Publication Date

2017

Document Type

Dissertation/Thesis

First Advisor

Lurio, Laurence B.

Degree Name

Ph.D. (Doctor of Philosophy)

Department

Department of Physics

LCSH

Physics

Abstract

Study of structure and dynamic behavior is essential to understand molecular motions in biological systems. In this work, two biomaterials were studied to address membrane properties and protein diffusion. For the first project, we studied the structure of liposomes, artificial vesicles that are used for drug encapsulation and administration of pharmaceuticals or cellular nutrients. Small-angle x-ray scattering (SAXS) was used to determine the structural properties of different liposomes composed of egg-PC and cholesterol bilayer. We examined the location of cholesterol by labelling cholesterol with bromine molecule and reveal that cholesterol is located one side of the leaflet adjusting itself to the curvature of a liposome. In my second project, we studied the dynamics of concentrated suspensions of alpha crystallin, one of the most abundant proteins in the human eye lens using X-ray photon correlation spectroscopy (XPCS). An improved understanding of dynamics could point the way towards treatments presbyopia and cataract. The dynamics were measured at volume fraction close to the critical volume fraction for the glass transition, where the intermediate scattering function, f(q,T) could be well fit using a double exponential decay. The measured relaxation is in reasonable agreement with published molecular dynamics simulations for the relaxation times of hard-sphere colloids.

Comments

Advisors: Laurence B. Lurio.||Committee members: Elizabeth Gaillard; Carol Thompson.||Includes bibliographical references.||Includes illustrations.

Extent

viii, 63 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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