Читать книгу DNA Origami - Группа авторов - Страница 34

We created a DNA transportation system in which a DNA nanomachine can move along a designed track constructed on DNA origami (Figure 1.11c) [88]. A track consisting of multiple ssDNAs (17 stators) was constructed on a DNA scaffold for observation of the multistep movement of a specific DNA motor strand. When a motor strand hybridizes to the complementary stator, cleavage by a nicking enzyme induces branch migration to move one step forward (Figure 1.11c) [89]. Multistep movement was achieved by the turnover of the enzymatic reactions. AFM imaging of the motor strand indicated a single spot of the duplex on the DNA origami, and one‐directional and time‐dependent movement of the DNA motor strand was observed along the motor track. Furthermore, the movement of the motor strand along the motor track was directly observed by HS‐AFM. The DNA motor moved forward along the motor track in each AFM image, and the distance of the movement of the DNA motor corresponded to the distance between adjacent stators, indicating that the movement occurred stepwise on the track. Furthermore, a complicated system for controlling the direction of the motor movement was designed and constructed using a branched track and controllable blocking strands [90]. The movement of the motor was tracked and induced to one of the final destinations using the programmed instruction.

These complicated mobile systems can only be achieved on a planar DNA origami structure, which can provide a programmed scaffold for construction of the track with predesigned instructions. These are excellent examples of nanoscale molecular systems using the addressability of DNA origami.