Chemistry Commons^™

Synthesis, Characterization, And Application Of High Surface Area, Mesoporous, Stabilized Anatase Tio2 Catalyst Supports, Rebecca Elizabeth Olsen

Theses and Dissertations

Nanomaterials have attracted substantial attention in the area of catalysis due to the unique properties they exhibit such as high surface areas, intricate pore networks and unique morphologies. TiO2 has attracted attention as a catalyst since the discovery of its high photocatalytic activity by Fuishima and Honda in 1972. Given its high thermal stability, low cost, low environmental impact, and versatility, TiO2 is a widely used commercial catalyst and catalyst support. TiO2 is used in many applications such as photocatalysis is also an excellent support material for noble metals in a number of oxidative synthesis and pollution-control reactions. Though TiO2 …

Nonlinear Spectroscopic Investigation Of Adsorption To C-18 Model Stationary Phase, Anthony D. Peterson

Theses and Dissertations

Reversed-phase liquid chromatography (RPLC) is a commonly used separation technique in chemistry. Nevertheless, the mechanistic interactions at the molecular level among the eluent, analyte, and the stationary phase are not fully understood. Because of this limited understanding, optimization of the separation must be done experimentally. Learning more about molecular interactions should aid in improving separations. We are currently using second-harmonic generation (SHG) spectroscopy to investigate how analytes adsorb to the surface. SHG is a spectroscopic technique that produces signal only at places of non-isotropic symmetry; this typically occurs at surfaces. SHG can be used to produce surface isotherms of test …

Formation And Analysis Of Zinc Oxide Nanoparticles And Zinc Oxide Hexagonal Prisms And Optical Analysis Of Cadmium Selenide Nanoparticles, Jared M. Hancock

Theses and Dissertations

In this dissertation, methods to synthesize ZnO are reported. First, zinc oxide nanoparticles were synthesized with small amounts of transition metal ions to create materials called dilute magnetic semiconductors (DMS). We employed a low temperature sol-gel method that produces ZnO nanoparticles of reproducible size and incorporates cobalt, nickel, and manganese ions into the nanoparticles. Conditions were controlled such that a range of amounts of Co, Ni, and Mn were incorporated. The incorporation was tracked by color changes in the white ZnO powder to blue for Co, green for Ni and yellow for Mn. XRD measurements showed the nanoparticles were on …

Identification Of Disulfide Bond Formation Between Mitoneet And Glutamate Dehydrogenase 1, Morgan E. Roberts, Jacquelyn P. Crail, Megan M. Laffoon, William G. Fernandez, Michael A. Menze, Mary E. Konkle

Faculty Research & Creative Activity

MitoNEET is a protein that was identified as a drug target for diabetes, but its cellular function as well as its role in diabetes remains elusive. Protein pull-down experiments identified glutamate dehydrogenase 1 (GDH1) as a potential binding partner. GDH1 is a key metabolic enzyme with emerging roles in insulin regulation. MitoNEET forms a covalent complex with GDH1 through disulfide bond formation and acts as an activator. Proteomic analysis identified the specific cysteine residues that participate in the disulfide bond. This is the first report that effectively links mitoNEET to activation of the insulin regulator GDH1.

Identification Of Disufide Bond Formation Between Mitoneet And Glutamate Dehydrogenase 1, Morgan E. Roberts, Jacquelyn P. Crail, Megan M. Laffoon, William G. Fernandez, Michael A. Menze, Mary E. Konkle

Faculty Research & Creative Activity

MitoNEET is a protein that was identified as a drug target for diabetes, but its cellular function as well as its role in diabetes remains elusive. Protein pull-down experiments identified glutamate dehydrogenase 1 (GDH1) as a potential binding partner. GDH1 is a key metabolic enzyme with emerging roles in insulin regulation. MitoNEET forms a covalent complex with GDH1 through disulfide bond formation and acts as an activator. Proteomic analysis identified the specific cysteine residues that participate in the disulfide bond. This is the first report that effectively links mitoNEET to activation of the insulin regulator GDH1.

