Exploiting Avidity Effects for the Discovery of Low Affinity Protein-Binding Fragments.

Area of Science:

• Biochemistry
• Medicinal Chemistry
• Drug Discovery

Background:

• Fragment-based drug discovery (FBDD) is crucial for developing pharmaceuticals and probe molecules.
• There is a continuous need for innovative platforms to enhance FBDD efficiency.
• Avidity effects are key to stabilizing weak interactions in molecular recognition.

Purpose of the Study:

• To introduce a novel, cost-effective workflow for fragment-based drug discovery.
• To demonstrate the utility of a bead-based display system for capturing multimeric protein targets.
• To validate the platform for both initial fragment screening and subsequent fragment growth strategies.

Main Methods:

• Utilizing low molecular weight organic molecules displayed on TentaGel beads.
• Exposing bead-displayed fragments to multimeric, fluorescently labeled target proteins (dimeric or tetrameric).
• Employing a simple "pull-down" protocol based on avidity-driven protein capture.

Main Results:

• Beads displaying weak ligands (high μM to low mM KDs) successfully captured multimeric protein targets.
• The platform demonstrated stable protein capture due to avidity effects.
• The workflow proved effective for both fragment discovery and fragment growth screening.

Conclusions:

• The developed platform offers an inexpensive and accessible method for fragment-based drug discovery.
• Avidity-based capture of multimeric proteins on beads is a viable strategy for identifying weak-affinity ligands.
• This platform supports key FBDD strategies, including fragment growth, without requiring specialized infrastructure.