Vitamin B₁₂ - Peptide Nucleic Acid Conjugates.

Area of Science:

• Medicinal Chemistry
• Synthetic Biology
• Bacteriology

Background:

• Vitamin B12 (cobalamin) is crucial for mammals and bacteria, with specific cellular uptake pathways.
• Its chemical structure allows for conjugation, making it a potential carrier for delivering molecules into cells.
• Hybrid molecules incorporating vitamin B12 have applications in medicine and diagnostics.

Purpose of the Study:

• To develop synthetic strategies for creating vitamin B12 conjugates with peptide nucleic acid (PNA) oligomers.
• To evaluate the efficacy of these conjugates in delivering PNA into bacterial cells for potential antibacterial use.

Main Methods:

• Synthesis of vitamin B12-PNA conjugates using copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) for covalent linkage.
• Alternative synthesis via reduction-sensitive disulfide bridges.
• Modification of vitamin B12 to incorporate azide or thiol-reactive moieties.
• Testing delivery of PNA into Escherichia coli and Salmonella Typhimurium.

Main Results:

• Successful synthesis of vitamin B12-PNA conjugates through CuAAC and disulfide linkage.
• Demonstrated efficient delivery of antisense PNA into E. coli and S. Typhimurium using vitamin B12 conjugates.
• Overcame the bacterial cell envelope barrier for PNA uptake.

Conclusions:

• Vitamin B12 serves as an effective delivery vehicle for PNA oligomers into bacterial cells.
• Vitamin B12-PNA conjugates show promise for antibacterial therapies and diagnostic tools.
• This strategy opens new avenues for targeting bacterial DNA/RNA with therapeutic oligonucleotides.