Ferritin-Based Photo-Oxidation Of Biomass For Nanoparticle Synthesis, Bioremediation, And Hydrogen Evolution, Oscar Petrucci

Theses and Dissertations

The cell is the basic unit of all living organisms. It is an amazing machine capable of self-replicating, growing, and synthesizing and shuttling thousands of compounds. To perform all of these activities the cell needs energy. The original source of energy for all living beings is the Sun. The energy of the sun is collected by the autotrophs (mostly plants) through photosynthesis and stored in the chemical bonds of carbohydrates and lipids through carboxylic acid intermediates; animals use these compounds to obtain the energy for their cells. Most of the energy extracted by the cell comes from the citric acid …

Monodentate, Bidentate And Photocrosslinkable Thiol Ligands For Improving Aqueous Biocompatible Quantum Dots, Hiroko Takeuchi

Graduate Theses and Dissertations

Water-soluble Quantum Dots (QDs) are highly sensitive fluorescent probes that are often used to study biological species. One of the most common ways to render QDs water-soluble for such applications is to apply hydrophilic thiolated ligands to the QD surface. However, these ligands are labile and can be easily exchanged on the QD surface, which can severely limit their application. As one way to overcome this limitation while maintaining a small colloidal size of QDs, we developed a method to stabilize hydrophilic thiolated ligands on the surface of QDs through the formation of a crosslinked shell using a photocrosslinking approach. …

The Development And Applications Of Nmr Metabolomics Analysis Of Bacterial Metabolomes, Steven M. Halouska

Department of Chemistry: Dissertations, Theses, and Student Research

Metabolomics is a relatively new field that involves the study of metabolic responses that are occurring within a biological system. Metabolite profiles of an organism, tissue extract, and biofluids are important indicators to determine the physiological state of a biological profile. Comparison of such profiles from different phenotypes can be used to identify specific metabolic changes leading to the understanding of metabolic pathways, disease progression, drug toxicity and efficacy, and cellular responses to different intracellular and extracellular conditions. Metabolomics investigations often use sophisticated analytical techniques such as NMR spectroscopy to provide an unbiased and comprehensive approach to evaluate metabolic perturbation …

Obstacles And Solutions To Studying Functional Adhesives Using Vibrational Sum-Frequency Generation Spectroscopy, Angela Renee Andersen

Theses and Dissertations

Important aspects of adhesion occur at interfaces, including structures that may be different from those in the bulk materials. However, probing the orientation of molecules in functional adhesives poses a significant challenge because adhesive molecules are always located at a buried interface. The limited penetration depth of surface-specific analysis prohibits the study of buried interfaces using those techniques. The large quantity of bulk molecules relative to the adhesive molecules interacting at the interface results in the bulk signal swamping out adhesive signal in bulk analysis techniques. An interface-specific technique is required to study functional adhesives. One such technique that has …

Investigation Into The Effects Of Pegylation On The Thermodynamic Stability Of The Ww Domain, Sam S. Matthews

Theses and Dissertations

The covalent attachment of poly(ethylene glycol) (PEG) to a protein surface (known as PEGylation), has been demonstrated to increase the serum half-life of therapeutic proteins by reducing kidney clearance and immunogenicity and by protecting against proteolysis. Theses beneficial effects could be further enhanced if PEGylation consistently increased protein conformational stability (i.e. the difference in free energy between the folded and unfolded states). However, the effects of PEGylation on protein conformational stability are unpredictable; PEGylation has been reported to increase, decrease, or have no effect on the conformational stability of medicinal proteins.This thesis details the results of two studies aimed at …

Identification Of Disufide Bond Formation Between Mitoneet And Glutamate Dehydrogenase 1., Morgan Roberts, Jacquelyn Crail, Megan Laffoon, William Fernandez, Michael Menze, Mary Konkle

Faculty and Staff Scholarship

MitoNEET is a protein that was identified as a drug target for diabetes, but its cellular function as well as its role in diabetes remains elusive. Protein pull-down experiments identified glutamate dehydrogenase 1 (GDH1) as a potential binding partner. GDH1 is a key metabolic enzyme with emerging roles in insulin regulation. MitoNEET forms a covalent complex with GDH1 through disulfide bond formation and acts as an activator. Proteomic analysis identified the specific cysteine residues that participate in the disulfide bond. This is the first report that effectively links mitoNEET to activation of the insulin regulator GDH1.

