The assembly of a "bipedal walker" and of a "bipedal stepper" using DNA constructs is described. These DNA machines are activated by H+/OH- and Hg2+/cysteine triggers. The bipedal walker is activated on a DNA template consisting of four nucleic acid footholds. The forward "walking" of the DNA on the template track is activated by Hg2+ ions and H+ ions, respectively, using the thymine-Hg2+-thymine complex or the i-motif structure as the DNA translocation driving forces. The backward "walking" is activated by OH- ions and cysteine, triggers that destroy the i-motif or thymine-Hg2+-thymine complexes. Similarly, the "bipedal stepper" is activated on a circular DNA template consisting of four tethered footholds. With the Hg2+/cysteine and H+/OH - triggers, clockwise or anticlockwise stepping is demonstrated. The operation of the DNA machines is followed optically by the appropriate labeling of the walker-foothold components with the respective fluorophores/quenchers units.
- Molecular devices
- Nucleic acid