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

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.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Physics

Department dc:contributor.department

Physics

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2019

Author dc:creator

• Charkhesht, Ali

Chair dc:contributor.committeechair

• Nguyen, Vinh

Committee members dc:contributor.committeemember

• Khodaparast, Giti
• Pleimling, Michel J.
• Robinson, Hans

• Terahertz Spectroscopy
• Dielectric Spectroscopy
• Molecular Dynamics
• Hydration Dynamics
• Proteins

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

vt_gsexam:20653

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/101513