Ligand-Receptor Interactions For Supramolecular Disassembly With Applications In Screening And Drug Delivery, Diego F. Amado Torres

Diego Amado Torres

Proteins have the capacity to bind specific sets of compounds known as ligands, these are small molecules with a recurrent theme in their molecular design that is a characteristic exploited here to (i) identify particular affinities of small molecules for proteins with the aim of using them as ligands, inhibitors, or targeting moieties in more complex systems by means of a methodology that screens small molecules based on protein affinity; (ii) decorate a self-assembling supramolecular system at different positions, making it responsive to a complementary protein with the aim of exploring differences in disassembly and sensitivity of the release of ...

Initial Characterization Of A Conserved Active Site Residue For The Cdc34 Ubiquitin Conjugating Enzyme, Arvin Akoopie

Theses

Ubiquitin-conjugating enzymes (E2s) covalently modify protein substrates with ubiquitins. The active site cysteine residues on E2s are essential for catalyzing the transfer of ubiquitin from the E2 active site onto the protein substrate, however there is a limited amount of information available concerning additional active site residues for E2s that may also participate in catalysis. Cdc34 is an essential E2 that has merited the lion’s share of attention for biochemical analysis of the E2 family. Previous phylogenetic analysis of Cdc34 amino acid sequences has identified an invariably conserved histidine residue close to the active site cysteine in the primary ...

Application Of Magnetic “Fishing” And Mass Spectrometry For Function-Based Assays Of Biomolecular Interactions, Meghan J. Mcfadden

Open Access Dissertations and Theses

The human interactome presents a goldmine of potentially powerful therapeutic targets, yet very few small molecule modulators of protein-protein interactions (PPI) have been identified. PPI pose a particular challenge for drug discovery, and one of the major obstacles to fully exploiting these interactions is a lack of appropriate technologies to screen for modulating compounds. This thesis aims to address the need for function- based approaches that target PPI by using magnetic beads (MB) and mass spectrometry (MS) to develop efficient assays to monitor these interactions and their modulation by small molecules. The work begins with the validation of a novel ...

The Wet Adhesion Of Polyvinylamine To Cellulose, John-Louis Diflavio

Open Access Dissertations and Theses

A systematic investigation of Polyvinylamine (PVAm) as a strength-enhancing polymer for wet paper was undertaken through the development of a new test method that simulates the influence of polymers on fibre-fibre bonding in paper. Pairs of wet regenerated cellulose membranes were laminated using the paper strength-enhancing polymer as the lamination adhesive. The resulting laminates served as a physical model for fibre-fibre bonds in paper and the wet laminate strength was determined by ninety degree peeling experiments. Key experimental parameters and sources of error were identified.

The mechanism of PVAm paper wet strength enhancement was explored by the wet cellulose delamination ...

Direct Infusion Lipidomics: Profiling The Lipidome Of A Composite Tailings Reclamation Site, Paul A. Hodgson

Open Access Dissertations and Theses

The comprehensive analysis of intact lipids (called lipidomics) can provide information about the presence of microbial communities in an ecosystem and assist in understanding the biogeochemistry in that system. In previous work we had developed a method to determine the profiles of eight phospholipid classes in a soil microorganism by direct-infusion electrospray mass spectroscopy using tandem mass spectrometry. The work done in this study encompasses first the optimization of previous methodology for use with water and sediment samples containing low concentration of phospholipids and large amounts of organic contaminants and secondly the application of this method to the analysis of ...

Multinuclear Nmr Spectroscopy Methods For The Study Of Structure And Dynamics In Solid-State Electrolytes For Lithium Ion Batteries, Tara L. Spencer Noakes

Open Access Dissertations and Theses

This thesis evaluates several solid-state NMR spectroscopy approaches to studying lithium ion dynamics in solid-state electrolytes. With the goal of reducing the risks associated with current liquid electrolytes, solid-state electrolytes provide non-flammable materials that are also stable against attack by cathode and anode materials. Solid-state NMR spectroscopy offers a versatile method to determine structural details and can also provide information about ion mobility in solid-state electrolytes. Challenges involved in the study of solid-state electrolytes include the difficulty in distinguishing between ^6,7Li resonances due to the small chemical shift range of diamagnetic lithium species. The NMR methods selected in ...

Mechanistic Aspects Of The Complexation, Chalcogen Abstraction And Sigma Bond Insertion Reactions By Transient Silylenes And Germylenes In Solution, Svetlana S. Kostina

Open Access Dissertations and Theses

The complexation reactions of silylenes (SiMe₂, SiPh₂ and SiMes₂) and germylenes (GeMe₂, GePh₂ and GeMes₂) with a series of O-, S-, N- and P-donors have been studied in hexanes solution. The equilibrium constants for complexation of SiMes₂ and GeMes₂ with 7 Lewis bases were determined, and demonstrate that the silylene is more Lewis acidic than the germylene by ca. 1 kcal mol^-1. Diethyl ether reacted with the six tetrellylenes with equilibrium constants that decrease in the order SiPh₂ > SiMe₂ > GePh₂ > GeMe₂ > SiMes₂ > GeMes₂, establishing a ...

