Physical Sciences and Mathematics Commons^™

Citrate Binding To The Membrane Protein Proteorhodopsin, Farhana F. Syed

Chemistry - Dissertations

Proteorhodopsin (pR) is an intrinsic membrane protein with an important role in solar-energy storage of the biosphere. Earlier work in our lab has shown that polyhistidine-tagged pR can be purified by means of selective precipitation with citrate under specific conditions, as can a number of mutants based on this His₆-tagged pR. Purification of a heterologously-expressed trans-membrane protein by a simple salt such as citrate is novel. However, such a phenomenon leads to several questions: How does citrate cause pR precipitation? Does the polyhistidine-tag assist in such a precipitation? Is this precipitation pH-specific? Does citrate affect the function of …

Controlling Biofouling By Surface Engineering And Molecular Inhibition, Debjyoti Bandyopadhyay

Chemistry - Dissertations

The common theme that binds together all the chapters in this dissertation is anti-biofouling chemistry. By utilizing tools of surface engineering and molecular inhibition, a hypothesis driven, systematic approach of controlling the different forms of biofoulings such as protein adsorption, mammalian cell adhesion and biofilm formation is presented. Chapter 1 provides a brief introduction about topics relevant for understanding the studies presented in subsequent chapters. Chapter 2 reports the synthesis of enantiomerically pure alkanethiols that terminate with different stereoisomer's of sugar alcohols, and the effect of chirality of these polyol-terminated self-assembled monolayers (SAMs) on resisting protein adsorption.

Chapter 3 …

Synthesis And Biosynthesis Of Polyketide Natural Products, Atahualpa Pinto

Chemistry - Dissertations

Traditionally separate disciplines of a large and broad chemical spectrum, synthetic organic chemistry and biochemistry have found in the last two decades a fertile common ground in the area pertaining to the biosynthesis of natural products. Both disciplines remain indispensable in providing unique solutions on numerous questions populating the field. Our contributions to this interdisciplinary pursuit have been confined to the biosynthesis of polyketides, a therapeutically and structurally diverse class of natural products, where we employed both synthetic chemistry and biochemical techniques to validate complex metabolic processes. One such example pertained to the uncertainty surrounding the regiochemistry of dehydration and …

Mutational Analysis Of Hiv-1 Nucleocapsid Protein And Methods Development For Aptamer Discovery, Wei Ouyang

Chemistry - Dissertations

This dissertation focuses on structural and functional studies related to the interaction between proteins and nucleic acids and their applications. The work reported here includes two projects. The first part of the thesis is on the mutational and combinatorial analysis of HIV-1 nucleocapsid protein (NCp7). Sixteen mutants of NCp7 were constructed and over-expressed in E. coli . The dissociation constants (K _d ) between the mutant proteins and the major packaging signal in HIV-1, SL3 RNA, were measured using tryptophan fluorescence titration assay and/or isothermal titration calorimetry (ITC) assay. Most mutants show tolerance of the mutation but some mutants, including …