Condensed Matter and Materials Physics(DCMMP)
Physique de la matière condensée et des matériaux (DPMCM)
Bae-Yeun HA
University of Waterloo
Statics and dynamics of biopolymers: theory and biological relevance
In this talk, I will discuss conformational and dynamical properties of biomolecules with an emphasis on their biological implications. I will first present simple theoretical models for describing loop formation of DNA, both double-stranded (ds) and single-stranded (ss) DNA. In the case of dsDNA (or other semiflexible polymers), large loops are entropically disfavored, while small-loop formation costs bending energy. This results in an optimal loop size at which the closing time is shortest. In contrast, the looping kinetics of short ssDNA is mainly controlled by stacking-breakage probability and shows loop-composition sensitivity. Finally, I will discuss polyelectrolyte aspects of DNA, especially the electrostatic mechanism behind DNA packaging by polyvalent counterions.