Abstract
Optimization of fragment hits toward high-affinity lead compounds is a crucial aspect of fragment-based drug discovery (FBDD). In the current study, we have successfully optimized a fragment by growing into a ligand-inducible subpocket of the binding site of acetylcholine-binding protein (AChBP). This protein is a soluble homologue of the ligand binding domain (LBD) of Cys-loop receptors. The fragment optimization was monitored with X-ray structures of ligand complexes and systematic thermodynamic analyses using surface plasmon resonance (SPR) biosensor analysis and isothermal titration calorimetry (ITC). Using site-directed mutagenesis and AChBP from different species, we find that specific changes in thermodynamic binding profiles, are indicative of interactions with the ligand-inducible subpocket of AChBP. This study illustrates that thermodynamic analysis provides valuable information on ligand binding modes and is complementary to affinity data when guiding rational structure- and fragment-based discovery approaches.
Original language | English |
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Pages (from-to) | 5363-5371 |
Number of pages | 9 |
Journal | Journal of the American Chemical Society |
Volume | 133 |
Issue number | 14 |
DOIs | |
Publication status | Published - 15 Feb 2011 |
Keywords
- Calorimetry
- Carrier Proteins/chemistry
- Crystallography, X-Ray
- Drug Discovery/methods
- Ligands
- Models, Molecular
- Mutagenesis, Site-Directed
- Protein Conformation/drug effects
- Protein Stability/drug effects
- Reproducibility of Results
- Species Specificity
- Surface Plasmon Resonance
- Thermodynamics
- Tyrosine