Copper(II)-Controlled Molecular Glue for Mismatched DNA

Area of Science:

• Supramolecular Chemistry
• Molecular Biology
• Chemical Sensing

Background:

• DNA hybridization is crucial for molecular biology and diagnostics.
• Controlling DNA hybridization with external stimuli remains a challenge.
• Mismatches typically destabilize DNA duplexes, hindering controlled hybridization.

Purpose of the Study:

• To investigate the use of a bis-naphthalene macrocycle for inducing hybridization in DNA strands with thymine-thymine mismatches.
• To develop a reversible DNA switching system using metal-ion coordination.
• To create a fast fluorescent two-state DNA switch.

Main Methods:

• Isothermal hybridization experiments using DNA strands with T:T mismatches.
• Addition of a bis-naphthalene macrocycle (2,7-BisNP-NH) to promote hybridization.
• Reversal of hybridization using copper(II) salts to form a non-DNA-binding metal complex.
• Monitoring hybridization state changes via fluorescence.

Main Results:

• The bis-naphthalene macrocycle successfully induced isothermal hybridization of DNA strands containing three T:T mismatches.
• Addition of Cu(II) ions disrupted the macrocycle-DNA complex, leading to DNA strand separation.
• The system demonstrated a rapid, reversible, two-state fluorescence switch based on DNA hybridization.
• The metal complex formation effectively sequestered Cu(II), releasing the macrocycle and restoring DNA hybridization.

Conclusions:

• Bis-naphthalene macrocycles can facilitate hybridization of imperfect DNA sequences.
• Metal-ion-triggered dissociation offers a viable strategy for reversible control of supramolecular DNA assemblies.
• This work presents a promising platform for developing responsive DNA-based molecular switches and sensors.