Metallomembranes: Characterizing Transition Metal Ion-Lipid Complexes

Open Access
Author:
Poyton, Matthew Forrest
Graduate Program:
Chemistry
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
December 02, 2015
Committee Members:
  • Paul S Cremer, Dissertation Advisor
  • Tom Mallouk, Committee Member
  • Ayusman Sen, Committee Member
  • Moses Hung Wai Chan, Committee Member
Keywords:
  • Lipid Bilayers
  • Microfluidics
  • Lipid Oxidation
  • Fluorescence Quenching
  • Supported Lipid Bilayer Electrophoresis
Abstract:
Herein, transition metal-lipid complexes are characterized using model membranes. We show that Cu2+, Zn2+ and Ni2+ bind to phosphatidylserine (PS) lipids and that Cu2+ also binds with the lipid phosphatidylethanolamine (PE). These transition metals can induce dramatic chemical or physical changes to the lipid membrane upon binding. For example, oxidation rates in the presence of Cu2+ and hydrogen peroxide were significantly higher for bilayers containing PE than for pure phosphatidylcholine (PC) bilayers that do not bind Cu2+. Zn2+ was found to induce membrane blebbing upon binding to supported bilayers containing PS lipids. A second objective of this work was to develop new analytical tools for studying transition metal-lipid complexes. We propose that the family of transition metal-lipid complexes be referred to as metallomembranes. These results suggest that metallomembrans are physiologically relevant and may play a role in diseases where the Cu2+ concentration in the body is abnormally high.