Biochemistry Commons^™

Optimizing Expression Conditions For The Overexpression Of Iron Regulatory Protein Bol2 From C. Glabrata, Jade Ikahihifo-Bender, Dr. Caryn Outten, Mrs. Evan Talib

Caravel Undergraduate Research Journal

Due to its unique ability to serve as both an electron donor and acceptor, iron is utilized as a co-factor for many biological processes, including electron transfer, oxygen binding, and vitamin synthesis. Iron is also a key factor during fungal infections as the human host and invading pathogens battle over limited iron pools. The primary iron-responsive transcription factor Aft1 in the opportunistic pathogenic yeast Candida glabrata responds to iron deficiency by activating expression of iron acquisition genes. However, the mechanisms for sensing intracellular iron levels and regulating Aft1 activity in response to iron are unknown. The C. glabrata iron regulation …

The Universe Under A Microscope, Claire Chabot

Caravel Undergraduate Research Journal

No abstract provided.

Discovering The Southern Appalachian Grassy Balds, Nicholas Lenze

Caravel Undergraduate Research Journal

Grassy balds are unique Appalachian wonders, open meadows in the mountains where, ecologically, there should be trees. It has been hypothesized that some of the balds originated more than ten thousand years ago and were kept open by the grazing of large herbivores such as the mastodon and the wooly mammoth. Over the course of earth’s history, environmental and anthropogenic factors have shaped, modified and maintained the balds. Up to one hundred grassy balds were once recognized to exist in the southern Appalachians, but fewer exist today due to forest succession (Gersmehl, 1970). Collectively, the grassy balds share a common …

Understanding The Role Of Toxs As A Bile Sensing Component Of The Toxrs Virulence Regulatory System In Vibrio Spp., Minje Kim

Dartmouth College Ph.D Dissertations

Pathogenic Vibrio bacteria, such as V. cholerae and V. parahaemolyticus, colonize in the human small intestine to cause severe gastrointestinal disease. During the infection, these bacteria encounter bile salts, antimicrobial cholesterol metabolites secreted into the intestine. Pathogenic Vibrio species have evolved to utilize bile salts as signals to regulate virulence. The signaling depends in part on ToxRS, a conserved co-component transmembrane transcription regulator. ToxRS consists of the transcription factor ToxR and its membrane-tethered binding partner ToxS. ToxS is required for ToxR stability and full transcriptional activity. Although bile salts are known to influence ToxRS-dependent virulence gene expression, the molecular …

Shark Immunology And Its Biomedical Potential: Evolution, Innovation, And The Imperative Of Conservation, Reesha Bhagat

Undergraduate Honors Thesis Collection

This review aims to shed light on a significant ecological deficit and its implications for the future of science and medicine. Sharks possess a uniquely adaptive, cancer-resistant, and evolutionarily refined immune system with transformative biomedical potential, making their conservation a scientific and medical imperative. We are losing something medically irreplaceable, and we don’t even fully understand it yet. Shark conservation is a pressing scientific imperative because sharks are ecologically essential and represent an irreplaceable biomedical resource.

Sequence Determinants Of Rna G-Quadruplex Unfolding By Arg-Rich Regions, Naiduwadura Ivon Upekala De Silva, Puspa Kunwar, Md Ibnul Rifat Rahman, Joanna Koryo Kwao, Nathan Lehman, Zihan Zhang, Trenton Paul, Claire Cheng, Nicholas Truex, Hui-Ting Lee, Jun Zhang

Faculty Publications

RNA sequences with the potential to form G-quadruplexes (rGQs) are widespread but largely unfolded in cells by unknown mechanisms. rGQ folding status is a critical regulator of RNA splicing and translation. We show that rGQs can be unfolded by SR proteins, SR-related proteins, and other Arg-rich proteins, including SRSF1, SRSF3, SRSF9, U1-70K, and U2AF1. The length and composition of Arg-rich regions are key determinants of this activity: Arg residues are the primary drivers, while acidic residues attenuate the unfolding activity. To unfold ARPC2 rGQ, at least 13 Arg residues are required. Our findings identify Arg-rich proteins as previously unrecognized, helicase-independent …

Evaluation Of Flt3 Inhibition With Quizartinib During Busulfan Conditioning For Hematopoietic Stem Cell Transplantation, Catherine Jankovic

Biochemistry and Molecular Biology

Hematopoietic stem cell transplantation (HSCT) is one of the only curative therapy options for many hematologic malignancies. HSCT relies on effective conditioning regimens to deplete host hematopoietic cells and enable donor engraftment. The alkylating agent Busulfan is widely used in myeloablative conditioning strategies due to its potent cytotoxic effects on hematopoietic cells and ability to clear the bone marrow. However, optimization of conditioning strategies remains an important area of investigation to improve transplant outcomes and reduce toxicity. Preliminary studies have shown that the FLT3 inhibitor Quizartinib synergizes with some chemotherapeutic agents, suggesting that targeted inhibitors may enhance conventional conditioning regimens. …

Mechanisms Of Bacterial Glucokinase Inactivation Through Site-Specific Lysine Modification And Chemical Inhibition, Joseph Robert Will Andrews

