Single-Molecule Visualization of the Hybridization and Dissociation of Photoresponsive Oligonucleotides and Their Reversible Switching Behavior in a DNA Nanostructure

摘要

Direct observation of the hybridization and dissociation of a double-stranded DNA at molecular resolution is a challenging and fundamental issue for nanoscience and molecular imaging. Single molecules can show different characteristics, which are hidden when observed in the ensemble state under bulk conditions. Individual molecules can behave heteroge-neously, depending on the physical state of the molecules and the local environment around them. Single enzymes and chemical reactions can now be visualized and analyzed on DNA nanostructures using various analysis methods. Direct visualization of the hybridization and dissociation of a single duplex would be quite fascinating, however, there is currently no method available to observe it under physiological conditions. We have recently developed a single-molecule observation platform for DNA-binding proteins and enzymes and DNA structural changes using a DNA-origami nanostructure and high-speed atomic force microscopy (AFM).