Glucose-Nucleobase Pseudo Base Pairs: Biomolecular Interactions within DNA

Area of Science:

• Biochemistry
• Molecular Biology
• Synthetic Chemistry

Background:

• Noncovalent forces are fundamental to biomolecular interactions.
• Aminoglycoside-RNA interactions serve as a model for studying sugar-nucleobase recognition.
• Understanding modified nucleic acid structures is crucial for developing novel biomaterials and therapeutics.

Purpose of the Study:

• To investigate the hybridization capabilities of deoxyoligonucleotides incorporating 6-deoxyglucose.
• To determine the base-pairing preferences and structural stability of these modified DNA duplexes.
• To explore the potential of glucose-nucleobase interactions in nucleic acid structures.

Main Methods:

• Synthesis of deoxyoligonucleotides containing a 6-deoxyglucose insertion.
• Hybridization studies to assess duplex formation with complementary DNA strands.
• Structural analysis to evaluate distortions and the integration of 6-deoxyglucose.
• Quantum chemical calculations to predict the stability of glucose-nucleobase pairs.

Main Results:

• Deoxyoligonucleotides with 6-deoxyglucose successfully hybridized with complementary strands.
• A preference for pairing with purine nucleobases, particularly guanine, was observed.
• The resulting double helices exhibited minor local distortions and remained less stable than natural DNA.
• The 6-deoxyglucose moiety formed two hydrogen bonds with guanine, mimicking a purine-pyrimidine geometry.
• Quantum chemical calculations showed glucose-purine pairs possess stability comparable to natural T-A pairs.

Conclusions:

• Incorporation of 6-deoxyglucose into DNA is feasible and allows for hybridization.
• The 6-deoxyglucose-guanine pair represents a novel, stable pairing motif in nucleic acids.
• These findings open avenues for designing modified nucleic acids with unique recognition properties.