Investigating peptide sequence variations for 'double-click' stapled p53 peptides.

Area of Science:

• Medicinal Chemistry
• Molecular Biology
• Oncology

Background:

• The p53/MDM2 interaction is a critical target for cancer therapy, as inhibiting it can restore tumor suppressor functions.
• Stapled peptides offer enhanced stability and cell permeability compared to linear peptides, making them attractive therapeutic leads.
• Previous efforts focused on hydrocarbon-stapled peptides, but alternative stapling chemistries are being explored.

Purpose of the Study:

• To evaluate the impact of different staple positions and azido amino acid side-chain lengths on the efficacy of double-click stapled p53 peptides.
• To assess the binding affinity of these stapled peptides to MDM2.
• To determine the cellular activity of these novel stapled peptide constructs.

Main Methods:

• Synthesis of p53-based diazidopeptides with variations in staple placement and side-chain length.
• Utilizing a "double-click" chemistry approach for peptide stapling.
• Assessing MDM2 binding affinity using biochemical assays.
• Evaluating cellular activity in cancer cell models.

Main Results:

• Different staple positions and side-chain lengths significantly influenced MDM2 binding and cellular activity.
• The K24R mutation, essential for activity in hydrocarbon-stapled peptides, was found to be unnecessary for the double-click stapled analogues.
• Several double-click stapled peptide variants demonstrated potent inhibition of the p53/MDM2 interaction.

Conclusions:

• Double-click stapled peptides represent a viable and potentially advantageous strategy for targeting the p53/MDM2 interaction in cancer.
• The design of stapled peptides can be optimized by varying staple position and side-chain length to enhance therapeutic potential.
• The findings suggest a new avenue for developing anti-cancer therapeutics by decoupling the requirement for specific mutations found in other stapled peptide designs.