Analysis of Loops that Mediate Protein-Protein Interactions and Translation into Submicromolar Inhibitors

Area of Science:

• Biochemistry and Structural Biology
• Computational Biology and Cheminformatics
• Drug Discovery and Medicinal Chemistry

Background:

• Effective strategies exist for mimicking alpha-helix and beta-strand protein epitopes, yielding inhibitors for certain protein-protein interactions (PPIs).
• Generalizable strategies for translating loop epitopes into PPI inhibitors remain underdeveloped.
• Loop epitopes are crucial mediators of many PPIs, presenting a significant challenge in drug discovery.

Purpose of the Study:

• To develop general computational and experimental strategies for designing inhibitors against loop-mediated PPIs.
• To identify and characterize
• To validate the developed strategies by creating inhibitors for a specific PPI.
• To uncover druggable targets within the vast landscape of loop-mediated PPIs.

Main Methods:

• Utilized the LoopFinder program to identify
• Developed data-driven criteria for scoring loop-mediated PPIs.
• Employed unbiased clustering to identify common structural motifs in hot loops.
• Implemented a diversity-oriented strategy for rapid production and evaluation of cyclized loop inhibitors.
• Applied the strategy to the stonin2-Eps15 PPI.

Main Results:

• Identified diverse sets of
• Established criteria for scoring PPIs mediated by loops, revealing potentially druggable interactions.
• Uncovered common structural features among hot loops.
• Successfully generated submicromolar inhibitors for the stonin2-Eps15 PPI.
• Developed a potent inhibitor that mimics the native epitope and is well-structured in aqueous solution.

Conclusions:

• The developed computational and experimental strategies enable the design of inhibitors for loop-mediated PPIs.
• This approach provides a pathway to target previously intractable PPIs.
• The study highlights the potential of targeting loop epitopes for therapeutic intervention.