Development Of A Biosensor For Investigating Membrane Curvature Sorting, Joshua C. Black

Electronic Theses and Dissertations

The physical structure of cellular membranes plays a critical role in lipid and protein sorting. A novel biosensor was developed to probe the influence of curvature on sorting. This biosensor mimics large, two-dimensional membranes in dynamic equilibrium, achieves high spatial resolution between curvature and molecules of interest, and has high sensitivity, enough for single particle detection. The biosensor consists of continuous supported lipid bilayer formed over nanoparticles (40 to 200 nm diameter) deposited on a glass substrate. The nanoparticles determine the extent of curvature. This biosensor is the first to observe large-scale 2-dimensional diffusion of biomolecules on a supported lipid …

Cytochrome P450 Family 1 Inhibitors And Structure-Activity Relationships, Jiawang Liu, Jayalakshmi Sridhar, Maryam Foroozesh

Faculty and Staff Publications

With the widespread use of O-alkoxyresorufin dealkylation assays since the 1990s, thousands of inhibitors of cytochrome P450 family 1 enzymes (P450s 1A1, 1A2, and 1B1) have been identified and studied. Generally, planar polycyclic molecules such as polycyclic aromatic hydrocarbons, stilbenoids, and flavonoids are considered to potentially be effective inhibitors of these enzymes, however, the details of the structure-activity relationships and selectivity of these inhibitors are still ambiguous. In this review, we thoroughly discuss the selectivity of many representative P450 family 1 inhibitors reported in the past 20 years through a meta-analysis.

Influence Of Cholesterol And Bilayer Asymmetry On Membrane Protein Distribution In Polymer-Tethered Raft-Mimicking Lipid Membranes, Noor Fueza Hussain

Open Access Dissertations

It is now widely recognized that lipid rafts, which are membrane domains enriched in cholesterol (CHOL) and sphingolipids (SL), play a significant functional role in the plasma membrane. Raft domains particularly affect membrane functionality by causing sequestering of membrane proteins. Underlying mechanisms of raft-associated membrane protein sequestration remain elusive, due to the complexity, transient nature, and small size of raft domains in cellular membranes. To address these challenges, this dissertation unveils the relationship between lipid raft composition and membrane protein sequestration and function using raft-mimicking model membrane mixtures comprised of coexisting liquid-ordered (lo) and liquid-disordered (ld) domains with reconstituted membrane …

Development Of Isotags For Nmr Based Metabolite Profiling And Applications, Fariba Tayyari

Open Access Dissertations

NMR spectroscopy is a powerful analytical tool for both qualitative and quantitative metabolite profiling analysis. However, accurate quantitative analysis of biological systems especially using one dimensional NMR has been challenging due to signal overlap. In contrast, the enhanced resolution and sensitivity offered by chemoselective isotope tags have enabled new and enhanced methods for detecting hundreds of quantifiable metabolites in biofluids using NMR spectroscopy or mass spectrometry. In this thesis we show improved sensitivity and resolution of NMR experiments imparted by 15N and 13C isotope tagging which enables the accurate analysis of plasma metabolites. To date, isotope tagging has been used …

Gas-Phase Covalent And Non-Covalent Ion/Ion Chemistry Of Biological Macromolecules, John Robert Stutzman

Open Access Dissertations

Gas-phase ion/ion chemistry involves the interaction of oppositely charged ions inside of the mass spectrometer. During this gas-phase chemistry, particle transfer (i.e., proton and electron) or synthesis can occur at rapid reaction rates. Particle transfer represents a mature area of ion/ion chemistry, while selective covalent modification represents a fairly new area of gas-phase chemistry. Gas-phase covalent chemistry is based on traditional solution phase organic chemistry.

