Synthesis of Bicyclic Peptides Using Cyanopyridine-Aminothiol Click Chemistry

Area of Science:

• Medicinal Chemistry
• Biotechnology
• Synthetic Biology

Background:

• Constrained peptides are valuable in drug discovery due to their stability and specific conformations.
• Biocompatible methods for peptide cyclization and stapling are established, but bicyclic peptide generation remains less explored.
• Peptide bicycles offer unique structural properties for therapeutic applications.

Purpose of the Study:

• To develop a biocompatible and accessible method for synthesizing peptide bicycles.
• To address the need for efficient and selective generation of bicyclic peptides.
• To provide a detailed protocol for peptide bicycle synthesis using noncanonical amino acids.

Main Methods:

• Solid-phase peptide synthesis of linear precursors incorporating noncanonical amino acids.
• Utilizing the reactivity of cyanopyridine and 1,2-aminothiol for bicyclization.
• On-resin synthesis of noncanonical amino acids from commercially available building blocks.

Main Results:

• Successful synthesis of peptide precursors capable of forming bicyclic structures.
• Efficient bicyclization in aqueous buffer at physiological pH.
• The protocol is accessible to labs with limited synthetic chemistry resources.

Conclusions:

• A novel, biocompatible strategy for peptide bicycle synthesis has been established.
• The developed method facilitates the generation of constrained peptides for therapeutic development.
• This protocol simplifies the synthesis of complex peptide architectures.