Direct-to-Biology Enabled Molecular Glue Discovery.

Area of Science:

• Biochemistry
• Chemical Biology
• Drug Discovery

Background:

• Molecular glues are crucial for controlling protein proximity, but their direct screening remains challenging.
• The mechanism involves stabilizing a ternary complex of the glue and two target proteins.
• Identifying fundamental features for function-first screening is key to advancing molecular glue discovery.

Purpose of the Study:

• To differentiate molecular glues from non-glues based on ternary versus binary complex affinities.
• To develop a high-throughput method for discovering novel molecular glues.
• To establish a roadmap for *de novo* molecular glue discovery using kinetic profiling.

Main Methods:

• Leveraging differences in ternary and binary complex affinities to categorize glues.
• Employing high-throughput chemical synthesis and affinity-selection mass spectrometry.
• Utilizing orthogonal assays to validate molecular glue identification through ternary complex stability.

Main Results:

• Successfully identified a molecular glue from over 20,000 crude chemical reaction mixtures.
• Demonstrated that differences in ternary complex stability robustly support glue identification.
• Validated the approach using orthogonal assays confirming the identified compound as a molecular glue.

Conclusions:

• Differences in ternary and binary complex affinities can effectively categorize molecular glues.
• Kinetic profiling of unpurified small molecule mixtures against protein pairs provides a viable roadmap for *de novo* molecular glue discovery.
• This approach significantly advances the ability to screen for and discover novel molecular glues.