Identification of β-strand mediated protein–protein interaction inhibitors using ligand-directed fragment ligation
Zsófia Hegedüs, Fruzsina Hóbor, Deborah K. Shoemark, Sergio Celis, Lu‐Yun Lian, Chi H. Trinh, Richard B. Sessions, Thomas A. Edwards, Andrew J. Wilson
Abstract
screening using a fluorescence anisotropy (FA) assay identified peptide hybrid hits with comparable affinity to the GKAP peptide binding sequence. Identified hits were validated using FA, ITC, NMR and X-ray crystallography to confirm selective inhibition of the target PDZ-mediated PPI and mode of binding. These analyses together with molecular dynamics simulations demonstrated the ligands make transient interactions with an unoccupied basic patch through electrostatic interactions, establishing proof-of-concept that this unbiased approach to ligand discovery represents a powerful addition to the armory of tools that can be used to identify PPI modulators.