Dynamic DNA Assembly by Programmable Hybridization Chain Reaction Mimicking Tubulin

Dynamic biological structures involve the continual turnover of molecules within supramolecular assemblies such as tubulin. Inspired by dynamic biology self-organizing systems, we build an artificial dynamic structure based on DNA nanotechnology through a nonequilibrium chemical system. Herein, a metastable domain (MD), essentially a stem-loop structure, was introduced into DNA hairpins within hybridization chain reaction (HCR), thereby imparting dynamic activity to the DNA polymers. Hairpins with MD thermodynamically assemble to a high-energy polymer in the presence of trigger strands. The polymer can relax back to the stable unassembled state once the invader is added and finally relax to the activated hairpin by an anti-invader. Reversible assembly/disassembly of the HCR is achieved through invader/anti-invader cycles. We accomplished kinetic modulation, reversible conformational switching, cascading regulation, and enzyme activity control through the MD-HCR. We believe that the design of the MD-HCR could inspire the development of autonomous biological functions within artificial systems.