Probing Collective Motions and Hydration Dynamics of Biomolecules by a Wide Range Dielectric Spectroscopy

Charkhesht, Ali

Probing Collective Motions and Hydration Dynamics of Biomolecules by a Wide Range Dielectric Spectroscopy

dc.contributor.author	Charkhesht, Ali	en
dc.contributor.committeechair	Nguyen, Vinh	en
dc.contributor.committeemember	Khodaparast, Giti	en
dc.contributor.committeemember	Pleimling, Michel J.	en
dc.contributor.committeemember	Robinson, Hans	en
dc.contributor.department	Physics	en
dc.date.accessioned	2020-12-17T07:00:25Z	en
dc.date.available	2020-12-17T07:00:25Z	en
dc.date.issued	2019-06-25	en
dc.description.abstract	Studying dynamics of proteins in their biological milieu such as water is interesting because of their strong absorption in the terahertz range that contain information on their global and sub-global collective vibrational modes (conformational dynamics) and global dynamical correlations among solvent water molecules and proteins. In addition, water molecules dynamics within protein solvation layers play a major role in enzyme activity. However, due to the strong absorption of water in the gigahertz-to-terahertz frequencies, it is challenging to study the properties of the solvent dynamics as well as the conformational changes of protein in water. In response, we have developed a highly sensitive megahertz-to-terahertz dielectric spectroscopy system to probe the hydration shells as well as large-scale dynamics of these biomolecules. Thereby, we have deduced the conformation flexibility of proteins and compare the hydration dynamics around proteins to understand the effects of surface-mediated solvent dynamics, relationships among different measures of interfacial solvent dynamics, and protein-mediated solvent dynamics based on the complex dielectric response from 50 MHz up to 2 THz by using the system we developed. Comparing these assets of various proteins in different classes helps us shed light on the macromolecular dynamics in a biologically relevant water environment.	en
dc.description.abstractgeneral	Proteins are complicated biomolecules that exist in all living creatures and they are, mostly, involved in building up structures and cell functions in various biological systems. Not only their existence but also their complex movements and dynamics are vital to cell functions in living beings. Until recently, their chemical functions and dynamics have been extremely challenging to investigate and track in their native environments. Thanks to various efforts by researchers all over the world to learn more about their convoluted behavior, new techniques have arisen to study these properties. We, as a part of this community, have been able to develop highly sensitive megahertz-to-terahertz dielectric spectroscopy system to probe proteins and other biomolecules dynamics in picosecond to microsecond range. Using our benchmark system, we have been able to map the detailed dynamical properties of biomolecules as well as their exclusive hydration shell characterizations. In this work, we gathered details about three well-known proteins and biomolecules by studying their dielectric responses. Thus, we have been able to discuss the movements, relaxation processes and hydration shell properties of these molecules in liquid water as their basic native environment.	en
dc.description.degree	Doctor of Philosophy	en
dc.format.medium	ETD	en
dc.identifier.other	vt_gsexam:20653	en
dc.identifier.uri	http://hdl.handle.net/10919/101513	en
dc.publisher	Virginia Tech	en
dc.rights	In Copyright	en
dc.rights.uri	http://rightsstatements.org/vocab/InC/1.0/	en
dc.subject	Terahertz Spectroscopy	en
dc.subject	Dielectric Spectroscopy	en
dc.subject	Molecular Dynamics	en
dc.subject	Hydration Dynamics	en
dc.subject	Proteins	en
dc.title	Probing Collective Motions and Hydration Dynamics of Biomolecules by a Wide Range Dielectric Spectroscopy	en
dc.type	Dissertation	en
thesis.degree.discipline	Physics	en
thesis.degree.grantor	Virginia Polytechnic Institute and State University	en
thesis.degree.level	doctoral	en
thesis.degree.name	Doctor of Philosophy	en