Date of Award
2-5-2025
Publication Type
Thesis
Degree Name
M.Sc.
Department
Chemistry and Biochemistry
Keywords
DMPC; Lipids; Membranes; Neutrons; small angle neutron scattering; Vitamin E
Supervisor
Drew Marquardt
Rights
info:eu-repo/semantics/openAccess
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Abstract
Biological membranes are a defining component of cellular life. These structures, mainly composed of proteins dispersed in a lipid bilayer, separate cells from the external world, compartmentalize organelles and enable various biological processes. Although these membranes appear to have a rather simple construction, upon closer inspection they possess a diverse array of constituent molecules in constant flux. At the heart of this diversity are the lipids, which not only have countless structural forms but a unique spatial and temporal distribution. With this in mind, we employ small angle neutron scattering, to explore the equilibrium bilayer asymmetry and dynamics of lipids in synthetic biomimetic model membranes. The use of this probe-free technique enables us to study lipids in a native, un-perturbed state and apply this information to enhance our understanding of the distribution and movement of lipids in a biological context. This thesis is divided into four chapters: The first chapter serves as an introduction to biomembrane research. It provides a historical review of the cell membrane and more recent scientific developments in the field. Additionally, the use of synthetic liposomes as biological membrane mimics and various biophysical techniques used to study membrane structure and dynamics are discussed. The second chapter examines the transverse asymmetric bilayer organization of lipids in biomimetic liposomes. Often assumed to form symmetric bilayers under equilibrium conditions, small angle neutron scattering, a custom data fitting model and a specialized contrast match scheme are used to show that this is not always the case. Chapter three uses time-resolved small angle neutron scattering to study vitamin E's dynamics in saturated model membranes. The rates of intervesicular exchange (kex) and intrabilayer flip-flop (kf) are assessed in a few conditions, such as different liposome concentrations and the presence of various cyclodextrins. These results provide potential insights into vitamin E's antioxidative role within membranes. Chapter four serves to conclude the work presented herein. It explains how these results enhance our current knowledge of biomembranes and outlines future work that can be performed to extend our understanding of lipid organization and dynamics.
Recommended Citation
Dziura, Dominik, "Elucidating the Dynamics and Equilibrium Asymmetric Organization of Lipids in Biomimetic Model Membranes" (2025). Electronic Theses and Dissertations. 9653.
https://scholar.uwindsor.ca/etd/9653