Construction And Exploration Of Partition DNA Nanostructures

DNA origami structure is a new type of nanostructure that uses DNA as the construction material.It is widely used in research in various fields such as biology,chemistry,physics,materials,sensing,diagnosis,and computing,and has great development potential.At present,although many kinds of patterns can be obtained by relying on DNA self-assembly of DNA origami structure,its internal assembly mechanism has not been fully understood.There is still room for optimization in the construction method of 3D dynamic origami structure,and solving the above problems is helpful to promote the research on the application of origami structure,it is necessary to construct a new type of origami structure and understand the physical and chemical properties of the structure.In this study,based on DNA,using PCR annealing technology to complete the self-assembly of DNA origami structure and characterizing the morphology of origami structure through atomic force microscope imaging technology.And then exploring the basic properties of origami structure from three aspects: thermodynamics,structure splicing and origami arrangement of nanoparticles.The main results are as follows:(1)The construction of a new partitioned three-dimensional origami structure.We used a M13mp18 bacteriophage circular DNA and 168 42 bp staple strands to successfully construct a partitioned six-helix bundle three-dimensional nanotube structure through one-step annealing.The structure includes two forms: linear and circular,and dynamic conformational transitions can occur between the two forms.(2)Thermodynamic study of linear nanotubes.By observing the folding of the origami structure at different temperatures,it is found that the assembly temperature of the staple chain in different regions of the nanotube origami structure is different during the assembly process,but the overall assembly of the structure can be completed when annealed to 50°C;The second low-temperature annealing assembly experiment found that the partitioned linear three-dimensional nanotubes can complete the reconstruction of a single module with a length of 66 nm.(3)Splicing experiment of linear nanotubes.The origami dimer was successfully obtained through secondary assembly annealing by using the complementary of the sticky ends and the incomplete fit of the structure shape.(4)Experiment of circular nanotubes combined with biotin-streptavidin.We selected 6 staple chains as the sites of the composite nanoparticles.By modifying the ends of the elongated staple chains to capture streptavidin,we successfully obtained the origami structure and biotin-streptavidin Composite structure.This research successfully constructed a new type of dynamic partitioned nanotube origami structure.The structure construction method is simple and feasible,saves experimental costs,and enriches the diversity of origami structures;Through the study of the thermodynamic properties of the structure,we understand the self-assembly mechanism of the origami structure,laying a foundation for the composite assembly of suitable low-temperature materials and the origami structure;the origami dimer provides a larger origami addressable space;The experiment of origami composite biotin-streptavidin provides an experimental basis for the functional application research of this structure,which is helpful for the research of origami in biomedicine.