MANIPULATING AND MEASURING THE PHYSICAL
PROPERTIES AND LOCAL STRUCTURE OF BIOMEMBRANES
Open Access
Author:
D'Onofrio, Terrence
Graduate Program:
Chemistry
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
March 12, 2003
Committee Members:
William O Hancock, Committee Member David Lawrence Allara, Committee Member Erin Elizabeth Sheets, Committee Member Paul S Weiss, Committee Chair/Co-Chair
Local composition, structure, morphology, and phase are interrelated in lipid bilayer
membranes. This gives us the opportunity to control one or more of these properties by
manipulating others. These properties are important in biology for endocytosis and
exocytosis, lipid raft formation, and lateral diffusion of membrane-bound species.
We discuss methods of preparing two-component/two-phase giant unilamellar vesicles as
models for biological membranes and we detail the development of tools to measure and
to control the properties of these membranes. We investigate these relationships with
combinations of simultaneous two-color widefield fluorescence imaging, threedimensional
rendering of vesicle domains, and manipulation of the vesicle morphology
and measurement of the material properties via micropipette aspiration. We demonstrate
microtubule degradation induced by free radicals that penetrate the membrane. Such
systematic measurements are critical in understanding the roles of individual membrane
components and their aggregate effects on the behavior of the whole system.