The work demonstrated in this dissertation greatly involves gas-phase covalent and non-covalent Schiff base chemistry on peptide and protein ions. The reagent dianion, 4-formyl 1,3-benzene disulfonic acid, has been used to covalently modify unprotonated primary …

Design, Synthesis, And Evaluation Of Molecular Inhibitors For Biologically Relevant Enzymes, Sarah Emma St. John

Open Access Dissertations

The work in this thesis details the design, synthesis, and biological evaluation of molecular inhibitors for the inhibition of biologically relevant enzymes. The first three chapters of this thesis concern the polyphenol resveratrol and its inhibition of the quinone reductase 2 (QR2) enzyme. The work on this subject resulted in the complete design, synthesis, biological and structural evaluation of a second generation library of resveratrol analogues. From this work we identified a novel resveratrol analogue that inhibits QR2 in a previously unknown binding orientation. The fourth chapter of this thesis details the de novo design of molecules for the inhibition …

Synthesis Of Novel Isoprenoid Diphosphate Analogs As Chemical Tools To Investigate Protein Geranylgeranylation, Kayla Jo Temple

Open Access Dissertations

Many proteins require prenylation in order to be biologically functional. Some such proteins include the small Ras and Rho GTPase superfamilies, nuclear lamins A and B, and the kinesin motor proteins CENP-E and F. Prenyltransferase (PTase) inhibition is currently being explored as a possible treatment not only for cancer but for a wide variety of other diseases.

Clinical studies revealed that the effectiveness of farnesyltransferase inhibitors (FTIs) to treat Ras-dependent tumors is determined by which isoform of Ras is overactive. Unfortunately the majority of Ras-dependent tumors have a mutation in either the N- or K-Ras isoforms; both of these isoforms …

Size-Based Separation Of Bioparticles Using Planar Nanofluidic Devices, Jie Xuan

Theses and Dissertations

Nanofluidic devices are structures having at least one dimension in the submicron range, which is of the same order of magnitude as the sizes of biomolecules and bioparticles such as proteins and viruses. As a result, size-selective separations are important applications for nanofluidics. Well-defined micro or nano device structures fabricated via micromachining have greatly reduced sample consumption and enabled separations in a parallel fashion, promising significant speed and resolution advantages over conventional size separation techniques, such as gel electrophoresis and size exclusion chromatography. In collaboration with others, I have developed a size separation method using nanofluidic devices consisting of an …

Formation, Functionalization, Characterization, And Applications Of A Mixed-Mode, Carbon/Diamond-Based, Core-Shell Phase For High Performance Liquid Chromatography, Landon A. Wiest

Theses and Dissertations

My work has focused on a variety of different types of diamond-based, core-shell particles. These particles are formed with inert cores and poly(allylamine)/nanodiamond shells. Their intended purpose is to form an LC stationary phase that is stable from pH 1 – 14 and at elevated temperatures. At the beginning of my studies, the particles that had been made in the Linford laboratory were pH stable, but irregular and had poor mechanical stability. Since that time, I have worked to improve the particles by using more spherical zirconia and carbon cores, and I have improved their mechanical stability via chemical crosslinking …

Membrane Lipid-Modulated Mechanism Of Action And Non-Cytotoxicity Of Novel Fungicide Aminoglycoside Fg08, Sanjib Shrestha, Michelle Grilley, Marina Y. Fosso, Cheng-Wei Tom Chang, Jon Y. Takemoto

Chemistry and Biochemistry Faculty Publications

A novel aminoglycoside, FG08, that differs from kanamycin B only by a C8 alkyl chain at the 4″-O position, was previously reported. Unlike kanamycin B, FG08 shows broad-spectrum fungicidal but not anti-bacterial activities. To understand its specificity for fungi, the mechanism of action of FG08 was studied using intact cells of the yeast Saccharomyces cerevisiae and small unilamellar membrane vesicles. With exposure to FG08 (30 µg mL−1), 8-fold more cells were stained with fluorescein isothiocyanate, cells had 4 to 6-fold higher K+ efflux rates, and 18-fold more cells were stained with SYTOX Green in comparison to exposure to kanamycin B …

