Polyelectrolyte Multilayer Assemblies and Protein Immobilization A Study of Protein-Protein and Protein-Polyelectroyte Interactions

Date of Award

2005

Document Type

Thesis

Degree Name

Bachelors

Department

Natural Sciences

First Advisor

Johal, Malkait

Keywords

B-galactosidase, Protein-Protein Interactions, B-galactosidase

Area of Concentration

Chemistry

Abstract

The principal goal of this research is to explore the possibility of using polyelectrolyte films to study specific protein-protein interactions. To this end, electrostatic self-assembly (ESA) was applied to the immobilization of EA22, a-peptide, and full length B-galactosidase. Each of these proteins was immobilized onto polyelectrolyte precursor films consisting of 5 poly (ethylenimine) (PEI)/poly{l-[4-(3-carboxyl-4-hydroxyphenylazo) benzene sulfonamido]-1,2-ethanediyl, Na salt} (PAZO) bilayers. Based on their ability to spontaneously associate to form the biologically active enzyme, B-galactosidase, EA22 and a-peptide were chosen as a convenient model for specific protein-protein interactions. UV-visible spectroscopy, single wavelength Ellipsometry, and catalytic assays were performed to characterize the sequential adsorption of EA22 and a-peptide. The same methods were applied to the characterization of films with a terminal layer of immobilized �-galactosidase. The results presented in this thesis represent an important preliminary study towards achieving the principal goal. The data obtained from the films fabricated in this research demonstrate that the interactions of immobilized enzymes with underlying polyelectrolyte layers have significant effects on their catalytic activity. In the case of �-galactosidase the enzyme retained its catalytic activity when it was immobilized onto a terminal oppositely charged PEl layer. On the other hand the enzyme was inactive when it was in direct contact with a terminal like charged PAZO layer. This underscores the importance of choosing an appropriate model system for this kind of study. It should be noted that recombinant DNA techniques were used to obtain the a-peptide used in this research. The results from this portion of the research are also discussed.

Rights

This bibliographic record is available under the Creative Commons CC0 public domain dedication. The New College of Florida, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.

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