DNA Nanostructure Based Functional Protein Regulation And Biosensing

Proteins are indispensable biological macromolecules to maintain the body's normal life activities,there are various of their kinds which participate in almost every process within the cell life and perform a variety of specific functions orderly,such as molecular recognition,transmembrane transport,energy conversion,catalytic reaction and so on.Protein is the mechanic to start the life building and the disorder of protein function will break the body balance and lead to the occurrence of diseases.Therefore,it is very important for human beings to explore the mechanism of these biological macromolecules in order to fight disease.Along with the development of molecular biology and molecular medicine,researches on functional proteins will not only stay at the level of discovery and cognition.The regulation and biosensing of proteins is helpful in intracellular life research as well as clinical disease diagnosis and treatment.Some traditional protein regulation technology,such as gene knock-in and knock out,RNA interference can operate directly at the gene level.They can achieve effective regulation but with a lack of accuracy of time and space.In recent years,the booming development of DNA nanotechnology provides a promising way to solve this problem.DNA nanostructures strictly follow the principle of Watson-Crick bases complementary pairing(A-T,C-G)to form a "bottom-up" predictable assembly.Following this principle,we can design any shape of DNA structure by folding DNA strands in a sequence matching way based on the specific DNA sequences.These structures can provide addressable sites for subsequent modification,which offers an ideal template and platform for us to manipulate some biological macromolecules on the molecular size.Through rational design and assembly of DNA sequences,researchers have already built a variety of DNA nanostructures used in biological molecules assembly,regulation and DNA sensing.In order to further expand the application of DNA nanotechnology and give full play to its advantages of programmability and addressability,we takes the regulation and assembly of functional proteins as the starting point,and takes DNA nanostructures as regulatory tools to conduct the following chapters of researches.In chapter 2,we constructed a controllable DNA nano tweezer,and used fluorescent protein as a model to study the dynamic interaction between proteins.We found that through rational design and optimization of DNA-protein crosslinking conditions,we can use DNA nanostructures to artificially regulate proteins relative spatial position dynamically.In chapter 3,we constructed a DNA nanocage to specifically activate the trans-cleavage activity of CRISPR Cas12 a,and realized the regulation of Cas12 a trans-cleavage activity by adding targets of different sizes.In chapter 4,we constructed an integrated DNA tetrahedron platform for the identification and detection of telomerase with an amplified signal output through catalytic hairpin reaction(CHA).Through preliminary verification of the feasibility of the system,we found that the probe target recognition group and the signal reporting group can respond well to telomerase and the secondary target flare generated by telomerase.Through these above studies,we have proved that DNA nanotechnology does have great potential and advantages in the field of functional protein regulation,and our study will provide new ideas for further exploration of the functional mechanism of proteins.