Biochemistry, Biophysics, and Structural Biology Commons^™

31p Solution Nmr Investigation Of Abasic Dna, Clarissa R. Krimmel

Graduate Theses/Dissertations

Base excision repair (BER) mechanisms fix single base lesions in DNA, such as T:G mismatches. During the base excision repair mechanism, an abasic site (AP site) is formed as an intermediate. AP sites are unstable and highly mutagenic; they can stop DNA replication. This research investigates how the conformational properties of abasic sites in DNA affect the binding recognition of enzymes involved in DNA repair mechanisms, including BER. Three different abasic sequences are being analyzed for this research project. A second project looks at the effects of a naturally occurring purine derivative, hypoxanthine, on the DNA backbone. These hypoxanthine lesions …

The Geminivirus Al2 Protein Interacts With Host Proteins Involved In The Plant Antiviral Response, Pheobean Atieno Odongo

Graduate Research Theses & Dissertations

Geminiviruses are economically important plant DNA viruses infecting a broad range of plant species and causing devastating crop diseases, resulting in up to 100% crop loss. As a result of these heavy losses on food and cash crops, these viruses represent a new threat to global food security and sustainability. In this research, I use Tomato golden mosaic virus (TGMV) to study host-virus relationships with an overall goal of developing sustainable and eco-friendly crop resistance. TGMV belongs to the Geminivirus subgroup, Begomovirus, that is characterized by a split genome consisting of two single-stranded circular DNAs. The TGMV genome encodes proteins …

Preliminary Analysis Of Soil Volatile Organic Compounds As Soil Health Indicators, Thorne Taul

Graduate Theses, Dissertations, and Problem Reports (ETD)

Over the past decade, soil health (SH) has gained popularity due to the novelty of sustainable soil use related to human wellbeing. Soil health describes the overall quality of soil and its capacity to function over time. As interest in SH grows, researchers continue to explore new soil health indicators that can improve knowledge on how soil health is assessed and managed. Some indicators directly reflect soil health status, and some indirectly relate to processes and functions occurring within the soil. Volatile organic compounds (VOCs) are naturally occurring compounds that play a role in multiple soil processes. They are associated …

Role Of The Osaa Transcription Factor Gene In Development, Secondary Metabolism And Virulence In The Mycotoxigenic Fungus Aspergillus Flavus, Farzana Ehetasum Hossain

Graduate Research Theses & Dissertations

Aspergillus flavus colonizes oil-seed crops, contaminating them with aflatoxins; highly carcinogenic mycotoxins that cause severe health and economic losses. Genetic studies may reveal new targets for effective control strategies. Here, we characterized a putative WOPR transcription factor gene, osaA, in A. flavus. Our results revealed that osaA regulates conidiation and sclerotial formation. Importantly, deletion of osaA reduces aflatoxin B1 production, while, unexpectedly, transcriptome analysis indicated upregulation of aflatoxin biosynthetic genes, suggesting post-transcriptional or cofactor-mediated regulation. Cyclopiazonic acid production also decreased in the absence of osaA. In addition, the osaA mutant exhibited upregulation of genes in the imizoquin and aspirochlorine clusters. …

Interaction Of The Dap-10 Fluorescent Light-Up Aptamer With An Environment-Sensitive Dye, Crystal Violet, Marina Tsukanova

Honors Undergraduate Theses

Crystal violet (CV) is an environment-sensitive dye whose fluorescence is strongly influenced by microenvironment polarity and viscosity, increasing markedly when rotational and vibrational motions are restricted. While the fluorescence enhancement of CV by fluorescent light-up aptamers (FLAPs) has been noted in literature, the specific binding interactions between CV and aptamers in the DAP-10 family have remained under-investigated.  The objective of this work is to elucidate the binding site interactions between CV and the DAP-10-42 FLAP. It is hypothesized that positions 34 and 35 of the aptamer’s sequence reside in a proposed quadruplex-duplex junction that form the dye-binding pocket of DAP-10 …

Development Of A Split Deoxyribozyme-Based Assay For Detecting Hepatitis B Virus, Dalila Zovko

