A Kinetic Scout Approach Accelerates Targeted Protein Degrader Development

Area of Science:

• Biochemistry
• Chemical Biology
• Drug Discovery

Background:

• Bifunctional molecules, including targeted protein degraders, are crucial for gain-of-function pharmacology by inducing proximity.
• Accelerating the identification and optimization of these molecules is a key focus in academia and the pharmaceutical industry.
• Previous work utilized chemical proteomics to map degradable targets and develop predictive models for protein degradability.

Purpose of the Study:

• To develop generalizable chemistry strategies for accelerating the development of new bifunctional degraders.
• To investigate the role of ligand residence time in targeted protein degradation.
• To establish a workflow for mechanistic characterization and optimization of degrader activity.

Main Methods:

• Implementation of lysine-targeted reversible-covalent chemistry to modulate binding kinetics for 25 different protein targets.
• Global proteomics analysis to assess degradation.
• Immunoprecipitation followed by mass spectrometry (IP/MS) to analyze ternary complexes.
• E-STUB assay to evaluate the impact of ligand residence time on degradation.

Main Results:

• Target residence time was identified as a major determinant of degrader activity across diverse targets.
• A minimal set of analogues allowed for rapid and rational tuning of residence time.
• The developed workflow enabled mechanistic characterization of degradation pathways.

Conclusions:

• Ligand residence time is a critical, tunable parameter for optimizing targeted protein degrader efficacy.
• This kinetic tuning strategy significantly accelerates early-stage degrader discovery and optimization.
• The findings provide a rational approach to designing more effective bifunctional degraders.