Biochemistry, Biophysics, and Structural Biology Commons^™

A Guided Inquiry To The Bromination Of Alkenes: An Effort To Foster Student Understanding Of Thin Layer Chromatography In The Organic Chemistry Laboratory, Casey Wright

Honors Theses

Many of the chemistry laboratories taught at Western Michigan University are “cookbook” labs, meaning that students are given an instruction manual with a prescribed set of instructions and a predicted outcome. Therein we present an introductory organic chemistry laboratory experiment to reinforce the student understanding of Thin Layer Chromatography which utilizes a guided inquiry format as part of an effort to move toward discovery based learning in our organic chemistry curriculum. Educational research was performed on classroom artifacts collected from the laboratory. We were able to gain an understanding of the struggles students face in applying general chemistry content knowledge …

Determining The Concentration Of Nitric Oxide In Solvent, Emily-Jean E. Bankes

Honors Theses

The body creates nitric oxide (NO) for signaling. One way that researchers study NO signaling is through the use of model complexes, or molecules that have the same metal ion and a similar molecular shape as biological molecules and are easy to synthesize. Currently researchers have limited ways to deliver precisely-known small quantities of NO to an experiment where they are trying to investigate NO-binding to a transition metal complex. A peak shift in the absorption spectrum at ~530 nm makes it possible for UV-Vis spectroscopy to observe NO binding to cobalt tetraphenylporphyrin (CoTPP). This makes it possible to measure …

Computational Studies Of Paradifluorobenzene Cations And Hydrogen Cyanide Molecule, John C. Rowe Iv

Honors Theses

Polycyclic aromatic hydrocarbons (PAHs) are hypothesized to comprise a significant portion of interstellar carbon identified from the Diffuse Interstellar Bands (DIBs). Gas phase cation-molecule reactions between compounds that previously existed as weakly bound species provides the best explanation for the emergence of PAHs in the interstellar medium (ISM). In this work, we use computational methods to characterize one of these weakly-bound systems. We discovered that intramolecular charge distribution (calculated using the Natural Population Analysis) dictate the complexes formed between a paradifluorobenzene cation and either one or two HCN molecules. Additionally, the relative stabilities of the complexes and the binding energies …

Characterization Of Catecholamine Receptors And Transporters In Murine Macrophages, Elizabeth Gonye

Honors Theses

Macrophages are a critical part of the immune response. When circulating monocytes move into tissues they differentiate int macrophages to mount the first line of defense against pathogens.

Calcium (Ii) Catalyzed Nitrone Additions, Elizabeth A. Congdon

Honors Theses

Calcium(II) complexes have be shown to be successful catalysts for nitrone reactions. The addition of n-­‐methyl and n-­‐phenyl nitrones to donor-­‐acceptor cyclopropanes was achieved with calcium triflate (Ca(OTf). Differentially substituted tetrahydro-­‐1,2-­‐oxazines were synthesized in good to excellent yields. Calcium triflate was also found to catalyze the addition of silyl enol ethers to n-­‐phenyl nitrones along the Mukaiyama-­‐Mannich addition pathway. B-­‐amino carbonyls were synthesized from a variety of substituted nitrones. Bulky and cyclic silyl enol ethers were also found to be reactive, the products of which were isolated in good to excellent yields.

Impact Of Vector Range Expansion On Pathogen Transmission Dynamics Of Lyme Disease In Southwestern Virginia, Bishan Bhattarai

Honors Theses

Blacklegged ticks, Ixodes scapularis is the primary vector of Lyme disease in eastern United States. Borrelia Burgdorfei, the etiological agent of Lyme disease is transferred by ticks of Ixodes species. In recent years, its congener, Ixodes affinis has been expanding its range northwards from its southern population. We were interested in studying how the introduction of this new vector affected the interaction between the pathogen genotype and the host. We hypothesized that differential host use by I. affinis and I. scapularis would partly explain observed differences in B. burgdorferi infection prevalence and genotypic structure in southeastern Virginia. The result …

Development Of A Chemical Genetic Screen To Determine Synergistic Compounds With Laromustine In Treating Glioblastoma Multiforme Cultured Cells, Ryan Weeks