Honors Undergraduate Theses

Rapid, accessible nucleic acid-based detection methods are needed for hepatitis B virus (HBV). A split deoxyribozyme assay was developed for sequence-specific fluorescence detection. The assay was evaluated using synthetic target and plasmid-derived material. The assay showed target-dependent fluorescence and low-concentration linear range with a LOD of 1.9 nM. The assay supports detection and semi-quantification of HBV genetic material as shown using plasmid-derived transcript samples from HBV genotypes B, C, and D. The selected target corresponded to nt 363–406 of the HBV genome and was chosen based on sequence alignment showing conservation across most genotypes. Genotype-specific detection remains a future application …

Dna Half-Adder Based Calculator Driven By 4j Molecular Switches, Andrea Gissele Canizalez Covaleda

Honors Undergraduate Theses

DNA nanostructures have computing functions due to the predictable base pairing of nucleic acids (Watson–Crick). This property allows the programming of DNA circuits that integrate DNA logic gates capable of recognizing oligonucleotides. This molecular device offers the advantages of biocompatibility and potential applications in personalized medicine for diagnosis and therapies.

Our lab has developed DNA logic gates formed by the connection of YES strands via DNA four-way junctions (4J), which can function as molecular switches to develop a DNA-based calculator. Our DNA half-adder calculator nanostructure is designed to recognize up to three combinations of DNA inputs using three DNA strands …

Exploring Anticholinergic Neurotoxicity: Diphenhydramine's Impact On Neuro-2a Cell Morphology, Expression, And Viability, Jordan B. Mcintyre

Honors Undergraduate Theses

Anticholinergic medications, such as diphenhydramine (commonly known as Benadryl), are increasingly recognized for their association with cognitive impairment and neurodegenerative disease. These medications, which inhibit the action of acetylcholine, a neurotransmitter essential for the formation and utilization of the central and peripheral nervous system, have been implicated in conditions such as dementia and may impact fundamental cellular processes like neurogenesis and cell proliferation. This study investigates the effects of diphenhydramine on neurogenesis when introduced to Neuro-2a cells during differentiation. For all studies cells were plated on coverslips or in 6-well plates with differentiation media containing 0 ng/mL, 50 ng/mL, …

Channel-Opening Kinetics Of Complex Kainate Receptors, Noah S. Saunders

Electronic Theses & Dissertations (2024 - present)

Ionotropic glutamate receptors (iGluRs) are found both pre- and postsynaptically in neuronal membranes, and mediate the majority of fast excitatory synaptic transmission in response to the binding of glutamate, a major excitatory neurotransmitter in the central nervous system (CNS). Ionotropic glutamate receptors are divided into three distinct subtypes: kainate, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), and N-methyl-D-aspartic acid (NMDA) receptors. Auxiliary proteins specific to each receptor subtype also play a role in tuning both receptor expression and gating properties, such as neuropilin and tolloid-like (NETO) proteins that modulate kainate receptors, and transmembrane AMPA receptor regulatory proteins (TARPs) that regulate AMPA receptors. Like …

The Biosynthesis Of The Natural Product N-Nitroglycine, Gabriel Padilla

Graduate Studies Theses and Dissertations 2026

N-Nitroglycine (NNG) is a nitramine [R(R′)N–NO2; R′=H or alkyl] natural product (NP) produced by certain actinomycetes, such as Streptomyces noursei. At the beginning of this project, the biosynthesis of this NP was unknown. The goal was to determine how NNG and its nitramine moiety are enzymatically formed. This could lead to the discovery of novel nitramine NPs with diverse applications as well as alternative/green synthesis of nitramine explosives. This work begins by examining diverse biochemical N–N bond formation strategies. Nitrogen cycle enzymes, nitration of NPs, kutzneride biosynthesis, the aspartate/nitrosuccinate superfamily, hydrazinoacetic acid (HAA) biosynthesis, and streptozocin biosynthesis are among the …

Evaluating Novel Targeted Combination Therapies For Gastrointestinal Cancers, Joseph A. Goode

Graduate Studies Theses and Dissertations 2026

Gastrointestinal (GI) cancers remain among the leading causes of cancer-related mortality worldwide, with therapeutic resistance continuing to limit the effectiveness of current treatments. Three complementary studies were conducted to identify therapeutic vulnerabilities and evaluate novel combination strategies in pancreatic ductal adenocarcinoma (PDAC) and colorectal cancer (CRC).  First, dual inhibition of fibroblast growth factor receptor 4 (FGFR4) and phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling was investigated in PDAC models. A combination of targeted drug treatments reduced viability, clonogenic survival, migration, and suppressed signaling pathways involved in translational control. This supported a functional interaction between FGFR4 and PI3K-mTOR co-activation in …

Methylseleninic Acid Transformations In Nutrient Rich Water Containing Algae Exposed To Simulated Sunlight, Mikayla Cormier

Theses and Dissertations (Comprehensive)

Methylseleninic acid (MSA(IV)) is an organic form of selenium that has been suggested to be one of the most bioaccumulative forms of selenium in aquatic ecosystems. However, there have been no lab studies that confirm this, which is the reason this study was conducted. Once MSA(IV) and other bioavailable forms of selenium enter aquatic ecosystems, organisms such as algae take up these compounds which then bioaccumulate through the food chain. S. obliquus was exposed to 10 ppb MSA(IV) in 10% Bold’s basal medium (BBM) in a growth chamber to mimic environmental conditions over a 7-day period. Carbon traps and filters …

Analysis Of Alternative Oxidase In Non-Angiosperm Plants, Anissa M. Francis

Theses and Dissertations (Comprehensive)

Alternative oxidase (AOX) is a mitochondrial terminal oxidase that provides an alternative pathway for electron transport, allowing plants to maintain respiratory flexibility under environmental stress conditions. While AOX has been extensively studied in angiosperms (flowering plants), little is known about its distribution and conservation in non-angiosperms. Based on gaps identified in the literature, this thesis investigated the distribution of AOX across non-angiosperm plant lineages. Although AOX is present in many green algae and is therefore considered to be an ancient protein that originated before the existence of non-angiosperm plants, it remains unclear whether the protein is uniformly distributed across these …

The Importance Of The Proline Residue In The Ldiapa Motif Of Cholera Toxin, Akash Bharathan

Honors Undergraduate Theses

Cholera is currently on its seventh global pandemic, disproportionately affecting developing countries. Vibrio cholerae, the bacterial etiologic agent, is able to cause infection by adhering to intestinal epithelial cells and secreting cholera toxin (CT), an AB-type exotoxin that dysregulates signaling pathways. Previous research by the Teter lab has shown that Hsp90, a host cytosolic chaperone, is required for CT to enter the cytosol where it produces toxic effects. Hsp90 binds to CT at two specific motifs, RPPDEI and LDIAPA. The prolines in the RPPDEI motif are essential for binding, but the proline in the LDIAPA has yet to be …

Targeted And Screening Based Approaches To Analyze Drm Transcriptional Repressor Complex Activity In Caenorhabditis Elegans, Emily Washeleski

Dissertations, Master's Theses and Master's Reports

The molecular machinery that control the eukaryotic cell cycle, specifically the processes that mediate the switch between cellular division or quiescence, are essential for cellular and organismal viability. However, how the same machinery integrates with developmental or differentiation programs is less well understood. In Caenorhabditis elegans, the 8-subunit DRM complex (for Dp, Rb and MuvB), whose subunits belong to the Synthetic Mulitivulva (SynMuv) B class genes, is a central regulator of the cell cycle but also prevents inappropriate cell fate specification. The conserved mammalian DREAM complex (for Dp, Rb, E2F, And MuvB) is best known as a transcriptional repressor …

Physicochemical Characterization Of Small Extracellular Vesicles: Effects Of Immobilization, Isolation, And Disease State, Bianca M. Mercado Velez

