Design And Application Of DNA Tensegrity Nanostructure And Topological Nanostructures

In nature,one of the remarkable characteristics of biomacromolecules is the complexity of their structures.The complexity of the structure plays a vital role in the orderly regulation of the internal environment.Artificial biomacromolecule should have strong functionality and can be customized.The establishment of artificial molecules with a refined structure that can achieve specific functions has always been the goal of scientific research.Compared with inorganic nanomaterials,biomolecules have specific recognition function,which lays the foundation for establishing a definite quantitative relationship among the molecules in the system.The currently development of gene chips,DNA molecular machines and DNA computers based on DNA nanotechnology are all driven by the specific recognition of coding sequence in the structure.Based on structural DNA nanotechnology,the tensegrity threedimensional rigid structures,DNA reconfigurable topological nanostructure were constructed,and make it used as a dynamic molecular platform for DNA double-track logic gate in the circuit.1.Using the needle threading method,two DNA strands were used to construct tensegrity triangle and tensegrity square DNA nanostructure.Based on the prestress of tensegrity structure itself,it can maintain its own rigidity well.The construction of rigid structure can be realized by using folding path with zero crossing number in the experiment process.Significantly,the AFM tip is used to apply external force to the structure,and the tensegrity triangular structure can still maintain a good configuration when tensioned.This is consistent with the rigid theory of geometric constraints.2.Three kinds of DNA Origami nanostructures were constructed,which its topological properties can be converted.The reconfiguration of the three kinds of DNA nanostructures all started from the two-dimensional(2D)plane.The cross-shaped and wide-flanged 2D DNA nanostructures were designed by using the DAE structural primitive,and the T-shaped 2D DNA nanostructures were constructed by using the DPE and DAE composite structural primitive.The conversion from a two-dimensional plane structure to a three-dimensional space structure is completed through the layered selfassembly mode.Through the cutting operation of DNA strand displacement,three three-dimensional DNA nanostructures with distinct topological differences can be transformed into Euclidean plane geometry with the same topological properties.3.The topologically variable DNA origami structure constructed based on the "foldfold-release" design strategy can be used in the architecture of molecular computing networks.Three DNA origami topologies,Cross-link,Deformed figure-eight and Mobius short,are used as the circuit platform for DNA molecular calculations.Circuit elements with different functions can be pre-integrated on the surface of DNA origami to create addressable nanoscale information flow paths.Due to the topological variability of the DNA origami nanostructure,the information flow transmission path loaded on its surface will change,so the function of the dual-track logic circuit can be switched.Meanwhile,during the experiment,it was discovered that the threedimensional DNA topological nanostructure with non-orientable curved surface has a higher degree of information interaction function.