Direct, Competitive Comparison of Linear, Monocyclic, and Bicyclic Libraries Using mRNA Display.

Area of Science:

• Biochemistry
• Molecular Biology
• Drug Discovery

Background:

• Peptide macrocyclization is a key strategy in peptide drug discovery, often leading to improved ligand properties.
• The inherent advantages of cyclization over linear peptides within a diverse library context remain an area of investigation.

Purpose of the Study:

• To investigate whether peptide cyclization offers inherent advantages over linear peptides within a structurally diverse library.
• To analyze the binding affinities and topologies of selected peptides after in vitro selection.
• To assess the impact of protease stability on peptide enrichment.

Main Methods:

• Utilized mRNA display technology to construct a peptide library with varied ring sizes and topologies (monocyclic, bicyclic, linear).
• Performed multiple rounds of in vitro selection against streptavidin.
• Analyzed selected peptide sequences for binding affinities, topologies, and enrichment under protease challenge.

Main Results:

• Identified and characterized peptide binders with different topologies from the diverse library.
• Quantified binding affinities of selected cyclic and linear peptides.
• Assessed the relative enrichment and stability of various peptide topologies when subjected to protease treatment.

Conclusions:

• The study provides insights into the relative abundance of different peptide topologies (cyclic vs. linear) that bind to a target protein.
• The findings contribute to understanding the role of macrocyclization in peptide drug discovery by comparing its performance against linear counterparts in a library setting.