Trinucleotide duplex formation inside a confined nanospace under supercooled conditions

Area of Science:

• Supramolecular chemistry
• Nanotechnology
• Biophysics

Background:

• Short nucleotide fragments (<3 base pairs) are energetically unstable but crucial for protein-nucleotide interactions.
• These unstable fragments are considered potential building blocks for artificial supramolecular complexes.
• Understanding their behavior is key to designing novel self-assembling systems.

Purpose of the Study:

• To investigate the duplex formation of 3-mer DNA fragments within confined silica mesopores.
• To explore the stabilization of these DNA duplexes under supercooled conditions (below 273 K).
• To assess the feasibility of using mesopores as a reaction space for low-temperature supramolecular assembly.

Main Methods:

• Utilizing silica mesopores functionalized with a positively charged trimethyl aminopropyl monolayer.
• Loading 3-mer DNA fragments, labeled with donor or acceptor dyes, into the modified mesopores.
• Employing Förster Resonance Energy Transfer (FRET) measurements to analyze DNA hybridization.

Main Results:

• Efficient duplex formation of 3-mer DNA was achieved at 233 K within the confined mesopores.
• FRET measurements confirmed hybridization through at least two Adenine-Thymine (A-T) base pairs.
• Enthalpy changes for duplex formation were similar for both complementary and single-mismatched DNA fragments.

Conclusions:

• Confined mesoscale cavities serve as a novel reaction environment for supramolecular complex formation at low temperatures.
• The study demonstrates the successful stabilization of short DNA duplexes under supercooled conditions.
• This research provides a new strategy for the creation of artificial hydrogen-bonded supramolecular complexes.