title: Dynamic DNA Nanotubes: Reversible Switching between Single and Double-Stranded Forms, and Effect of Base Deletions.
abstract: DNA nanotubes hold great potential as drug delivery vehicles and as programmable templates for the organization of materials and biomolecules. Existing methods for their construction produce assemblies that are entirely double-stranded and rigid, and thus have limited intrinsic dynamic character, or they rely on chemically modified and ligated DNA structures. Here, we report a simple and efficient synthesis of DNA nanotubes from 11 short unmodified strands, and the study of their dynamic behavior by atomic force microscopy and in situ single molecule fluorescence microscopy. This method allows the programmable introduction of DNA structural changes within the repeat units of the tubes. We generate and study fully double-stranded nanotubes, and convert them to nanotubes with one, two and three single-stranded sides, using strand displacement strategies. The nanotubes can be reversibly switched between these forms without compromising their stability and micron-scale lengths. We then site-specifically introduce DNA strands that shorten two sides of the nanotubes, while keeping the length of the third side. The nanotubes undergo bending with increased length mismatch between their sides, until the distortion is significant enough to shorten them, as measured by AFM and single-molecule fluorescence photobleaching experiments. The method presented here produces dynamic and robust nanotubes that can potentially behave as actuators, and allows their site-specific addressability while using a minimal number of component strands.
authors.affiliation: Department of Chemistry and Centre for Self-Assembled Chemical Structures, McGill University , 801 Sherbrooke Street West, Montreal, H3A 0B8, Canada.
authors.forename: Janane F
authors.initials: JF
authors.lastname: Rahbani
authors.affiliation: Department of Chemistry and Centre for Self-Assembled Chemical Structures, McGill University , 801 Sherbrooke Street West, Montreal, H3A 0B8, Canada.
authors.forename: Amani A
authors.initials: AA
authors.lastname: Hariri
authors.affiliation: Department of Chemistry and Centre for Self-Assembled Chemical Structures, McGill University , 801 Sherbrooke Street West, Montreal, H3A 0B8, Canada.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Cosa
authors.affiliation: Department of Chemistry and Centre for Self-Assembled Chemical Structures, McGill University , 801 Sherbrooke Street West, Montreal, H3A 0B8, Canada.
authors.forename: Hanadi F
authors.initials: HF
authors.lastname: Sleiman
mesh_terms: D004247:DNA / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D036103:Nanotechnology; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*
chemical_list: D004277:DNA, Single-Stranded; D004247:DNA
keywords: DNA nanotechnology; dynamic behavior; nanotubes; single-molecule fluorescence; stimuli responsive