Big Horned, Juniper Harrower

The STEAM Journal

Tinta y tinto (Spanish for black ink and red wine)
Through a process of oxidation, reduction, and light manipulation, Juniper stains and colors paper with red wine and a rich black pigment made of the wild harvested mushroom Coprinopsis atramentaria.

Surface, Thermal And Antimicrobial Release Properties Of Plasma-Treated Zein Films, Shashi Kishor Pankaj, C. Bueno-Ferrer, N. N. Misra, Luke O'Neill, A. Jiménez, Paula Bourke, Patrick Cullen

Articles

The effects of dielectric barrier discharge plasma treatment on zein film containing thymol as an active ingredient were evaluated. The plasma discharge was optically characterized to identify the reactive species. A significant increase in the film roughness (p < 0.05) was observed due to the etching effect of DBD plasma, which was correlated with the increase in the diffusion rate of thymol in the food simulant. The diffusion of thymol from the zein film was measured in aqueous solution. The kinetics of thymol release followed the Fick’s law of diffusion as shown by the high correlation coefficients between experimental and theoretical data. No significant change (p > 0.05) was observed for the thermal properties of the antimicrobial films after DBD plasma treatment.

Studies In Asymmetric Synthesis: Supramolecular Catalysis, C-H Activation, And D-Cycloserine Synthesis, Nathan C. Thacker

Student Research Projects, Dissertations, and Theses - Chemistry Department

Rh-catalyzed asymmetric hydrogenation has emerged as a powerful tool for the manufacturing of chiral pharmaceuticals. While the mechanism is well understood, catalyst design a priori is not yet possible. Supramolecular catalysis, the use of non-covalent forces to affect a catalytic process, can afford the catalyst diversity required to uncover efficient catalysts and further our understanding. Using a modular design and self-assembly, a large scale supramolecular catalyst screening in a catalyst scaffold optimization study of rhodium-catalyzed asymmetric hydrogenation was carried out. Analyzing the data yields some new insights into the roles of each module making up the supramolecular catalyst. Perhaps most ...

Surface Functionalization And Bioconjugation Of Nanoparticles For Biomedical Applications, Longyan Chen

University of Western Ontario - Electronic Thesis and Dissertation Repository

Colloidal inorganic nanoparticles (NPs) have been attracting considerable interest in biomedicine, from drug and gene delivery to imaging, sensing and diagnostics. It is essential to modify the surface of nanoparticles to have enhanced biocompatibility and functionality for the in vitro and in vivo applications, especially in delivering locally and recognizing biomolecules. Herein, the goal of this research work is to develop advanced NPs with well-tailored surface functionalities and/or bio-functionality for the applications in cell tracking and analytes detection.

In the first project, quantum dots incorporating with gelatin nanoparticles (QDs-GNPs) have been developed for bioimaging applications. Two different approaches have ...

A Molecular Simulation Study On Micelle Fragmentation And Wetting In Nano-Confined Channels, Mona Habibi

University of Western Ontario - Electronic Thesis and Dissertation Repository

We performed coarse-grained molecular-dynamics (MD) simulations to study the structural and dynamical properties of surfactant micelles in equilibrium and under Poiseuille-like flow in a nano-confined geometry. We used the MARTINI force-field to model the interactions between water molecules, counter-ions, and sodium dodecyl sulfate (SDS) surfactants. SDS surfactant was chosen as the standard model because of its potential application in drug delivery systems. First, we focused on the self-assembly of SDS in equilibrium. To form stable spherical mi- celles, we ran simulations in the isothermal-isobaric ensemble (NPT) on a system of free SDS surfactants, counter-ions and water molecules. We studied the ...

Diphosphine Carboxamide Ligands With Gold(I), Silver(I) And Platinum(Ii), Nasser Nasser

University of Western Ontario - Electronic Thesis and Dissertation Repository

Abstract

This thesis describes the synthesis and characterization of monomeric and polymeric gold(I), silver(I) and platinum(II) complexes containing diphosphine dicarboxamide and pyridine carboxamide donor ligands. The major focus of the project was to characterize these complexes in the solid state using X-ray crystallography. Many of the complexes were also characterized in solution by NMR spectroscopy and electrospray ionization mass spectroscopy.

Chapter one serves as an overall introduction to the topic. Chapter two describes the preparation and characterization of gold(I) and silver(I) complexes with the chiral Trost ligand; R,R-trans-1,2-C₆H₁₀(NHCO-2-C ...

Fabrication Of Cds Nanoparticle Coated Jasmonate Conjugates And Their Interactions With Mammalian Cells, Nazmul Sarker Fcrh '13, Stacey Barnaby Fcrh '11, Ipsita Bannerjee

Fordham Undergraduate Research Journal

In this work, we have grown CdS nanoparticles on jasmonate nanoassemblies biomimetically and examined their interactions with mammalian cells. In general, plants naturally secrete the phytohormone jasmonic acid during development and in response to biotic and abiotic stress as a defense mechanism (Traw and Bergelson 2003; Sembdner and Parthier 1993). We have developed a new class of nanomaterials by utilizing nanoassemblies of the plant phytohormone jasmonic acid (JA) as templates for the growth of quantum dots, which may have potential applications as sensors and may potentially be utilized for bioimaging applications.

