Biomolecular Recognition Effect Based On DNA Origami

DNA origami is formed by folding a single-stranded7,249-nucleotide-long DNAgenome of the bacteriophage M13mp18, using more than200synthetic oligonuclotidescalled staple strands. With the help of the atomic force microscope technology, DNAorigami allows us to study biomolecular interactions at a single molecular lever. Combingthe advantages of the two, this plays a very important role in biomolecular recognition anddrug screening. In this paper, we discuss three issues:(1) We researched that what is theaffection of the distance between two DIG molecules to the binding efficiency of DIGantibody. Seven different distances were designed:0nm、6nm、12nm、18nm、24nm、30nm、36nm. Experimental results found that on the distance of two DIG moleculesreach up to30nm, there is no synergistic effect exits between the two DIG molecules.Tremendous effort has been devoted to understanding why HIV so effectively evadesantibody. Accepted explanation include HIV envelope spikes are present at low density. Inother words the distance of two envelope spikes is too far that both Fabs of antibody can’tbind envelope spikes at the same time. Maybe what we found can prove the hypothesis.The intermolecular specific binding efficiency is very important to the recognition.(2) With decorating DIG on designate position of DNA origami, we research theaffection of density of DIG to the binding efficiency with DIG antibody. The experimentalresults show that: the density of the DIG in the origami has a direct impact to the bindingefficiency between DIG and DIG antibody. The higher density of DIG means strongerbinding ability.(3) With decorating aptamer on designate position of DNA origami, wecan study the thrombin binding capacity effect by different buffers and differentconcentration metal ions (K ion) on a single molecular lever. It turns out that HEPESbuffer is better and when the K iron concentration is20mMol/L preferably. Theexperimental results will help us deepen the understanding of the relationship of thespecific recognition between aptamer and the target molecule. Hoping this experiment willmotivate more research in biomolecular recognition with the help of DNA origami.