Honors Theses

Laromustine is a chemotherapeutic sulfonylhydrazine prodrug used in clinical trials to treat acute myeloid leukemia (AML) and glioblastoma multiforme (GBM). While treatment of AML with laromustine has more demonstrative clinical success, there are enough promising data against GBM to pursue additional pre-clinical and clinical experiments. To determine the synergistic effects caused by treating cultured GBM cells with laromustine and a library of FDA-approved compounds, a chemical genetic screen was developed. To optimize the screen, optimal cultured GBM cell seed density, growth period and maximum well capacity were determined. The treatment period for a lethal dose of laromustine in cultured GBM …

Granulins As Inflammatory Mediators In Alzheimer Disease, Randi G. Reed

Honors Theses

Alzheimer disease (AD) is a neurodegenerative disorder characterized by severe memory deficit and cognitive decline among the elderly. This degeneration is caused by the aggregation and deposition of a protein called amyloid-β (Aβ) in the brain. Aggregation of Aβ causes neuroinflammation in addition to other toxic events. However, it is unclear whether inflammation from an external source, such as from a traumatic brain injury (TBI), could trigger Aβ aggregation. In this context, several pro-inflammatory mediators such as cytokines and chemokines have been suspects. It is now hypothesized that a group of proteins called granulins (Grns) are unique inflammatory mediators that …

Isolation Of Microbial Nrps And Pks Gene Clusters For Natural Product Isolation, Danielle N. O'Hara

Honors Theses

Greater than 99% of microbes living in the environment are uncultivable due to their complex nutrient and temperature requirements for growth. These microorganisms present a potential source of natural products that could be developed for biotechnological and pharmaceutical uses. Microorganisms with phosphopantetheinyl transferase (PPTase) activity are of high interest due to the role PPTase plays in activating non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) gene clusters. These gene clusters produce multi-enzymatic, multi-domain megasynthases that produce complex natural products utilized by the host organism for selective advantages. This study isolated genomic DNA from soil samples collected from the University of …

An Investigation Of Bag3 Knockdown And Its Effects On The Cytotoxicity Of Laromustine, Colin Sheehan

Honors Theses

Laromustine is a sulfonylhydrazine anticancer prodrug whose main cytotoxic arises from its ability to interfere with DNA replication of dividing cells. Multiple studies have suggested that Laromustine induces a form of cell death known as apoptosis. In a previous study investigating the mechanism of apoptosis, bcl2-associated athanogene 3 (BAG3) demonstrated significant upregulation in the presence of Laromustine. Given its anticancer ability, we selected BAG3 as a target for further investigation. BAG3 knockdown through transient shRNA transfections was performed in U138 glioblastoma multiforme cells and verified using qRT-PCR analysis. Finally, cell death assays were used to assess Laromustine’s cytotoxic effect on …

An Nmr-Guided Approach To The Isolation Of Secondary Metabolites From Nrps And Pks Gene Clusters, Connor Craig

Honors Theses

Secondary metabolites continue to offer a promising source of novel chemical entities with therapeutic bioactivities. Our research aims to isolate secondary metabolites produced by non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) constructs. A metagenomic library was created from the marine bacterium Pseudoalteromonas sp., which was isolated from the Chesapeake Bay sponge Halichondria bowerbanki. Using a functional screen for PPTase activity we were able to identify colonies that contained NRPS and PKS gene clusters. Cultures of this microbe have been produced and analyzed using a combination of chromatography and 1H, 13C, HMBC, HSQC, COSY, AND NOESY NMR spectra. …

Development Of A Genetic Over-Expression System For The Freshwater Sponge Ephydatia Muelleri, Joe Walsh

Honors Theses

The aim of this work is to develop an over-expression system for Ephydatia muelleri. Preliminary work by Klaske Schippers (Schippers, 2013) showed sponges were induced to transcribe reporter genes driven by the widely used cytomegalovirus promoter (CMV). Building off Schippers work, newly identified native Ephydatia promoters were identified from the genome and verified to drive expression ofreporter genes. Validated over-expression vectors and transfection technology will allow researchers around the world who are working with this organism to ask questions about cell specification, gene regulation and animal development.

The Use Of A Small Molecule To Improve The Thermostability Of Dna Junctions, Arik Shams

Honors Theses

The short-term goal of this research project is to employ small molecules as a means to stabilize four-way DNA junctions (4WJs) composed of natural DNA and chimeric nucleic acids. The long-term goal of the project is utilizing the 4WJs as extracellular therapeutic inhibitors of DNA binding proteins [i.e. Histones and High Mobility Group Protein B (HMGB1b)]. A number of studies have shown that classical intracellular DNA-binding proteins have a variety of deleterious side-effects when present in the extracellular milieu. In order to develop a successful 4WJ therapeutic, we are focused on using modified nucleic acids to enhance the stability of …

Cloning, Expression And Interaction Studies Of The Potential Rubisco Activase Cbbq, Salma A. Dawoud

Honors Theses

Carboxysomes are polyhedral microcompartments found in all cyanobacteria and in many chemoautotrophs. Within their shell they contain the enzyme ribulose-1, 5-bisphosphate carboxylase/oxygenase (RubisCO), which fixes CO₂. Downstream of the carboxysome operon there is another gene cluster containing several genes that may enhance carboxysome function. Two of these genes, cbbQ and cbbO, encode potential RubisCO activases. Using recombinant CbbQ and CbbO protein, and RubisCO isolated from carboxysomes the interaction between these proteins was studied. The CbbO and CbbQ proteins were both His tagged, allowing them to be purified with Ni²⁺-NTA column chromatography. Each of these tagged …

Formyl Group Activation Of Bromopyrrole Suzuki Cross-Coupling: Application To A Formal Synthesis Of Lamellarin G Trimethyl Ether, Andrew Harrison

Honors Theses

Many biologically interesting compounds have been isolated from marine natural products, many of which contain characteristic pyrroles. Compounds such as polycitones, storniamides, ningalins, and lamellarins have been of particular interest for synthesis due to their vast pharmaceutical potential including the ability to fight tumors as well as induce cytolysis of drug resistant cancer cell lines. Previous studies on the synthesis of Lamellarin G trimethyl ether by the Gupton Group have relied upon vinylogous amide derivatives as building blocks.2 A new pathway utilizing a formylated pyrrole ring provides an interesting method for the synthesis of Lamellarin G trimethyl ether. Regioselective Suzuki …

Optimization Of A Chemical Genetic Screen To Identify Druggable Targets In U138 Cells Treated With Laromustine, Kathryn Coe

Honors Theses

Laromustine is an experimental sulfonylhydrazine prodrug used in late-stage clinical studies against acute myeloid leukemia (AML) and glioblastoma multiforme (GBM). Despite initial promise for both indications, clinical trials for GBM have not been as successful as those for AML. To investigate methods for improving the effectiveness of laromustine in GBM and to learn more about the mechanism of action of laromustine, a chemical genetic screen will be conducted to identify agents that sensitize GBM cells to the anti-proliferative effects of laromustine. The library, which will include approximately 450 FDA-approved drugs, will be screened using a newly optimized high throughput assay …

A Conservative Isoleucine To Leucine Mutation Of Klentaq1 Dna Polymerase 1 Induces Conformational Change For Cold-Sensitive Phenotype, Emma Caroline Materne

Honors Theses

Polymerase Chain Reaction (PCR) typically employs the Taq or Klentaq1 DNA polymerase from Thermus aquaticus to elongate short sequences of DNA during DNA amplification. Both Taq and Klentaq1 retain activity at room temperature. During assembly of PCR at room temperature, the activity of Taq and Klentaq1 can result in spurious products due to elongation of primers bound to non-target sequences. A mutation of isoleucine to leucine at position 707 of Klentaq1 results in slowing of the enzyme at room temperature without compromising the fidelity of the enzyme. To understand how a mutation over 20Å from the active site can affect …

One-Pot Heteroconjugate Addition-Diels-Alder Reactions And Acetate-Catalyzed Aldol Reactions Of Α-Silyl Nitriles, Carly Mueller

Honors Theses

1. A one-pot three-step Diels–Alder reaction sequence of ethyl propiolate and thiols can be performed to produce high yields of complex bicyclic products. A KOt-Bu-catalyzed thioconjugate addition of thiols to enoates, oxidation of the generated thioenoate by mCPBA, and Li-catalyzed Diels–Alder addition of cyclopentadiene occur in situ, without any purification of intermediates.
2. Stereoselectivity of the Diels–Alder product was examined by utilizing a chiral sulfone substrate. It was determined that these substrates were unable to provide significant stereochemical control.
3. Silylation of 3-phenylpropionitrile is achieved at the α-position with trimethylsilyl trifluoromethanesulfonate and trialkylamine base. Catalyzed by tetrabutylammonium acetate (2.5 mol%), …

Do The Inter-Nucleotide Domain Loops Act As An Entropic Sink In The Catalytic Activity Of 3-Phosphoglycerate Dehydrogenase (3pgdh)?, Cristina Adelia Meeham

Honors Theses

In protein science the relationship between protein dynamics and catalytic activity are the subject of considerable contemporary interest. Although protein motions are frequently observed during ligand binding and release steps, the contribution of protein motions to the catalysis of bond making/breaking processes is more difficult to probe and verify. Currently, the field of protein science is trying to uncover the deeper role that dynamics plays in the catalytic activity and allosteric regulation of proteins and to better understand how to more effectively and efficiently target proteins in cancer therapeutics and other metabolic pathways.

Determination Of Trace Metals, Volatile Organic Compounds, And Other Water Standards In Wmu Drinking Water, Tyler Walter

Honors Theses

The USEPA creates drinking water maximum contamination levels to support safety in all environments. Inductively coupled plasma-optical emission spectroscopy (ICP-OES), Watersafe® Drinking Water Test kits, and solid phase microextraction with gas chromatography were used to assess the safety of drinking water in three buildings (Davis Hall, the Chemistry Building, and the Dalton Center) on the campus of Western Michigan University. ICP-OES was used to determine the concentration of several trace metals (Cu, Zn, Fe, Mn, Ni, Pb, and As), Watersafe® Drinking Water Test kits were used to determine the concentration of common contaminants and conditions (E. coli, pesticides atrazine and …

Roman Religion, Medicine, And Disease, Stephanie Clark

Honors Theses

Medicine, as experienced in the Roman Empire, was rapidly evolving. Balancing the newly developed theories with the already-established religious belief sparked the beginning of medical secularization. There were separate worlds, that of science and medicine, and that of the every day public, that had to be bridged in a way that honored both traditions, yet kept their integrity. The development of science and medicine pioneered by Galen, a philosopher whose medical knowledge and theory guided practitioners for almost two millennia, hit levels of exploration and understanding in ancient Rome that warranted its basis as common medical theory. However, the world, …

Adenovirus Type 5 Virions Asymmetrically Lose Icosahedral Structure At Low Phs Of Endosomes, Jennifer Marie Jarboe

Honors Theses

After receptor mediated endocytosis into an endosome, human Adenovirus Type 5 (Ad5) undergoes structural changes that allow the virus to release a viral protein, pVI, that lyses the endosome and releases the virus core into the cytosol, where it travels to the nucleus to insert its genome. Structural studies of Ad5 at a range of pHs typical of endosomes (7.5-4.5) using a transmission electron microscope show that Ad5 undergoes asymmetrical loss of proteins from vertex regions at the pH of the late endosome (pH5.15). Following further acidification, Ad5 ejects core material preferentially through one vertex—indicating an asymmetry at one vertex …

The Inner Workings Of The Dna Copying Nanomachine : Kinetic Studies Of Dna Polymerase I From The Thermophilic Bacterium Rhodothermus Marinus, Emily P. Kornberg

Honors Theses

DNA polymerase I from Rhodothermus marinus is a high-fidelity DNA polymerase capable of operating at high temperatures and incorporating 2´,3´-dideoxynucleotides. The R. marinus DNA Polymerase I active site contains an unusual proline in the middle of a mobile “O helix.” This proline residue is hypothesized to decrease the relative free energy of a kinetic checkpoint termed the ajar conformation, and thereby slow the incorporation of incorrect nucleotides. We aim to test the accuracy of a newly developed nucleotide incorporation model, in which the enzyme allows the template to interact with the bound dNTP in the ajar conformation, whether correct or …

Trimethylsilyl Trifluoromethanesulfonate-Mediated Additions To Acetals, Nitrones, And Aminals, Chelsea Safran

Honors Theses

One-pot reactions were studied in order to develop procedures for the formation of important carbon-carbon and carbon-nitrogen bonds that are easily reproducible. In the presence of trimethylsilyl triflouromethanesulfonate (TMSOTf), Mukaiyama-aldol and aldol-like reactions occur in one-pot due to TMSOTf acting as a Lewis acid and silylating agent. A variety of reactions, including methoxyalkylation, were performed to form carbon-nitrogen bonds. Here, research involving TMSOTf-mediated additions to acetals, nitrones, and aminals will be discussed.

