Access Type

Open Access Embargo

Date of Award

January 2020

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Physics and Astronomy

First Advisor

Christopher V. Kelly

Abstract

Nanoscale membrane curvature on cell plasma membrane assists in the spatial organization and domain formation that are critical for life of eukaryotic cells. Lipids and proteins can sense, be sorted by, and generate both functional domains and membrane curvature. Reveal the relationship between membrane curvature, phase separation, and single-molecule behavior is a key to understanding fundamental processes, such as phagocytosis initiation, cell signaling, and membrane budding. Single lipid dynamic and sorting on engineered membrane curvature is studied to understand the effects of fluorescence labeling, composition, phase separation, and temperature. Single particle tracking was used to find radial averaged diffusion at membrane curvature. Lipids with varying shapes and fluorophore labeling method were first to be examined. We conclude that the fluorophore labeling strategy on lipids effected the lipids diffusion, but non-fluorescent membrane composition had no significant effects when a single lipid phase was present. Membrane with ternary mixtures that have co-exist phases was then tested. Disorder phase preferring lipids sorts to curvature, even at disorder surrounded curvatures. Dynamic and sorting on phase-separated membrane were quantified. These studies will contribute to the greater biophysical understanding of membrane curvature, which could potentially improve the effectiveness of therapeutic design and pathogen protection.

Included in

Biophysics Commons

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