Inhibitor fluorination pattern tunes chemically induced protein dimerization.

Area of Science:

• Biochemistry
• Chemical Biology
• Parasitology

Background:

• Chemically induced dimerization (CID) uses small molecules as molecular glues to regulate protein function.
• Targeting essential enzymes in human pathogenic parasites like Trypanosoma brucei is crucial for drug development.

Purpose of the Study:

• To design and characterize thienopyrimidinone-based inhibitors that induce homodimerization of a Trypanosoma brucei oxidoreductase.
• To investigate the impact of site-specific fluorination on inhibitor properties and induced dimerization affinity.

Main Methods:

• Synthesis of thienopyrimidinone inhibitors with varying fluorination patterns.
• Biophysical techniques including NMR spectroscopy, mass spectrometry, calorimetry, and multi-angle light scattering.
• Molecular dynamics (MD) simulations and functional enzyme assays.

Main Results:

• Thienopyrimidinone inhibitors efficiently promoted homodimerization of the target oxidoreductase via covalent attachment and self-assembly.
• A fluorine walk strategy modulated induced dimer affinity over two orders of magnitude.
• Fluorination patterns influenced enzyme inhibition kinetics and protein-inhibitor interactions.

Conclusions:

• Site-specific fluorination is a powerful tool to modulate protein-protein interactions mediated by small molecules.
• This study provides a framework for designing novel molecular glues for chemical biology and therapeutic applications against parasitic diseases.