A Case Study on the Keap1 Interaction with Peptide Sequence Epitopes Selected by the Peptidomic mRNA Display

Area of Science:

• Biochemistry
• Molecular Biology
• Drug Discovery

Background:

• Protein-protein interactions (PPIs) are crucial for biological regulation and represent key targets for drug development.
• Despite known PPIs, a vast number of unknown interactions are predicted, necessitating novel discovery methods.
• Current methods for PPI identification have limitations, driving the need for innovative approaches.

Purpose of the Study:

• To introduce a novel peptidomic mRNA display method for identifying novel peptide binders to target proteins.
• To demonstrate the method's efficacy by targeting Kelch-like ECH-associated protein (Keap1).
• To explore the potential for discovering previously unknown PPIs.

Main Methods:

• Utilized an mRNA display system with a total RNA library from diverse human tissues.
• Performed selection against the target protein Kelch-like ECH-associated protein (Keap1).
• Isolated and characterized peptide epitopes with binding affinity to Keap1.

Main Results:

• Identified a peptide epitope from astrotactin-1 (ASTN1) that binds to Keap1.
• The ASTN1 peptide exhibited stronger binding to Keap1 compared to the known Nrf2-derived peptide.
• Demonstrated the rapid identification of consensus binding peptide motifs.

Conclusions:

• The peptidomic mRNA display is a powerful tool for exploring peptide-protein interactions.
• This method facilitates the discovery of novel peptide binders and potential PPIs.
• The approach holds promise for identifying new drug targets and therapeutic strategies.