Kristiansen, M.; Kryger, M. B. L.; Zhang, Z.; Voigt, N. V.; Birkedal,V.; Gothelf, K. V.
ChemPlusChem 2012, 77, 636–642, DOI: 10.1002/cplu.201200149
A dynamic linear DNA tile actuator is expanded to three new structures of higher complexity. The original DNA actuator was constructed from a central roller strand which hybridizes with two piston strands by forming two half-crossover junctions. A linear expansion of the actuator is obtained by fusing two actuators of different sequence designs with a third central roller strand. This structure spans 35 nm and its integrity was verified by PAGE analysis. Owing to sequence homology around the crossovers the actuator can obtain 12 different states. The states of the actuator are controlled by a lock strand inserted at one end of the actuator and monitored by Förster resonance energy transfer (FRET) spectroscopy between a fluorophore pair which is located at the other end of the actuator. Two other designs were made where the linear actuator monomer is expanded into two dimensions by forming triangular and quadrilateral actuators. This could be attained by extending the central roller to three or four repeated 32 nucleotide regions that are complementary to the same piston. The triangular and quadrilateral actuators were characterized by PAGE analysis and it was shown that they could be locked in states 0, 5, and 10 and furthermore that they could be switched between the different states by strand displacement reactions.