Dynamics of Biopolymers: Role of Hydration and Electrostatic Interactions

Abstract

This contribution highlights the recently developed microscopic picture of the effects of hydration and electrostatic interactions on subnanosecond dynamics of biopolymers protein and ribonucleic acid (RNAstudied by quasielastic neutron scattering spectroscopy. In contrast to the traditional concept of water-slaved dynamics, more detailed analysis of the dynamics of different chemical structures (lysozyme vs transfer RNA; electrostatically unscreened vs screenedemonstrates that chemical and physical responses of biopolymers to hydration and charge screening determine the dynamic interactions. How the relationship of the dynamical flexibility and structural stability varies depending on water-driven or charge screening-driven folding into biologically active structures has also been discussed. However, the biological relevance of the fast conformational dynamics still remains elusive. Exploring the dynamic heterogeneity of biopolymers is proposed as a potential approach to the identification of biologically important dynamics. Water serves as the integral medium of biologically relevant dynamics of biopolymers. It is found that water-coupled dynamics of protein and RNA vary with thermodynamic balance between dynamical flexibility and structural stability determined in the chemical and physical responses of biopolymers to hydration and charge screening. This provides insight into the general concept of biologically important dynamics which remain elusive. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim