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The Dimerization Kinetics Of Ncad12 With A Mutated Cis-X-Pro Bond, Victoria Mcclearn

Honors Theses

VICTORIA RAE McCLEARN: DIMERIZATION KINECTICS OF NCAD12 P16A (Under the direction Dr. Susan Pedigo) Calcium binding causes a conformational change into a strand swapped dimer for the cadherins. However, regardless of the sequence similarity for Epithelial Cadherin (ECAD) and Neural Cadherin (NCAD), they respond to the presence of calcium differently. For NCAD, the rate of assembly and disassembly depends upon the presence of calcium, whereas for ECAD the rate of exchange is independent of calcium. Studies into a kinetic model to explain the differences between the rates have been recently conducted. It is believed that ECAD uses an X-dimer intermediate …

The Effects Of Hg2+ On Secondary Structures Formed By T-Rich Dna, Zachary Boynton

Honors Theses

Single stranded DNA that forms secondary structures has been a popular area of research in recent years. Much research has also been done in the field of heavy metals binding to DNA. Recently, it has been discovered that mercury in the presence of thymines will form T-HgII-T bonds. It is our hypothesis that single stranded DNA rich in thymine residues will form into a structure similar to i-motifs, formed from C-rich single strands, in the presence of mercury. Based on spectral changes during a mercuric titration, it is evident that mercury induces a structural change in T-rich DNA. We then …

Method Development For The Detection And Quantitation Of Illicit Drugs In Fingerprints Using Matrix-Assisted Laser Desorption Ionization-Mass Spectrometry, Madison Roussel

Honors Theses

The purpose of this research was to develop a method for the detection and quantitation of caffeine and 11-nor-9-carboxy-Δ9- tetrahydrocannabinol in fingerprints using matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). The matrix used was 2,5-dihydroxybenzoic acid (DHB). The presence of the analytes was confirmed by analysis using liquid chromatography-mass spectrometry (LC-MS). 11-nor-9-carboxy-Δ9- tetrahydrocannabinol was chosen as the drug of interest because it is the major metabolite of tetrahydrocannabinol, the main psychoactive component of marijuana. Marijuana's popularity as a recreational drug continues to increase with its legalization and decriminalization across the country. It is critical to establish methods for the quantification …

X-Dimer Mutations And Their Effects On The Folding Stability And Assembly Of Ecad12 At The K14-D138 Interface, Martha Kaitlyn Coghlan

Honors Theses

Classical cadherins were first identified by their function in mediating calcium-dependent cellular adhesion and constitute a large family of cellular adhesion receptor proteins whose differential binding is central to the development and maintenance of tissue architecture. The interface underlying the binding interaction reveals that all classical cadherins share a common adhesive interface in which the portion of the β-A strand closest to the N-terminus is swapped between EC1 domains of the adhesive partner protomers. A second dimeric configuration, known as the 'X-dimer', is the face-to-face association of two protomers in which their orientation is dictated by three symmetrical noncovalent interactions …

Characterization Of Epithelial Cadherin Domain 1, Molly Edmondson

Honors Theses

Cadherins are a family of cell-surface glycoproteins that aid in cell adhesion between two proximal cells. The characteristic cadherin extracellular structure consists of five ~100 amino acid domains connected by seven-residue linker regions. Cadherins mediate adhesion via adherens junctions by forming a strand-swapped structure between identical protomers from apposing cells. Upon calcium binding, the swapping of the N- terminal strands between protomers allows for the symmetrical docking of a conserved tryptophan residue in the N-terminal strand into the hydrophobic pocket of its partner protomer. The two most-well-studied members of the classical cadherin family are Neural- (N-) and Epithelial- (E-) cadherin. …

Development Of Methods For Determining Dry Deposition Of Mercury Using An Ion-Exchange Membrane: Relative Rates Of Mercury Dry Deposition At Sardis, Enid, And Grenada Lakes, Ruiqi Feng

Honors Theses

This research focuses on studies developing methods to measure dry deposition of mercury (Hg) using an ion-exchange (IX) membrane to capture gaseous mercury species in the air. Mercury is a toxic heavy metal that is spread globally through the atmosphere. Atmospheric Hg deposits to terrestrial and aquatic ecosystems through wet and dry deposition. While routine methods have been developed to study wet deposition of Hg, measuring dry deposition of Hg is more problematic and often overlooked. In this study, we developed an inexpensive means to deploy a polyethersulfone cation exchange membrane in the field by dangling it within a polycarbonate …

Effects Of Synthetic Blood Plasma On Calcium Dependent Dimerization Of Ncad12, Brent Treadway

Honors Theses

Neural Cadherin (NCAD) is one of three Type 1 vertebral classical cadherins that function as the primary transmembrane component in cell-to-cell interactions at adherens junctions. Adhesive interactions mediated by this protein are calcium dependent with three calcium-binding sites between each of its five extracellular domains. NCAD is very important in many cell-to-cell interactions because of its function in development and in immune and neurological synapses. Generally, in vitro studies of calcium dependent dimerization of NCAD are conducted in a nonphysiological buffer (NaCl + HEPES: SEC buffer). In order to study dimerization in more physiologically relevant conditions, I created a synthetic …

A Study Of The Impact Of Ph On The Structure And Stability Of Epithelial Cadherin, Catherine Abadie

Honors Theses

Epithelial (E-) cadherin is a transmembrane protein whose function lies in cell-to-cell adhesion. It is a transmembrane component of adherens junctions of epithelial tissues, thereby connecting the actin cytoskeletons of adhered cells. It has five extracellular domains, a small transmembrane portion, and a cytoplasmic tail. The molecule must bind calcium in order to form an adhesive dimer with a cadherin molecule emanating from an adjacent cell. Cancer of the epithelial tissue, carcinoma, is accompanied by acidification of the tissue and a loss in cell adhesion. The long-term goal of this project is to determine the effect of a decrease in …

The Spectroscopic Characterization Of Newly Developed Emissive Materials And The Effects Of Environment On Their Photophysical Properties, Louis Edward Mcnamara

Electronic Theses and Dissertations

The development of new materials capable of efficient charge transfer and energy storage has become increasingly important in many areas of modern chemical research. This is especially true for the development of emissive optoelectronic devices and in the field of solar to electric energy conversion. The characterization of the photophysical properties of new molecular systems for these applications has become critical in the design and development of these materials. Many molecular building blocks have been developed and understanding the properties of these molecules at a fundamental level is essential for their successful implementation and future engineering. This dissertation focuses on …

Synthetic Oligodeoxynucleotide Purification Via Catching By Polymerization, Suntara Fueangfung

Dissertations, Master's Theses and Master's Reports - Open

Large quantities of pure synthetic oligodeoxynucleotides (ODNs) are important for preclinical research, drug development, and biological studies. These ODNs are synthesized on an automated synthesizer. It is inevitable that the crude ODN product contains failure sequences which are not easily removed because they have the same properties as the full length ODNs. Current ODN purification methods such as polyacrylamide gel electrophoresis (PAGE), reversed-phase high performance liquid chromatography (RP HPLC), anion exchange HPLC, and affinity purification can remove those impurities. However, they are not suitable for large scale purification due to the expensive aspects associated with instrumentation, solvent demand, and high …

Design And Development Of Bodipy-Based Fluorescent Probes For Sensing And Imaging Of Cyanide, Zn (Ii) Ions, Lysosomal Ph And Cancer Cells, Jingtuo Zhang

Dissertations, Master's Theses and Master's Reports - Open

BODIPY (4,4-Difluoro-3a,4a-diaza-s-indacene) dyes have gained lots of attention in application of fluorescence sensing and imaging in recent years because they possess many distinctive and desirable properties such as high extinction coefficient, narrow absorption and emission bands, high quantum yield and low photobleaching effect. However, most of BODIPY-based fluorescent probes have very poor solubilities in aqueous solution, emit less than 650 nm fluorescence that can cause cell and tissue photodamages compared with bio-desirable near infrared (650-900 nm) light. These undesirable properties extremely limit the applications of BODIPY-based fluorescent probes in sensing and imaging applications. In order to overcome these drawbacks, we …

On The Protective Properties Of Glycine Based Osmolytes In A Thiol Reducing Environment, John Michael Hausman

Dissertations, Master's Theses and Master's Reports - Open

The protective properties of osmolytes have been studied intently for decades. Originally used to aid in the crystallization of proteins in x-ray diffraction studies, these cosolvents have been shown to reverse protein denaturation and aggregation. Osmolytes aid extremophiles in surviving harsh environments by preferentially excluding themselves from the surface of the protein, thus directing water molecules to the protein’s surface. These osmolytes are naturally found in many health foods and also in many daily use products such as shampoo. Due to their osmoprotective effect their use in everyday consumer product is increasing. Consumers also supplement their diets with thiol-based antioxidants …

Biodegradable Poly(Ester Urea's) Scaffold Sponges Containing Platelet-Rich Plasma For Targeted Tendon-Bone Fixation, Alex B. Ellenberger Mr.

Williams Honors College, Honors Research Projects

In this report the synthesis and characterization of L-valine and L-isoleucine poly(ester ureas) (PEUs) for future use in the synthesis of biodegradable PEUs sponges will be discussed. The method of monomer and polymer synthesis will be explained along with the characterization of the monomer and polymer products. This characterization will be done by the use of Nuclear Magnetic Resonance (NMR) and Size Exclusion Chromatography (SEC). NMR is a quick and convenient method for determining structure and purity of the monomer and polymer products. SEC gives the number average molecular weight, which is the statistical average molecular weight of all the …

Determination Of The Structure Of Sphingomyelin By Tandem Mass Spectrometry And Matrix - Assisted Laser Desorption/Ionization, Antonio Ganios

Williams Honors College, Honors Research Projects

Mass spectrometry is a method that uses masses to determine the structure of a compound. This is completed by first charging the compound until it is a cation or anion, and then its molecular weight can be determined by measuring a mass to charge ratio. The focus of this study was determination of sphingomyelin’s structure. The purpose of this was that sphingomyelin has been shown to play a critical role in many biological pathways and being able to identify this lipid could prove to be beneficial for preventative medicine. Utilizing electrospray ionization (ESI) Quadruple-Time-of-flight (Q-TOF) mass spectrometry on a Waters …

Humidity And Rest Period Effects On Viscid Silk Recovery, Catherine Donley

Williams Honors College, Honors Research Projects

Spider silk applications, and applications of composite materials generally, are limited due to lack of recovery once damaged. Viscid silk, however, is known to have self-healing capabilities which restore, at least partially, its initial properties. If maximized, this ability could potentially increase viscid silk’s practicality and ultimately, provide insight into a self-healing system of use in synthetics. To that end, samples of viscid silk spun by female Larinioides cornutus spiders were tested via cyclical loading at 3 different relative humidities, with 3 different rest period lengths between complete cycles. Data from previously-performed tensile tests conducted at the same 3 humidities …

The Effects Of Substrate Roughness In Air And Water On The Gecko Adhesive System, Amanda Palecek

Williams Honors College, Honors Research Projects

In an effort to better understand the fascinating gecko adhesive system, scientists have long tested the abilities of the gecko in controlled conditions that mimic the gecko’s native environment. The effects of humidity, environmental temperature, and exposure to water have all been tested. Roughness, however has not been studied in great detail. Surfaces of varying roughnesses are all over the gecko’s natural environment. We tested geckos on hydrophilic silicon carbide sandpapers of varying roughnesses in both air and water to attempt to better study the effects of roughness on gecko adhesion. When tested on the rougher (1 µm) surface, the …

Gene Expression Of Tissue-Engineered Distal Phalanx Models Utilizing Polymer Scaffolds With Hydroxyapatite And Beta-Tricalcium Phosphate, Kristrun H. Kristinsdottir, William J. Landis Ph.D., Robin Jacquet M.S.

Williams Honors College, Honors Research Projects

Tissue engineering is a scientific methodology that provides the means for fabrication of vital tissues in a laboratory with the ultimate goal of translating the tissue to a patient in a clinic. It is a desirable technique in clinical medicine because it eliminates the need for patient tissue grafts and transplants, which have the potential for donor site morbidity and rejection. In tissue engineering, the scaffolding material, typically a polymer upon which tissue is grown, is important. The goal of this research is to investigate optimization of tissue-engineered polymer scaffold constructs for cell proliferation and gene expression. This work includes …

The Biogeochemistry Of Elemental Sulfur Contaminated Soils: Insights Into Effective Remediation, Michael Ryan Mctee

Graduate Student Theses, Dissertations, & Professional Papers

Soil contamination that results from elemental sulfur (S⁰) deposition is a new occurrence. Elemental sulfur is stockpiled as a byproduct from the oil and gas industry and is deposited by biodegradable trap and skeet targets at shooting ranges. Chemolithotrophs and mixotrophs can oxidize S⁰ to H₂SO₄. Consequently, in areas where excess S⁰ is deposited or stockpiled, soils can acidify to pH values observed with acid mine drainage.

I studied S⁰ contamination at a former sporting clay range. For seven years, the range used biodegradable trap and skeet targets that contained S …

A Rapid And High Content Assay That Measures Cyto-Id-Stained Autophagic Compartments And Estimates Autophagy Flux With Potential Clinical Applications, Sujuan Guo, Yanping Liang, Susan F. Murphy, Angela Huang, Haihong Shen, Deborah F. Kelly, Pablo Sobrado, Zhi Sheng

Chemistry Faculty Research & Creative Works

The lack of a rapid and quantitative autophagy assay has substantially hindered the development and implementation of autophagy-targeting therapies for a variety of human diseases. To address this critical issue, we developed a novel autophagy assay using the newly developed Cyto-ID fluorescence dye. We first verified that the Cyto-ID dye specifically labels autophagic compartments with minimal staining of lysosomes and endosomes. We then developed a new Cyto-ID fluorescence spectrophotometric assay that makes it possible to estimate autophagy flux based on measurements of the Cyto-ID-stained autophagic compartments. By comparing to traditional autophagy approaches, we found that this assay yielded a more …

The Antitumorigenic Function Of Egfr In Metastatic Breast Cancer Is Regulated By Expression Of Mig6, Michael Wendt, Whitney K. Williams, Pete E. Pascuzzi, Nikolas G. Balanis, Barbara J. Schiemann, Cathleen R. Carlin, William P. Schiemann

Borch Department of Medicinal Chemistry and Molecular Pharmacology Faculty Publications

Numerous studies by our lab and others demonstrate that epidermal growth factor receptor (EGFR) plays critical roles in primary breast cancer (BC) initiation, growth and dissemination. However, clinical trials targeting EGFR function in BC have lead to disappointing results. In the current study we sought to identify the mechanisms responsible for this disparity by investigating the function of EGFR across the continuum of the metastatic cascade. We previously established that overexpression of EGFR is sufficient for formation of in situ primary tumors by otherwise nontransformed murine mammary gland cells. Induction of epithelial-mesenchymal transition (EMT) is sufficient to drive the metastasis …

Synthesis And Characterization Of Imidazolium Salt Derivatives For Anti-Tumor Activity, Ryan W. Pearce

Williams Honors College, Honors Research Projects

Several aldehydes (butanal, pentanal, hexanal, 4-hydroxybenzaldehyde) were reacted with 1,3-bis(naphthalen-2-ylmethyl)-imidazolium bromide (1) to produce novel C² substituted imidazolium salts for the potential use against non-small cell lung cancer in humans. Compounds 2-(1-hydroxypentyl)-1,3-bis(naphthalen-2-ylmethyl)-imidazolium bromide (3) and 2-(1-hydroxyhexyl)-1,3-bis(naphthalen-2-ylmethyl)-imidazolium bromide (5) were successfully synthesized with structures supported by NMR and mass spectrometry. Characterization by ¹H NMR showed evidence of 1 in both compounds. The tumor cell growth inhibition of 3 against non-small cell lung cancer lines NCI-A549, NCI-H460, HCC827, and NCI-H1975 was tested and found to be comparable to cisplatin as measured by MTT assay. …

Gold Nanomolecules : Developing Synthetic Protocols, Characterization And Investigation Of Ligand Effects On Structure And Properties, Praneeth Reddy Nimmala

Electronic Theses and Dissertations

The term "Nano" in chemistry refers to particles/molecules in the size range 1 to 100 nm. Gold nanoparticles were used in ancient times in making decorative glass as they produce vibrant, size dependent, colors upon interaction with light. Gold is a preferred choice of metal for the synthesis of nanoparticles mainly due to its inertness to atmospheric conditions and most chemicals. Gold thiolate nanomolecules, which is the primary focus of this dissertation research, are chemical molecules with a fixed number of gold atoms and organo-thiolate ligands. They are of the form Aux(SR)y and possess molecule-like properties as a result of …

Synthetic Study Of Karlotoxins And Investigation Of Alpha-Diaminoboryl Carbanion Chemistry, Yusuke Takahashi

Electronic Theses and Dissertations

Karlotoxins (KmTxs), produced by a toxic marine/estuarine phytoplankton, the dinoflagellate Karlodinium veneficum, are known to be ichthyotoxic, thus being associated with numerous fish deaths events worldwide. They have also been reported to show a variety of biological activities such as hemolytic, cytotoxic, and anti-fungal activities. Recently, the Hamann group successfully assigned the absolute configurations of KmTx2, the first complete structure elucidation among the congeners. In a structural sense, karlotoxins are a family of linear polyketides with three distinctive regions; a bis-tetrahydropyran core fragment, a long, highly oxygenated carbon chain, and a lipophilic chlorodiene unit. Such potent biological activities as well …

Synthesis And Anti-Proliferative Activity Of N,N’-Bis(Arylmethyl)Benzimidazolium Salts, Travis M. Williams

Williams Honors College, Honors Research Projects

A series of N,N’-bis(arylmethyl)benzimidazolium salts with hydrophilic and lipophilic substituents have been synthesized, characterized, and tested against select non-small cell cancer cell lines. Substituent variations on the imidazole ring have shown that lipophilicity and hydrophilicity can influence the imidazolium salts’ anti-proliferative activity and aqueous solubility.

Heterometallic Titanium–Gold Complexes Inhibit Renal Cancer Cells In Vitro And In Vivo, Jacob Fernandez-Gallardo, Benelita T. Elie, Tanmoy Sadhukha, Swayam Prabha, Mercedes Sanau, Susan A. Rotenberg, Joe W. Ramos, Maria Contel

Publications and Research

Following recent work on heterometallic titanocene–gold complexes as potential chemotherapeutics for renal cancer, we report here on the synthesis, characterization and stability studies of new titanocene complexes containing a methyl group and a carboxylate ligand (mba ¼ S–C6H4–COO) bound to gold(I)-phosphane fragments through a thiolate group [(h-C5H5)2TiMe(m-mba)Au(PR3)]. The compounds are more stable in physiological media than those previously reported and are highly cytotoxic against human cancer renal cell lines. We describe here preliminary mechanistic data involving studies on the interaction of selected compounds with plasmid (pBR322) DNA used as a model nucleic acid, and with selected protein kinases from a …

Mercury Methylation Potentials In Sediments An Ancient Cypress Wetland Using Species-Specific Isotope Dilution-Gc-Icp-Ms: Analytical Method Development And The Effect Of Sorbent Amendments, Derek Davin Bussan

