Continuous solid-phase synthesis and disulfide cyclization of peptide-PNA-peptide chimeras

Area of Science:

• Chemical Synthesis
• Bioconjugation Chemistry
• Molecular Engineering

Background:

• Peptide nucleic acids (PNAs) are DNA mimics with potential in diagnostics and therapeutics.
• Disulfide-bridged peptides offer unique structural stability and presentation of ligands.
• Combining PNAs and peptides can lead to novel molecular architectures with enhanced functionalities.

Purpose of the Study:

• To develop a simplified and versatile synthetic strategy for creating multipeptide disulfide-bridged PNA chimeras.
• To explore the feasibility of solid-phase synthesis for these complex constructs.
• To enable the preparation of diverse PNA-peptide conjugates.

Main Methods:

• Utilized Fmoc coupling for the sequential extension of chelator peptides, PNA dodecamers, and disulfide-bridged peptide ligand analogues.
• Performed solid-phase synthesis, with cysteine thiol cyclization occurring either before or after PNA extension.
• Employed a modular approach for constructing the chimeric molecules.

Main Results:

• Successfully synthesized peptide-PNA chimeras using the described Fmoc coupling strategy.
• Demonstrated that disulfide bond formation could be achieved at different stages of the synthesis (pre- or post-PNA extension).
• Validated a simplified synthetic route amenable to generating a variety of disulfide-bridged PNA conjugates.

Conclusions:

• The developed synthetic approach offers a streamlined method for preparing complex peptide-PNA conjugates.
• This strategy facilitates the creation of diverse multipeptide disulfide-bridged PNA chimeras.
• The method holds promise for advancing the synthesis of novel biomolecular constructs.