Perfluoroarene-based peptide macrocycles that inhibit the Nrf2/Keap1 interaction

Area of Science:

• Biochemistry
• Molecular Biology
• Drug Discovery

Background:

• The Nrf2/Keap1 pathway regulates cellular defense mechanisms against oxidative stress and inflammation.
• Inhibition of the Nrf2/Keap1 interaction is a therapeutic strategy to activate Nrf2 and elicit anti-inflammatory effects.
• Previous peptide inhibitors mimicking the Keap1 active site showed high affinity but lacked cell permeability.

Purpose of the Study:

• To design and synthesize novel peptide inhibitors targeting the Nrf2/Keap1 interaction.
• To enhance the binding affinity and explore the potential for intracellular activity of modified peptides.

Main Methods:

• Peptide design incorporating a perfluoroalkyl-bridging group for enhanced conformational constraint.
• Amino acid substitution (glutamic acid to proline) to modulate peptide structure and interactions.
• Biochemical assays to determine the inhibition constant (Ki) of the Nrf2/Keap1 binding interaction.

Main Results:

• A novel peptide was synthesized with a K_i of 6.1 nM for the Nrf2/Keap1 binding interaction, demonstrating potent inhibitory capacity.
• The modified peptide structure, despite high binding affinity, did not exhibit significant intracellular activity.
• Structural modifications aimed at improving affinity did not confer the desired cellular efficacy.

Conclusions:

• The developed peptide represents a significant advancement in targeting the Nrf2/Keap1 interaction with high affinity.
• Further research is required to overcome the limitations in intracellular activity for potential therapeutic development.
• Optimization of peptide design for cell permeability and intracellular efficacy remains a critical challenge.