Selection of DNA aptamers with two modified bases

Area of Science:

• Biochemistry
• Molecular Biology
• Medicinal Chemistry

Background:

• Nucleic acid aptamers offer limited chemical diversity compared to protein ligands.
• Modifying single bases in aptamers has improved ligand identification success.
• Enhanced physicochemical diversity is crucial for aptamer versatility.

Purpose of the Study:

• To explore the benefits of dual base modifications in DNA aptamers.
• To enhance aptamer affinity, stability, and inhibitory potency.
• To investigate aptamer sequence length and epitope occupancy with dual modifications.

Main Methods:

• Selection of modified DNA aptamers with dual amino-acid-like modifications on pyrimidine bases.
• Utilizing proprotein convertase subtilisin/kexin type 9 as a model protein target.
• Comparative analysis of single vs. dual modified aptamers for affinity, stability, and potency.

Main Results:

• Specific pairwise dual modifications significantly improved aptamer affinity, metabolic stability, and inhibitory potency.
• Doubly modified aptamers were often shorter and occupied nonoverlapping epitopes more frequently.
• Demonstrated superior performance of dual modified aptamers over single modified counterparts.

Conclusions:

• Dual amino-acid-like modifications dramatically enhance DNA aptamer capabilities.
• These advanced aptamers show broad utility in research, diagnostics, and therapeutics.
• Doubly modified aptamers represent a significant advancement in nucleic acid ligand development.