Active DNA Olympic Hydrogels Driven by Topoisomerase Activity

Brad A. Krajina, Audrey Zhu, Sarah C. Heilshorn, and Andrew J. Spakowitz

Phys. Rev. Lett. 121, 148001 – Published 1 October 2018

Abstract

Biological systems are equipped with a diverse repertoire of proteins that regulate DNA topology with precision that is beyond the reach of conventional polymer chemistry. Here, we harness the unique properties of topoisomerases to synthesize Olympic hydrogels formed by topologically interlinked DNA rings. Using dynamic light scattering microrheology to probe the viscoelasticity of DNA topological networks, we show that topoisomerase II enables the facile preparation of active, adenosine triphosphate–driven Olympic hydrogels that can be switched between liquid and solid states on demand. Our results provide a versatile system for engineering switchable topological materials that may be broadly leveraged to model the impact of topological constraints and active dynamics in the physics of chromosomes and other polymeric materials.

Received 18 April 2018
Revised 7 August 2018

DOI:https://doi.org/10.1103/PhysRevLett.121.148001

Physics Subject Headings (PhySH)

Polymer conformation & topology Viscoelasticity

Active gels DNA Motor proteins

Microrheology

Polymers & Soft Matter

Authors & Affiliations

Brad A. Krajina¹, Audrey Zhu¹, Sarah C. Heilshorn², and Andrew J. Spakowitz^1,2,3

¹Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA
²Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
³Department of Applied Physics, Stanford University, Stanford, California 94305, USA