypanothione Reductase from Trypanosoma brucei in complex with inhibitor EP127 (5-{5-[1-(PYRROLIDIN-1-YL)CYCLOHEXYL]-1,3-THIAZOL-2-YL}-1H-INDOLE)
Primary Citation of Related Structures:   4NEV, 4NEW
PubMed Abstract: 
The causative agents of the parasitic disease human African trypanosomiasis belong to the family of trypanosomatids. These parasitic protozoa exhibit a unique thiol redox metabolism that is based on the flavoenzyme trypanothione reductase (TR). TR was identified as a potential drug target and features a large active site that allows a multitude of possible ligand orientations, which renders rational structure-based inhibitor design highly challenging ...
The causative agents of the parasitic disease human African trypanosomiasis belong to the family of trypanosomatids. These parasitic protozoa exhibit a unique thiol redox metabolism that is based on the flavoenzyme trypanothione reductase (TR). TR was identified as a potential drug target and features a large active site that allows a multitude of possible ligand orientations, which renders rational structure-based inhibitor design highly challenging. Herein we describe the synthesis, binding properties, and kinetic analysis of a new series of small-molecule inhibitors of TR. The conjunction of biological activities, mutation studies, and virtual ligand docking simulations led to the prediction of a binding mode that was confirmed by crystal structure analysis. The crystal structures revealed that the ligands bind to the hydrophobic wall of the so-called "mepacrine binding site". The binding conformation and potency of the inhibitors varied for TR from Trypanosoma brucei and T. cruzi.
Organizational Affiliation: 
Laboratorium für Organische Chemie, ETH Zürich, Vladimir-Prelog-Weg 3, 8093 Zurich (Switzerland).