DNA G-Wire Formation Using an Artificial Peptide is Controlled by Protease Activity

Area of Science:

• Nanobiotechnology
• Supramolecular Chemistry
• Synthetic Biology

Background:

• Guanine nanowires (G-wires) have potential in nanobiotechnology, but controlled formation is challenging.
• External signal-responsive systems are needed to regulate nanostructure assembly.
• Peptide-nucleic acid (PNA) interactions can influence DNA secondary structures.

Purpose of the Study:

• To develop a switchable system for controlling guanine nanowire (G-wire) formation using external signals.
• To investigate the use of a designed peptide and protease for reversible G-wire assembly.
• To explore the potential of this system in nanobiotechnological applications.

Main Methods:

• Design of a peptide incorporating a PNA sequence and a protease substrate.
• Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM) for micro-scale structural analysis.
• Dynamic Light Scattering (DLS), zeta potential, Circular Dichroism (CD), and gel filtration for macro-scale characterization.

Main Results:

• G-rich DNA formed G-wires in the presence of Ca2+.
• The designed peptide disrupted G-wire formation, leading to particle assembly.
• Protease addition and subsequent peptide digestion restored G-wire formation, demonstrating reversibility.

Conclusions:

• A peptide-based system controlled by protease activity enables reversible switching between G-wires and particles.
• The switching mechanism involves a change in DNA secondary structure (G-quadruplex to DNA-PNA hybrid).
• This controllable nanostructure formation holds promise for applications in nanobiotechnology, such as electronic circuits.