Redox-Switchable Binding Properties of the ATP-Aptamer

Area of Science:

• Biochemistry and Molecular Biology
• Chemical Biology
• Nanotechnology

Background:

• Aptamers are nucleic acid or peptide molecules that bind to a specific target molecule.
• Developing controllable aptamer systems is crucial for advanced molecular diagnostics and therapeutics.
• Redox-responsive modifications offer a promising avenue for external control over aptamer function.

Purpose of the Study:

• To synthesize and characterize methylene blue-modified ATP-aptamers.
• To investigate the redox-controllable and reversible binding of these aptamers to ATP.
• To understand the influence of redox state on aptamer-ATP binding affinity and specificity.

Main Methods:

• Synthesis of methylene blue-modified ATP-aptamers with varying conjugation sites.
• Binding affinity studies using techniques to measure aptamer-ATP interactions.
• Cyclic voltammetry and chemical redox titrations to control and assess aptamer redox state.
• Molecular dynamics and docking simulations to elucidate structural and energetic aspects of binding.

Main Results:

• Methylene blue modification enhanced ATP-aptamer binding affinity compared to nonmodified aptamers.
• The oxidized aptamer form exhibited micromolar affinity for ATP, while the reduced form showed no binding.
• Demonstrated a complete and reversible 'ON'/'OFF' switching of ATP binding through redox control.

Conclusions:

• A redox-controllable aptamer system with a complete 'ON'/'OFF' switch for ATP binding was successfully developed.
• The conjugation site of the redox label significantly impacts binding affinity.
• This system holds potential for applications requiring externally regulated molecular recognition.