Entropic barrier of topologically immobilized DNA in hydrogels
Abstract
Movement of charged macromolecules in crowded aqueous environments is ubiquitous in nature. The omnipresent capacity of macromolecules to adopt differing numbers of conformations in response to local spatiotemporal environments results in their trajectories consisting of conformational entropic barriers. The conformational fluctuations can be so large that even Einstein’s law of diffusion can apparently break down. By directly observing single DNA molecules under such conditions, we show the emergence of a nondiffusive topologically frustrated dynamical state, and measure single-molecule entropic barriers responsible for the resultant extreme metastability. The presented theory–experiment combination offers a general method to measure free energy landscapes required to deliberately navigate single macromolecules through congested aqueous media.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 06, 2021
- Source ID
- 10.1073/pnas.2106380118
Entities
People
- Kuo Chen
- Murugappan Muthukumar
Organizations
- Air Force Office of Scientific Research
- Division of Materials Research
- National Human Genome Research Institute
- University of Massachusetts