Pseudo-complementary PNA actuators as reversible switches in dynamic DNA nanotechnology

Area of Science:

• Nanotechnology
• Molecular Biology
• Supramolecular Chemistry

Background:

• Dynamic DNA nanotechnology relies on structural reorganization of DNA nanoarchitectures.
• Current methods commonly use toehold-mediated strand exchange for DNA reorganization.

Purpose of the Study:

• To introduce a novel, toehold-free switching mechanism for DNA nanoarchitectures.
• To demonstrate the application of peptide nucleic acids (PNAs) as switches in DNA rotaxane systems.

Main Methods:

• Developed a switching process utilizing pseudo-complementary peptide nucleic acids (pcPNAs) and double-strand invasion.
• Synthesized pcPNA monomers and incorporated them into PNA actuator and DNA strands for rotaxane integration.
• Achieved reversible switching between mobile and stationary states by alternating DNA and PNA actuator additions.

Main Results:

• Demonstrated a toehold-free switching mechanism using pcPNAs in a DNA rotaxane architecture.
• Achieved multiple, reversible switching between rotaxane and pseudorotaxane states.
• The switching process is isothermal, occurs at room temperature, and is nearly quantitative.

Conclusions:

• Pseudo-complementary peptide nucleic acids (pcPNAs) offer a new, toehold-free method for dynamic DNA nanotechnology.
• This approach broadens the available orthogonal switching strategies for DNA architectures.
• The developed method opens new avenues for designing complex, responsive DNA nanostructures.