DNA Nanotechnology to Disclose Molecular Events at the Nanoscale and Mesoscale Levels

Abstract

Self-assembly is commonly seen in living systems and plays a central role in the construction of cellular structures and thus influences the functions of organized biological systems in the cell. In molecular science, the precise formation of structures via self-assembly processes attracts attention, because the functions of assembled molecules originate from the precise structure and arrangement of the molecules. The emergence of DNA origami technology allows for the design and construction of a desired DNA structure and size at nanoscales. Precise placement and integration of target molecules into the designed DNA nanostructures enables creation of advanced materials and molecular devices. The DNA origami scaffold can provide an analytical method to elucidate the physical properties of a target molecule and its reaction process when combined with high-speed atomic force microscopy (HS-AFM), which enables direct imaging of dynamic motions of biomolecules in physiological environments at both the subsecond time and nanometer-scale spatial resolutions. In addition, the DNA origami realizes to create designed nanoscale spaces for single-molecule analysis.In this chapter, I describe our achievements using DNA origami systems for visualizing various biochemical reactions including enzyme reactions and DNA structural changes using HS-AFM. Designed nanospace can also be used for the analysis the property of DNA molecules. Artificial systems such as a DNA motor and rotor on the DNA origami and dynamic 3D nanostructure with photochemical switches were created and their movements were observed by HS-AFM. In addition, novel programmed self-assembly systems using DNA origami were created. Dynamic assembly/disassembly of photoresponsive DNA origami structures, the formation of micrometer-sized DNA origami assemblies and further integration of DNA origami into the lattice were directly visualized on lipid bilayers. DNA origami-based molecular nanodevices for plasmonics and molecular delivery systems for cell were also created. These target-orientated molecular systems provide powerful solutions for understanding the physical properties of biomolecules in real-time and with high-resolution to create novel nanomachines and nanodevices which function with nanometer scale precision.