Dissertations, Master's Theses and Master's Reports

Cancer treatments and survival outcomes have improved significantly in the last couple of decades, with survival rates increasing in the U.S. Despite improvements in treatment outcomes, early detection and treatment are crucial for improving cancer prognosis and survival rates. The standard cancer diagnostic procedure of tissue biopsy is highly invasive, leading to the further spread of cancer in some cases. Alternatively, the extraction of biofluids from cancer patients, also called a liquid biopsy, is increasingly popular because it is less invasive and more representative of the tumor microenvironment, which contains cancer cells, tumor genetic material, and extracellular vesicles, including small …

Exploring Fructose Mimetics As Chemotherapeutic Potentiators: Impact On Glut5-Mediated Cancer Cell Vulnerability, Vedant Buwa

Dissertations, Master's Theses and Master's Reports

Metabolic reprogramming toward increased sugar uptake is a hallmark of cancer, and fructose-specific uptake through the facilitative transporter GLUT5 is selectively upregulated in several adenocarcinomas, including breast and lung cancer. This dissertation develops and characterizes a panel of fluorescent fructose mimetics – the coumarin-based ManCou probes and the quinolinone-based ManQuin probes – as GLUT5-targeted reporters, cytotoxic effectors, and chemosensitization adjuvants, and establishes the boundaries within which each role holds.

The central experimental strategy pairs each GLUT5-targeted glycoconjugate with its sugar-free aglycone control, isolating transporter-mediated cytotoxicity from cytotoxicity intrinsic to the fluorophore itself. In luminal (MCF7) and triple-negative (MDA-MB-231) breast carcinoma, …

Entropic Forces Near Fluctuating Surfaces, Rubayet Hassan

Dissertations

Nanoscale structures are inherently dynamic due to persistent thermal fluctuations. Even in solid materials, these random deformations, driven by ambient thermal energy, can become significant when their characteristic scale approaches that of the structure itself and strongly influence their overall mechanical behavior. Examples of such structures include crystalline membranes, appearing in diverse forms such as nanotubes, nanoribbons, and kirigami/origami structures. Similarly, biological nanostructures, including lipid membranes, microtubules, actin filaments, and DNA, exhibit extreme flexibility and responsiveness due to their low bending rigidity. Numerous physiological processes are intrinsically linked to these thermal fluctuations, including exocytosis and endocytosis, membrane fusion, pore formation, …

Understanding The Fidelity And Specificity Of Dna Polymerase I, Bill R. Miller Iii, Andrew V. Yeager, Jake A. Collins, Alexis Blake, Elise Tate, Carol A. Parish, Eugene Y. Wu

Chemistry Faculty Publications

High-fidelity DNA polymerases employ complex mechanisms to catalyze template-dependent DNA synthesis while quickly discarding mismatches. Atomic-level structural details about short-lived states during nucleotide discrimination are necessary to gain insight into the kinetic checkpoints that contribute to fidelity. We performed microsecond molecular dynamics simulations of DNA polymerase I, large fragment, from Bacillus stearothermophilus (Bacillus fragment, or BF) in complex with a template guanine and a mismatched thymidine triphosphate to observe the early events in the process of selection against a mismatch. Although the nucleobases formed a wobble base pair early, the mismatched pair was blocked from fully entering the active site …

Potency Dependent Angiogenic Effect Of Bellis Perennis On In Ovo Chick Chorioallantoic Membrane Assay, Jayanthdevan V, Winston Vargheese V, Anish Fathima K, Lohita S

Indian Journal of Research in Homoeopathy

Background: Hormesis is the biological response of an organism for a particular dosage of a substance. The lower dose stimulates and higher dose inhibits. J Compton Burnett, an eminent homeopath, prescribed Bellis perennis for breast and uterine tumours, which suggests it could be due to the antiangiogenic property or angiogenic inhibiting property and clinically also it is used for healing of fractured bone and wound healing which may be due to angiogenic promoting property. This experiment deals with the dose dependent effect of Bellis perennis on In Ovo Chick Chorioallantoic Membrane Assay. Objective: To evaluate the Hormesis effect of Bellis …