Laboratory Characterization Of Pm Emissions From Combustion Of Wildland Biomass Fuels, S. Hosseini, S. P. Urbanski, P. Dixit, L. Qi, I. R. Burling, Robert J. Yokelson, T. J. Johnson, M. Shrivastava, H. S. Jung, D. R. Weise, J. W. Miller, D. R. Cocker Iii

Chemistry and Biochemistry Faculty Publications

[1] Particle emissions from open burning of southwestern (SW) and southeastern (SE) U.S. fuel types during 77 controlled laboratory burns are presented. The fuels include SW vegetation types: ceanothus, chamise/scrub oak, coastal sage scrub, California sagebrush, manzanita, maritime chaparral, masticated mesquite, oak savanna, and oak woodland, as well as SE vegetation types: 1 year, 2 year rough, pocosin, chipped understory, understory hardwood, and pine litter. The SW fuels burned at higher modified combustion efficiency (MCE) than the SE fuels resulting in lower particulate matter mass emission factor. Particle mass distributions for six fuels and particle number emission for all fuels …

Protein Similarity Networks Reveal Relationships Among Sequence, Structure, And Function Within The Cupin Superfamily, Richard Uberto, Ellen W. Moomaw

Faculty Articles

The cupin superfamily is extremely diverse and includes catalytically inactive seed storage proteins, sugar-binding metal-independent epimerases, and metal-dependent enzymes possessing dioxygenase, decarboxylase, and other activities. Although numerous proteins of this superfamily have been structurally characterized, the functions of many of them have not been experimentally determined. We report the first use of protein similarity networks (PSNs) to visualize trends of sequence and structure in order to make functional inferences in this remarkably diverse superfamily. PSNs provide a way to visualize relatedness of structure and sequence among a given set of proteins. Structure- and sequence-based clustering of cupin members reflects functional …

Self-Assembled Dna Origami Templates For The Fabrication Of Electronic Nanostructures, Elisabeth Pound Gates

Theses and Dissertations

An important goal of nanoscience is the self-assembly of nanoscale building blocks into complex nanostructures. DNA is an important and versatile building block for nanostructures because of its small size, predictable base pairing, and numerous sequence possibilities. I use DNA origami to design and fold DNA into predesigned shapes, to assemble thin, branched DNA nanostructures as templates for nanoscale metal features. Using a PCR-based scaffold strand generation procedure, several wire-like nanostructures with varying scaffold lengths were assembled. In addition, more complex prototype circuit element structures were designed and assembled, demonstrating the utility of this technique in creating complex templates. My …

Shared Mycobacterium Avium Genotypes Observed Among Unlinked Clinical And Environmental Isolates, M. Ashworth Dirac, Kris M. Weigel, Mitchell A. Yakrus, Annie L. Becker, Hui-Ling Chen, Gina Fridley, Arthur Sikora, Cate Speake, Elizabeth D. Hilborn, Stacy Pfaller, Gerard A. Cangelosi

Chemistry and Physics Faculty Articles

Our understanding of the sources of Mycobacterium avium infection is partially based on genotypic matching of pathogen isolates from cases and environmental sources. These approaches assume that genotypic identity is rare in isolates from unlinked cases or sources. To test this assumption, a high-resolution PCR-based genotyping approach, large-sequence polymorphism (LSP)-mycobacterial interspersed repetitive unit–variable-number tandem repeat (MIRU-VNTR), was selected and used to analyze clinical and environmental isolates of M. avium from geographically diverse sources. Among 127 clinical isolates from seven locations in North America, South America, and Europe, 42 genotypes were observed. Among 12 of these genotypes, matches were seen in …

Computational Study Of The Cyclization Of 5-Hexenyl, 3-Oxa-5-Hexenyl And 4-Oxa-5-Hexenyl Radicals, Albert Matlin, Matthew C. Leyden