Graduate Theses and Dissertations

Glycolysis and related metabolic pathways are controlled by various post-translational modifications (PTMs) that affect enzyme activity and metabolic flow. In E. coli, glucokinase (GLK) sits at the crossroads of glycolysis and the pentose phosphate pathway and carries out the first committed step of glycolysis: ATP-dependent phosphorylation of glucose. While it's known that glucose binding causes GLK to close its domains, how phosphate binding, lysine modification, and small-molecule inhibitors regulate GLK's shape and function is still not fully understood. Here, I combine structural biochemistry and enzymology to figure out how phosphate binding, specific mutations, and chemical inhibitors affect E. coli GLK. …

Dried Water Treatment Residuals Might Be An Option To Reduce Soluble Reactive Phosphorus Release From Soils, Katie B. Mckay

Biological and Agricultural Engineering Undergraduate Honors Theses

Nonpoint source pollution from agricultural landscapes contributes to freshwater eutrophication, with legacy phosphorus (P) in soils potentially driving soluble reactive phosphorus (SRP) losses to surface waters. The objectives of this study were to evaluate SRP adsorption by dried water treatment residuals (WTRs) produced by Beaver Water District, quantify reductions in soil SRP release across increasing WTR application rates, and compare dried WTR performance to prior WTR studies.

Dried WTRs (~98% solids) were assessed using batch sorption experiments and soil core incubations. Phosphorus sorption was measured by mixing WTRs with CaCl₂ solutions containing increasing SRP concentrations and fitting results to …

Acute Effects Of The Psychoactive Pollutant Fluoxetine On The Antipredator Behavior Of The Gulf Killifish (Fundulus Grandis), Semyra Reus

Honors Theses

Pharmaceutical contaminants are increasingly prevalent in aquatic environments, yet their sublethal effects on ecologically relevant behaviors remain poorly understood, particularly in estuarine systems. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, are of particular concern due to the conserved role of serotonin in regulating behavior across vertebrates. Here, we investigated how acute exposure to environmentally relevant concentrations of fluoxetine influences anti-predator behavior in Gulf killifish (Fundulus grandis), a key estuarine fish commonly found in saltmarsh habitats. Killifish were exposed to control (0 ng/L), low (17.8 ng/L), and high (596 ng/L) fluoxetine concentrations and subsequently tested in the presence …

Understanding Tlr3 Immune Response Activation In Cryptosporidium Parvum And Cryspovirus Pathogenesis, Surayya Hudayberganova

Biochemistry and Molecular Biology

Cryptosporidiosis is a serious gastrointestinal illness caused by a protozoan parasite known as Cryptosporidium. It is particularly dangerous for malnourished children and those with compromised immune systems. My research focuses on the Toll-like receptor 3 (TLR3) response to the Cryptosporidium parvum infection, specifically in the presence of the parasite’s viral mutualist named cryspovirus (CSpV1). Results using research methodologies like ELISA and RT-qPCR have indicated that TLR3 expression increases during the infection process of Cryptosporidium parvum (C. parvum). Furthermore, one intriguing observation concluded during this study suggests that administering the TLR3-specific inhibitor CU-CPT4a to infected cells drastically decreased this activation. This …

Ethanol State-Dependent Learning In The Honey Bee (Apis Mellifera), Ethan Neil Govea

Theses and Dissertations

Ethanol disrupts neural circuits involved in addiction and withdrawal, yet the molecular mechanisms underlying these effects remain poorly understood. One possibility is that ethanol alters an animal’s perceptual or internal state, causing a stimulus learned while intoxicated to be processed differently when the animal is sober. This study examined how ethanol exposure affects odor learning, recall, and discrimination in honey bees, a useful model because of their robust olfactory learning and experimentally accessible neural systems. Bees were differentially conditioned with appetitive reward (sucrose) during hexanol exposure and aversive stimulus (quinine) during decanol exposure. To assess olfactory processing and state dependency, …

Identification Of Peptides For A Muc13 Cancer Vaccine, Abigail Olivia Gomez

Theses and Dissertations

Mucin 13 (MUC13) is a transmembrane glycoprotein that is frequently overexpressed in epithelial cancers. Its extracellular domains and cytoplasmic signaling potential contribute to disrupted cell adhesion, increased invasion, and cancer-promoting pathways, making MUC13 a promising target for immunotherapy. This project used an in-silico approach to identify MUC13-derived peptides predicted to bind HLA class I molecules and support CD8+ T cell-mediated immune responses. Bioinformatics tools were used to screen candidate epitopes for HLA binding affinity, antigenicity, toxicity, IFN-γ-inducing potential, and population coverage, allowing rational prioritization of peptide candidates for experimentation. Selected peptides were evaluated in THP-1-derived macrophages using RT-PCR, Western blotting, …

Abnormal Trafficking And Processing Of Multiple Matrix Metalloproteinases Drive Cartilage Defects In Congenital Disorders Of Glycosylation, Chia-Lun Wu

All Dissertations

Congenital Disorders of Glycosylation (CDG) are rare metabolic diseases caused by defects in glycosylation. Despite identification of over 200 CDG types, the mechanisms linking glycosylation defects to diverse clinical phenotypes remain unclear. This dissertation uses zebrafish models of PMM2-CDG and STT3-CDG to redefine CDG pathogenesis, shifting from a simple glycan deficiency model to one involving disrupted cellular spatial organization.

