Thioamide substitution to probe the hydroxyproline recognition of VHL ligands.Soares, P., Lucas, X., Ciulli, A.
(2018) Bioorg Med Chem 26: 2992-2995
- PubMed: 29650462
- DOI: https://doi.org/10.1016/j.bmc.2018.03.034
- Primary Citation of Related Structures:
6FMI, 6FMJ, 6FMK
- PubMed Abstract:
Thioamide substitution influences hydrogen bond and n → π ∗ interactions involved in the conformational stability of protein secondary structures and oligopeptides. Hydroxyproline is the key recognition element of small molecules targeting the von Hippel-Lindau (VHL) E3 ligase, which are of interest as probes of hypoxia signaling and ligands for PROTAC conjugation. We hypothesized that VHL ligands could be a privileged model system to evaluate the contribution of these interactions to protein:ligand complex formation. Herein we report the synthesis of VHL ligands bearing thioamide substitutions at the central hydroxyproline moiety, and characterize their binding by fluorescence polarization, isothermal titration calorimetry, X-ray crystallography and molecular modeling. In spite of a conserved binding mode, the substitution pattern had a pronounced impact on the ligand affinities. Together the results underscore the role of hydrogen bond and n → π ∗ interactions in fine tuning hydroxyproline recognition by VHL.
Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland, UK. Electronic address: email@example.com.