ABSTRACT
Polymers exhibit unique physical properties due to chain-like structures, and accordingly have been adopted by natural evolution to build biomolecules, e.g. DNA and proteins, as well as utilized by human for modern materials, e.g. rubber. Developing simple physics theories for the unique physical behaviors caused by the chain-structure of biopolymers and applying these results in biology and technology are my major research theme. In this talk, I will present my recent results about knotted and confined DNA. We developed a simple theory to calculate the probability and size of random DNA knots, which were validated by recent DNA nanopore experiments. We also refined the classic blob theory for DNA in confinement, which was developed by de Gennes, a Nobel Laureate. The predictions of our refined theory were validated by our computer simulations and others’ experiments. Our results not only developed physics theories for biopolymers but also have biological implications, e.g. DNA packaging and protein folding in vivo, as well as technological applications, e.g. DNA sequencing.
BIOGRAPHY
Dr. Liang Dai is currently a research scientist in the BioSystems and Micromechanics Inter-Disciplinary Research Group of Singapore-MIT Alliance for Research and Technology (SMART). Dr. Dai pursued his undergraduate study from 2000 to 2004 in the physics department of the University of Science and Technology of China (USTC), followed by a PhD study from 2004 to 2009 in the physics department of National University of Singapore (NUS). Before joining SMART in 2010, Dr. Dai was a postdoctoral researcher in the Center for Computational Biology and Bioinformatics of Indiana University. Dr. Dai applies multi-scale (from atomistic to coarse-grained) modeling and statistical mechanics to conduct research in soft matter physics and biophysics, with tight collaboration with experimental groups in MIT and NUS.