Date of Award

2000

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

First Advisor

Paul Russo

Abstract

This research was part of a multidisciplinary effort aimed at the elucidation of the mechanism of membrane lysis by model peptides. The focus of the dissertation was to characterize the average size dimensions of model cell membranes before and after being treated by model peptides. Experiments with neutral dioleoylphosphatidylcholine (DOPC) vesicles and negatively charged dioleoylphosphabdylcholine/dioleoylphosphabdylglycerol (DOPC/DOPG) vesicles were conducted using the model peptides (KLAKKLA) 3 and (KLGKKLG)3. A melittin study was conducted alongside for comparison. Changes in membrane integrity were studied as a function of lipid-to-peptide (L:P) ratio using three techniques: kinetic light scattering (KLS), dynamic light scattering (DLS), and fluorescence photobleaching and recovery (FPR). The document is divided into four chapters. The first chapter gives a general introduction. The second chapter introduces the KLS concept along with latex calibrations and preliminary measurements of surfactant/vesicle interactions. In chapter 3 the interaction between neutral and negatively charged vesicles composed of dioleoylphosphatidylcholine (DOPC) and dioleoylphosphatidylglycerol with the model peptides (KLAKKLA)3 and (KLGKKLG)3 is examined as a function of lipid-to-peptide ratio. Chapter 4 outlines a complement FPR study to chapter 3. Also presented in this chapter are results from experiments of the same lipid systems with melittin.

ISBN

9780599682252

Pages

98

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