We identify a protease-dependent pathway underlying craniofacial cartilage defects. Specifically, defective proteolytic processing of N-cadherin, a key adhesion molecule in chondrogenesis, is a central driver of pathology. We further uncover an unconventional trafficking mechanism in which ER stress and altered secretory …

A Novel Method Of Protein Purification Using Hedgehog Proteins As An Inducible, Self-Cleaving Tag, Antonia Kladias

Undergraduate Honors Theses

Because removing extraneous purification tag sequences from native proteins can be challenging and costly, there is demand for simple all-in-one techniques that directly furnish a tagless, functional protein-of-interest (POI). Current tagless purification systems are based on intein biochemistry; however, intein-based purification requires expensive, specialized resins and the POI often must be fused to the intein’s C-terminus. In this thesis, I present a novel approach for tagless POI purification in which the Drosophila melanogaster hedgehog protein catalytic domain (HhC) is repurposed as a small-molecule inducible, self-cleaving element dubbed Gtag. With Gtag, the POI is fused to the N-terminus of HhC/Gtag with …

Isolation, Purification, And Characterization Of Α-Galactosidase From Watermelon (Citrullus Lanatus), Christopher Henley Jr.

Chemistry & Biochemistry Undergraduate Honors Theses

The enzyme α-galactosidase is a type of glycosidase that removes galactose sugar units from larger molecules in cells. Compounds that inhibit glycosidases have been useful for understanding the structure and function of the enzymes they inhibit, and some have been used to treat certain diseases. Using inhibitors of α-galactosidase to study its characteristics and mechanisms may provide insights into its role in disease and its general utility. Advances in fields such as agriculture, sustainable fuels, and biomedicine may be facilitated by inhibition studies of α-galactosidase, but the current library of known inhibitors is relatively lacking. Obtaining α-galactosidase enzymes from chemical …

Mechanistic Insights Into Enterolactone-Mediated Glut4-Dependent Glucose Uptake, Merritt Smith

Senior Honors Theses

Type 2 diabetes mellitus (T2D) is one of the leading causes of morbidity and mortality in the United States, with approximately 25% of healthcare expenditures directed toward its management and associated metabolic complications. In response to the urgent need for novel therapeutic strategies, recent research has focused on bioactive compounds derived from dietary sources. In light of that, we identified the plant lignan matairesinol (MA) and its gut-derived metabolite, enterolactone (ENL), as agents capable of enhancing glucose uptake in 3T3-L1 differentiated adipocytes. These results suggest that enterolactone may represent a promising dietary supplement for improving glycemic control in patients with …

Cleft Palate And The Coordination Of Wnt Signaling And Pax9 In Murine Palatogenesis, Landon Wyatt

Honors Theses

Cleft palate is a common craniofacial birth defect that arises when the molecular and morphogenetic events guiding secondary palate formation lose coordination during a narrow developmental window. In mice, successful palatogenesis requires the paired palatal shelves to grow vertically, elevate above the tongue, and fuse at the midline; disruption of any of these steps can result in clefting. Two important regulators of this process are canonical Wnt signaling and the transcription factor Pax9, both of which contribute to normal palatal mesenchymal growth and patterning during early development. This paper first examines whether altered Dkk1/Wnt signaling contributes to the Pax9-null palate …

Analysis Of Bacterial Virulence And Resistance In A Model Of Recurrent Uti, Rachel L. Proper

Undergraduate Honors Theses

Urinary tract infection (UTI) is a major women’s health issue, affecting approximately 40% of women during their lifetime. Formation of a biofilm by UTI-causing bacteria poses a major challenge in treatment, as the protection provided by the biofilm hinders both host defenses and antibiotic treatment. Failure to eradicate these infections causes them to become recurrent (rUTI). Previous research indicates that rUTI may be comorbid with a mutation in the SERPINE1 gene, which causes fibrin to accumulate within the body. Literature also indicates that fibrin provides a better scaffold for bacterial attachment and, subsequently, biofilm formation. In this work it was …

Spin-Label Probing Of Gp28 Elucidates Interactions With Lipid Vesicles Using Cw-Epr, Maxwell Sutherland, Binaya Baral, Gary Lorigan

ONU Student Research Colloquium

The phage protein gp28 is a bacterial membrane lysis protein that functions outside of currently understood canonical pathways for bacterial lysis. Primarily, lysis is done in conjunction with proteins called spanins, however about 15% of gram negative bacteria infecting phages have coding for spanins. This led to the discovery of the disruptins, a class of non-spanin outer membrane disrupting proteins which includes gp28 from the φKT phage. To understand the mechanism in which gp28 disrupts the outer membrane, we employ spin labeling of the protein in its synthesis and create samples of artificial membranes. Using electron paramagnetic resonance (EPR), we …