Rational Engineering of Dynamic DNA Systems

摘要

During the past quarter of a century the application of DNA molecules as a scaffold material for constructions in the nanometer range has developed from the design of simple,yet ground-breaking four-armed double-helical junction motifs'11 to the self-assembly of complex structural motifs which serve as building blocks to form large supramolecular constructs.The key property of DNA that makes it so attractive for bottom-up nanotechnology is the extraordinary specificity of the hybridization of single-stranded nucleic acids with their Watson-Crick complements to form stable double helices.Thus,a set of carefully designed oligonucleotides can be programmed to self-assemble into a broad range of diverse superstructures.In addition,reversible transition mechanisms between various stable or metastable states,such as secondary structure conformations,can be engineered into DNA superstructures such that static scaffolds become dynamic nano-devices.Such devices may perform,for example,mechanical work,translate information aggregate and dissociate nanoparticles,or bind and release proteins.While the design of static DNA arrays nowadays increasingly follows systematic rules which allow the retrosynthetic analysis of desired superstructures to obtain suitable sets of oligonucleotides that will form these structures,dynamic DNA devices are usually prepared by individual approaches,which take advantage of various conformational states,transition reactions,and respective triggering stimuli,such as oligonucleotide displacement,changes in ionic strengths or pH values of buffers,or binding of small molecules.