Electronic Theses and Dissertations

A novel method was developed to measure mercury (Hg) directly in environmental solids using inductively coupled plasma mass spectrometry (ICP-MS) with online sample ashing. The method combines a direct mercury analyzer (DMA) that is based on sample combustion, Hg pre-concentration by amalgamation with gold, and atomic absorption spectrometry (AAS), with a high resolution ICP-MS. Unlike AAS, the ICP-MS is capable of individual isotope measurements allowing for accurate quantitation by isotope dilution mass spectrometry (IDMS) and for isotope tracer experiments. The method was validated using certified reference materials including sediment (NIST 2709), leaves (NIST 1547), and fish-muscle (DORM-3), with recoveries within …

Titanium Dioxide Nanoparticles Trigger Loss Of Function And Perturbation Of Mitochondrial Dynamics In Primary Hepatocytes, Vaishaali Natarajan, Christina L. Wilson, Stephen L. Hayward, Srivatsan Kidambi

Department of Chemical and Biomolecular Engineering: Faculty Publications

Titanium dioxide (TiO₂) nanoparticles are one of the most highly manufactured and employed nanomaterials in the world with applications in copious industrial and consumer products. The liver is a major accumulation site for many nanoparticles, including TiO₂, directly through intentional exposure or indirectly through unintentional ingestion via water, food or animals and increased environmental contamination. Growing concerns over the current usage of TiO₂ coupled with the lack of mechanistic understanding of its potential health risk is the motivation for this study. Here we determined the toxic effect of three different TiO₂ nanoparticles (commercially available …

Cip10 Optimization For 4,4-Methylene Diphenyl Diisocyanate Aerosol Sampling And Field Comparison With Impinger Method, Silvia Puscasu, Simon Aubin, Yves Cloutier, Philippe Sarazin, Huu Van Tra, Sébastien Gagné

Études primaires

4,4-methylene diphenyl diisocyanate (MDI) aerosol exposure evaluation in spray foam insulation application is known as being a challenge because the spray foam application actually involves a fast-curing process. Available techniques are either not user-friendly or are inaccurate or not validated for this application. To address these issues, a new approach using a CIP10M was developed to appropriately collect MDI aerosol in spray foam insulation while being suitable for personal sampling. The CIP10M is a commercially available personal aerosol sampler that has been validated for the collection of microbial spores into a liquid medium. Tributylphosphate with 1-(2-methoxyphenyl)piperazine (MOPIP) was introduced into …

Determination Of Triglycidyl Isocyanurate From Air Samples By Ultra-Performance Liquid Chromatography Coupled With Coordination Ion Spray Mass Spectrometry, Sébastien Gagné, Marielle Carrier, Simon Aubin

Études primaires

Rationale

Ultra-performance liquid chromatography (UPLC) coupled with coordination ion spray tandem mass spectrometry was used for the analysis of air samples containing triglycidyl isocyanurate. The method is not affected by any chromatographic interference and the filter extract is compatible with the UPLC system, as opposed to approaches using high-performance liquid chromatography coupled with ultraviolet detection and gas chromatography coupled with mass spectrometry.

Methods

Accu-cap^™ filters that had sampled triglycidyl isocyanurate were extracted using a mixture of acetonitrile/acetone (95/5) diluted with 3 volumes of water and were then analyzed. The mass spectrometry method uses sodium as the alkali adduct complexing …

Inhibition Of Toxic Iapp Amyloid By Extracts Of Common Fruits, David Moffet

Chemistry and Biochemistry Faculty Works

The aggregation of the 37-amino acid polypeptide islet amyloid polypeptide (IAPP, amylin), as either insoluble amyloid or as small oligomers, appears to play a direct role in the death of pancreatic β-islet cells in type 2 diabetes. It is believed that inhibiting the aggregation of IAPP may slow down, if not prevent entirely, the progression of this disease. Extracts of 13 different common fruits were analyzed for their ability to prevent the aggregation of amyloidogenic IAPP. Thioflavin T binding, immuno-detection and circular dichroism assays were performed to test the in vitro inhibitory potential of each extract. Atomic force microscopy was …