Poster abstracts

Poster number 50 submitted by Joshua Johnson

Control of DNA Origami Mechanisms and Assemblies via Gold Nanoparticles

Joshua Johnson (Biophysics), Abhilasha Dehankar (Chemical Engineering), Jessica Winter (Chemical Engineering), Carlos Castro (Mechanical and Aerospace Engineering)

Abstract:
A major direction of research in DNA origami nanotechnology is the folding of dynamic nanostructures with motion that mimics macroscale machines [1]. One application of these nanomachines is the organization and control of other components such as proteins or nanoparticles (NPs). The ability to control arrays of NPs provides a promising approach to modulate their interactions and the material properties that emerge from those interactions. Dynamic DNA nanostructures are typically actuated via the addition of DNA “fuel” strands that form or displace connections to reconfigure a structure [2]. DNA origami mechanisms actuated in this manner usually require several minutes to several hours to transition between states. The goal of this work is to demonstrate a novel actuation method employing nanoparticles as control elements in a thermal actuation scheme for both rapid and reversible control of composite DNA origami-NP devices and assemblies. Using a DNA origami hinge mechanism, we have included overhangs along the interior surfaces of each hinge arm which bind to a DNA-conjugated gold NP to latch the hinge into a closed configuration. By varying NP binding position and size, the angular distributions can be tuned to specific ranges. Varying the NP binding affinity of the bottom arm relative to the top arm allows for actuation of the hinge via DNA melting without releasing the NP entirely. Steady state thermal actuation as well as temperature-jump assays show rapid, reversible, and tunable actuation based on the length of latching strands. In T-jump assays we found that NP-hinges actuate on the timescale of seconds, which is only limited by the rate of heating of the bulk solution. We have also polymerized hinges into dynamic assemblies, which retain their ability to thermally actuate using nanoparticle as control elements. The polymer hinges in combination with effective actuation schemes will establish a basis for rapidly reconfigurable higher-order assemblies.

References:
1. Marras, A.E., et al., Programmable motion of DNA origami mechanisms. Proceedings of the National Academy of Sciences of the United States of America, 2015. 112(3): p. 713-718.
2. Kuzyk, A., et al., Reconfigurable 3D plasmonic metamolecules. Nature materials, 2014. 13(9): p. 862-866.

Keywords: DNA origami, nanoparticles, nanomachines