Faculty & Staff Scholarship

The intramolecular cyclization of 5-hexenyl radicals continues to be an important synthetic method for the construction of five-membered rings. The synthetic utility arises from the high degree of regioselectivity to give predominantly cyclopentyl products in high yield under mild conditions. Recently we reported product cyclization studies on 4-oxa perturbed 5-hexenyl radical. In this paper we report our results from a computational study (UB3LYP and UCCSD(T)) of the cyclization of a series of 5-hexenyl and 3- and 4-oxa-5-hexenyl radicals. Three highly conserved cyclization transitions states (exo-chair, exo-boat and endo-chair) were located for 10 acyclic radicals. Activation en-ergies …

Pitfalls With The Use Of Enhancement Ratios Or Normalized Excess Mixing Ratios Measured In Plumes To Characterize Pollution Sources And Aging, Robert J. Yokelson, Meinrat O. Andreae, S. K. Akagi

Chemistry and Biochemistry Faculty Publications

Normalized excess mixing ratios (NEMRs), also known as enhancement ratios, are a common way to characterize plumes of pollution in atmospheric research. As single-source pollutant plumes disperse in the atmosphere, they are diluted by mixing with the adjacent background air. Changes in the composition of this background air can cause large changes to the NEMR that is subsequently measured by remote-sensing, airborne, or ground-based instruments. This scenario is common when boundary layer plumes enter the free troposphere and could also impact long-range transport or plumes near the top of the troposphere. We provide a context for these issues and an …

A Supramolecular Strategy To Assemble Multifunctional Viral Nanoparticles, Limin Chen, Xia Zhao, Yuan Lin, Yubin Huang, Qian Wang

Faculty Publications

Using a one-pot approach driven by the supramolecular interaction between β-cyclodextrin and adamantyl moieties, multifunctional viral nanoparticles can be facilely formulated for biomedical applications.

Synthesis And Evaluation Of Thermally-Responsive Coatings Based Upon Diels–Alder Chemistry And Renewable Materials, Dahlia N. Amato, Gregory A. Strange, John P. Swanson, Anton D. Chavez, Suzanne E. Roy, Kim L. Varney, Craig A. Machado, Douglas V. Amato, Philip Costanzo

Chemistry and Biochemistry

A soybean based coating with thermally responsive Diels–Alder linkages has been prepared following an automotive 2-component formulation. The resulting coatings displayed the capability to be healed following physical deformation by a thermal stimulus, and such a material has significant potential for end users. Various curing agents were employed, and resulted in variation of scratch resistance and re-healablity. Different thermally responsive soybean resins were synthesized to have varying amounts reversible and nonreversible linkages when incorporated into the coating. Additionally, different isocyanates were added at differing ratios of NCO:OH in search of the optimum coating. It was found through the analysis of …

Mechanism Of Ubiquitin Ligation And Lysine Prioritization By A Hect E3, Hari B. Kamadurai, Yu Qiu, Alan Deng, Joseph S. Harrison, Chris Macdonald, Marcelo Actis, Patrick Rodrigues, Darcie J. Miller, Judith Souphron, Steven M. Lewis, Igor Kurinov, Naoaki Fujii, Michal Hammel, Robert Piper, Brian Kuhlman, Brenda A. Schulman

College of the Pacific Faculty Articles

Ubiquitination by HECT E3 enzymes regulates myriad processes, including tumor suppression, transcription, protein trafficking, and degradation. HECT E3s use a two-step mechanism to ligate ubiquitin to target proteins. The first step is guided by interactions between the catalytic HECT domain and the E2∼ubiquitin intermediate, which promote formation of a transient, thioester-bonded HECT∼ubiquitin intermediate. Here we report that the second step of ligation is mediated by a distinct catalytic architecture established by both the HECT E3 and its covalently linked ubiquitin. The structure of a chemically trapped proxy for an E3∼ubiquitin-substrate intermediate reveals three-way interactions between ubiquitin and the bilobal HECT …