Synthesis And Characterization Of Mono- And Di-O-Alkylated Derivatives Of Methyl 3,5-Dihydroxy Benzoate, Michele Paccagnini Fcrh '12, Matthew Tracey Fcrh '11, J. Ryan Combs Fcrh '10, Amy M. Balija

Fordham Undergraduate Research Journal

In the course of searching for monomers for larger macromolecular structures, we attempted the bis-O-alkylation of methyl 3,5-dihydroxy benzoate (1) with (bromomethyl)cyclohexane (2). To our knowledge, no literature procedures have been published on the preparation of ethers by alkylation of a phenol substrate with (bromomethyl)cyclohexane. We were surprised to find that the mono-O-alkylated product was predominantly obtained in this reaction. This finding is in contrast with those reported for alkylations, utilizing benzyl bromide where bis-O-alkylation is the predominant reaction (Yan et al. 2011). Herein we report a convenient synthesis of the bis-alkylated product 3 in good yield.

Selection And Phenotypic Characterization Of A Core Collection Of Brachypodium Distachyon Inbred Lines, Ludmilla Tyler, Johnathan U. Fangel, Alexandra D. Fagerström, Michael A. Steinwand, Ted K. Raab, William Gt Willats, John P. Vogel

Ted K. Raab

The model grass Brachypodium distachyon is increasingly used to study various aspects of grass biology. A large and genotypically diverse collection of B. distachyon germplasm has been assembled by the research community. The natural variation in this collection can serve as a powerful experimental tool for many areas of inquiry, including investigating biomass traits. We surveyed the phenotypic diversity in a large collection of inbred lines and then selected a core collection of lines for more detailed analysis with an emphasis on traits relevant to the use of grasses as biofuel and grain crops. Phenotypic characters examined included plant height ...

Fluctuations In Transient Response Of Adsorption-Based Plasmonic Sensors, Zeljko D. Cupic

Zeljko D Cupic

The basic parameters of a sensor element defining its ultimate performance are sensitivity and intrinsic noise. In plasmonic gas sensors both are determined by refractive index changes due to adsorption and desorption (a–d) of target analyte particles to the sensor active area. In this paper we present a general model that can be simultaneously used to determine sensitivity and intrinsic noise of a plasmonic sensor both during transients and in steady-state and is valid for multi-analyte environments. The model utilizes the conventional probabilistic approach. It is derived without any assumptions about the stochastic nature of the fundamental (a–d ...

Development Of An Enzymatic Digestion Method To Probe The Sequence Specificity Of Carcinogen Adduction In Oligonucleotides, John M. Capece

Chemistry Master's Theses

A carcinogen is defined as any substance, radiation, or radionucleotide that produces cancer through alteration of the metabolic processes in the cell or by directly damaging the cell's DNA. In cases where DNA is damaged, the carcinogen comes into contact with the DNA; the DNA performs a nucleophilic attack on the electrophilic carcinogen, which permanently binds the two. This reaction between carcinogens and DNA generally exhibits sequence selectivity, the recognition of which may be important in understanding their mutagenic activities. A method could be developed to measure the effectiveness of several different DNA repair pathways. Exposing bacterial plasmids to ...

Further Characterization Of A Secreted Lipase From The Human Pathogen Leishmania Donovani By Determining The Effect Of Various Metal Ions On Its Enzymatic Activity., Lana Hoertz

Pell Scholars and Senior Theses

Leishmania donovani, a protozoan parasite, is the causative agent of the often fatal disease visceral leishmaniasis. The current treatments available are minimal and toxic to the patient. It has been shown that these organisms exhibit lipolytic activity during their growth in vitro. Lipases are enzymes that are known to aid in the development and virulence of several pathogenic organisms such as Candida albicans and Staphylococcus warneri. Little information is known, however, about the role of lipases in Leishmania species. We hypothesize that lipase may play a part in Leishmania's ability to survive within the human host as well as ...

Applications Of Cold Plasma Technology In Food Packaging, Shashi Kishor Pankaj, C. Bueno-Ferrer, N. N. Misra, V. Milosavljević, C. P. O’Donnell, Paula Bourke, Kevin Keener, P. J. Cullen

Articles

Cold plasma technology is an emerging, green process offering many potential applications for food packaging. While it was originally developed to increase the surface energy of polymers, enhancing adhesion and printability, it has recently emerged as a powerful tool for surface decontamination of both foodstuffs and food packaging materials. New trends aim to develop in- package decontamination, offering non-thermal treatment of foods post packaging. This paper provides an overview of cold plasma theory, equipment and summarises recent advances in the modification of polymeric food packaging materials along with potential applications in the food industry.