P09-07

Construction of dual-responsive circular DNA origami nanoactuator

Ryoya SAKAGUCHI *, Yuki SUZUKI

Department of Applied Chemistry Molecular Biotechnology Laboratory, Mie University
( * E-mail: 424M325@m.mie-u.ac.jp )

The properties and functions of a material depend not only on its molecular composition but also the arrangement of its constituent molecules. A platform that enables the manipulation of the relative positions and postures of multiple molecules with nanoscale precision in two- and three-dimensional space has the potential to facilitate the development of novel materials whose functions can be switched on demand. As such a platform, we here report a construction of DNA origami two-dimensional nanoactuator with a circular shape. The circular DNA origami nanoactuator is designed based on a ringed 6-helix bundle having an intrinsic right-handed twist along its axis. The origami structure comprises repeated units of a transformable module, each containing i-motif (iM)-forming bridge strands. Upon iM formation induced by a pH change, the bridge strands contract, causing the module to bend. The cumulative effect of this bending results in writhing of the circular structure. The modules are also designed to be actuated by the addition of an anti-iM strand, which hybridizes with the iM-forming bridge to form duplex DNA. The stiff duplex DNA forces the modules to bend in the direction opposite to that induced by the iM formation, thereby causing another type of transformation from a relaxed circular to a compacted wavy circular shape. Our study will pave the way for the construction of DNA origami nanomachines and nanodevices that exhibit two-dimensional compression and extension.