Investigating The Effects Of Bag3 Knockdown On The Cytotoxicity Of The Anticancer Drug Laromustine, Kayla Gross

Honors Theses

Laromustine is a sulfonylhydrazine anticancer prodrug whose cytotoxicity results from the formation of interstrand cross-links caused by the synergistic action of co- generated 2-chloroethylating and carbamoylating species. The cytotoxic activities of Laromustine involve the induction of apoptosis. Described herein is an investigation into this drug’s effects on apoptotic gene expression in HL-60 cells using qRT-PCR. Significant changes in the expression levels of 13 genes were observed, most dramatically in the upregulation of the bcl2-associated athanogene 3 (BAG3) gene. Given the pro-survival role of BAG3 in the cell, this investigation sought to decrease BAG3 mRNA levels in HL-60 cells using transient …

Relationship Of Cross-Linking Potential To Mechanism Of Cell Death, Adam N. Spierer

Honors Theses

Mechlorethamine (HN2), a nitrogen derivative of mustard gas, was the first synthetic anti-tumor chemotherapeutic because it forms covalent cross-links between strands of duplex DNA. HN2 represents a class of bifunctional alkylating agents that are both chemotherapeutic and carcinogenic: diepoxybutane (DEB), the active form of the pro-drug treosulfan, and epichlorohydrin (ECH), a structural hybrid of HN2 and DEB, also form covalent cross-links between DNA. While HN2 and DEB are clinically used as anti-tumor chemotherapeutics, ECH is a structural hybrid of these two compounds not used in a clinical setting. Accordingly, we aimed to understand the relationship between the cross-linking potential of …

Exploring The Interaction Between Human Granulin-A (Hgrn-A) And Amyloid-Β (Aβ) Peptide, Michael Samel

Honors Theses

Alzheimer’s disease (AD) is the most common form of dementia affecting people over the age of 60, yet a detailed understanding of the molecular changes involved in AD remains a significant challenge to modern medicine. The hallmarks of an AD brain include the presence of senile plaques formed by a protein called amyloid-β (Aβ), along with inflammation of the brain. Aβ self-associates to form clumps of protein called “aggregates” which are known to be the primary toxic agents in AD pathology; however, several other proteins have also been implicated in this pathology. One such protein called progranulin (PGRN), which under …

The Relationship Between Live Coral And Macroalgae In South Caicos As Influenced By Herbivorous Fishes, Sarah Byce

Honors Theses

Marine life is the basis for most industries in the Turks and Caicos Islands, located on the outskirts of the Caribbean Sea. Few studies have been carried out to assess the current status of reefs in this region, especially those off the shore of South Caicos Island. The AGRRA v.4.0 methodologies were employed create baseline assessments of stony corals, macroalgae and associated fishes and to explore the relationships between these key reef organisms. This study was based on 10 different locations both inside and outside of Marine Protected Areas (MPAs) and including exposed and sheltered reefs in proximity to South …

Elucidation Of The Pax/Six Gene Regulatory Network In Ephydatia Muelleri, Anna Rued

Honors Theses

The evolution of gene regulatory networks accounts for much of the diversity we observe in the animal kingdom. In particular, the Pax/Six/Eya/Dac gene network has been known to play critical roles in development of all bilaterians and cnidarians. However, this network has not been characterized in Porifera. These studies focus on tracing the evolutionary history of the PSED network back to the most basal organism in the metazoan phylogeny through demonstrating the presence of a direct gene regulatory network between PaxB and Six1/2 orthologs in sponges. To this end, putatitve Six1/2 cis- regulatory elements were identified while the PaxBprd transcription …

Alteration In 5ht1a Receptor Activity From A Prenatal Exposure To Dexamethasone In A Stressed And Non-Stressed Adult Male Rat, Darshan S. Shah

Honors Theses

Synthetic glucocorticoids (GC) are used as a clinical therapeutic to stimulate lung development in fetuses that present the risk of preterm delivery. Previous studies have shown that a prenatal exposure to Dexamethasone (DEX) causes a disturbance in normal GC mediation of neuritic outgrowth, cell signaling, and serotonergic systems. Our hypothesis is that a prenatal exposure to DEX during the third trimester of pregnancy alters 5HT1A receptor function. Pregnant dams were injected daily with 150μg/ml/kg of DEX from gestation day 14 through 19. Control dams were treated with and equal volume of saline. Swim stress followed by elevated plus maze testing …