A highly constrained nucleic acid analog based on α-l-threosamine

Area of Science:

• Medicinal Chemistry
• Nucleic Acid Chemistry
• Biotechnology

Background:

• Chemically modified oligonucleotides (ONs) are gaining attention as therapeutic agents due to enhanced properties.
• Developing novel nucleic acid analogs is crucial for advancing oligonucleotide-based therapies.

Purpose of the Study:

• To design and characterize a new nucleic acid analog, cTNA, based on α-l-threosamine.
• To evaluate the hybridization properties of cTNA-containing oligonucleotides.

Main Methods:

• Synthesis of cTNA-based oligonucleotides.
• Hybridization assays with complementary RNA and DNA.
• Quantum chemical calculations to investigate structural and energetic properties.

Main Results:

• cTNA features a dual constrained structure with a bridged sugar moiety and a shorter phosphoramidate backbone.
• Oligonucleotides containing cTNA unexpectedly demonstrated reduced binding affinity compared to natural oligonucleotides.
• Quantum chemical calculations suggested an unfavorable relative nucleobase orientation in cTNA.

Conclusions:

• The novel cTNA analog, despite its constrained structure, does not enhance binding affinity.
• The unfavorable nucleobase orientation is a key factor limiting the hybridization efficiency of cTNA.
• Further research is needed to optimize nucleic acid analogs for therapeutic applications.