title: Nanoengineering a single-molecule mechanical switch using DNA self-assembly.
abstract: The ability to manipulate and observe single biological molecules has led to both fundamental scientific discoveries and new methods in nanoscale engineering. A common challenge in many single-molecule experiments is reliably linking molecules to surfaces, and identifying their interactions. We have met this challenge by nanoengineering a novel DNA-based linker that behaves as a force-activated switch, providing a molecular signature that can eliminate errant data arising from non-specific and multiple interactions. By integrating a receptor and ligand into a single piece of DNA using DNA self-assembly, a single tether can be positively identified by force-extension behavior, and receptor-ligand unbinding easily identified by a sudden increase in tether length. Additionally, under proper conditions the exact same pair of molecules can be repeatedly bound and unbound. Our approach is simple, versatile and modular, and can be easily implemented using standard commercial reagents and laboratory equipment. In addition to improving the reliability and accuracy of force measurements, this single-molecule mechanical switch paves the way for high-throughput serial measurements, single-molecule on-rate studies, and investigations of population heterogeneity.
authors.affiliation: The Rowland Institute at Harvard, Harvard University, Cambridge, MA, USA.|The Immune Disease Institute/Program in Cellular and Molecular Medicine, Children's Hospital Boston, Boston, MA, USA.|The Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
authors.forename: Ken
authors.initials: K
authors.lastname: Halvorsen
authors.affiliation: The Rowland Institute at Harvard, Harvard University, Cambridge, MA, USA.
authors.forename: Diane
authors.initials: D
authors.lastname: Schaak
authors.affiliation: The Rowland Institute at Harvard, Harvard University, Cambridge, MA, USA.|The Immune Disease Institute/Program in Cellular and Molecular Medicine, Children's Hospital Boston, Boston, MA, USA.|The Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
authors.forename: Wesley P
authors.initials: WP
authors.lastname: Wong
mesh_terms: D004247:DNA / Q000737:chemistry*; D008024:Ligands; D018625:Microscopy, Atomic Force / Q000379:methods*; D036103:Nanotechnology / Q000379:methods
chemical_list: D008024:Ligands; D004247:DNA