Single-strand-targeted triplex formation: stability, specificity and RNase H activation properties

Area of Science:

• Molecular Biology
• Biochemistry
• Oligonucleotide Chemistry

Background:

• Conventional antisense and antigene oligonucleotides (oligos) are used for nucleic acid targeting.
• Improving the binding affinity and specificity of oligos is crucial for their therapeutic and diagnostic applications.

Purpose of the Study:

• To design and characterize novel foldback triplex-forming oligos (FTFOs).
• To evaluate the binding affinity and specificity of FTFOs against single-stranded DNA/RNA targets.
• To compare FTFOs with conventional oligos.

Main Methods:

• Design of FTFOs with Watson-Crick and Hoogsteen hydrogen bonding domains.
• Thermal denaturation studies to assess binding affinity.
• DNase I hydrolysis and electrophoretic mobility shift assays to confirm triplex formation.
• Evaluation of sequence specificity through dual recognition mechanisms.

Main Results:

• FTFOs demonstrated increased binding affinity compared to conventional oligos.
• The addition of a Hoogsteen domain enhanced target binding.
• Foldback triplex formation was confirmed by biochemical assays.
• FTFOs exhibited superior sequence specificity due to dual Watson-Crick and Hoogsteen base pairing.
• DNA-based FTFOs showed preference for DNA homopurine targets.

Conclusions:

• FTFOs represent a promising class of oligonucleotides with enhanced affinity and specificity.
• The dual hydrogen bonding domains contribute to improved target recognition.
• FTFOs have potential applications in nucleic acid-based technologies.