LAUSR

In this study, an accurately and digitally-regulated allosteric nanoswitch based on the conformational control of two DNA hairpins was developed. By switching between UV irradiation and blue light condition, the second molecular beacon (H#2) would bind/separate with a repression sequence (RES) via the introduced PTG molecules (a photosensitive azobenzene derivative), resulting in that the target aptamer sequence in the first molecular beacon (H#1) cannot/can hold the stem-loop configuration, hence, losing/regaining the ability to bind with the target. Importantly, we successfully monitor conformation changes of the nanoswitch by an elegant mathematical model for connecting K_i (the dissociation constant between RES and H#2) with Kd (the overall equilibrium constant of the nanoswitch binding the target), hence, realizing "observing" DNA structure across dimensions from "structural visualization" to digitization, and accurately, digitally regulating DNA structure from digitization to "structural visualization".