Development of a Multifunctional Benzophenone Linker for Peptide Stapling and Photoaffinity Labelling

Area of Science:

• Chemical Biology
• Medicinal Chemistry
• Molecular Biology

Background:

• Photoaffinity labeling is crucial for identifying protein-ligand interactions and therapeutic targets.
• Developing novel crosslinking reagents is essential for advancing drug discovery and target characterization.

Purpose of the Study:

• To design and synthesize a multifunctional benzophenone linker for photo-crosslinking and peptide stapling.
• To demonstrate the utility of this linker in creating photoreactive stapled peptides for target identification.

Main Methods:

• Synthesis of a novel benzophenone linker with a double-click stapling motif and an alkyne handle.
• Attachment of the benzophenone linker to a p53-derived peptide via the staple linker.
• Application of the photoreactive stapled peptide in crosslinking assays with competing proteins.

Main Results:

• The novel benzophenone linker was successfully synthesized and incorporated into a peptide.
• The resulting photoreactive stapled peptide preferentially crosslinked with MDM2 in a complex protein mixture.
• The linker's alkyne handle facilitated downstream applications like pull-down assays.

Conclusions:

• The multifunctional benzophenone linker is an effective tool for creating photoreactive stapled peptides.
• This approach allows for selective target engagement and can be used to investigate protein-ligand interactions.
• The method holds promise for identifying and characterizing novel therapeutic targets.