Biochemistry Commons^™

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, …

Structural Characterization Of Peptide Nanoaggregates At Varying Concentrations And Their Impact On Cellular Responses, Malika Rozmetova

Theses and Dissertations

Peptide nano-assemblies can regulate cellular pathways in a structure-dependent manner. Here, we show that the enzyme-responsive peptide NapFFK(NBD)Yp forms distinct nanoscale assemblies at different concentrations, triggering differential ER stress and extracellular vesicle release in MDA-MB231 cells. These results highlight the importance of supramolecular organization in peptide–cell interactions.

Absolute Quantification And Identification Of Rna From Rna-Lipid Nanoparticles Using High Resolution Mass Spectrometry, Jason C. Funderburk

Theses and Dissertations

RNA therapeutics are a rising drug category with potential use for a range of conditions encompassing infectious diseases to therapies for cancer, diseases, and genetic disorders. RNA-lipid nanoparticles (RNA-LNPs) are the prominent delivery method for these therapeutics approved products include mRNA vaccines and polyneuropathy treatments. The emergency use authorizations and orphan drug status of current RNA-LNP drugs has allowed approval without finalization of the regulatory analytical procedures for quality monitoring. The objective of the study was to develop an LC-MS assay to simultaneously measure identity and concentration of two therapeutically relevant intact RNA constructs extracted from RNA-LNPs to enhance quality …

Bacillus Subtilis: A Bacterium That Can Potentially Degrade Low-Density Polyethylene (Ldpe) And Polyethylene Terephthalate (Pet), Migdalia Flores

Theses and Dissertations

The widespread application and disposal of plastics, such as low-density polyethylene (LDPE) and polyethylene terephthalate (PET), have raised significant environmental health concerns. Because of each plastic’s stability and durability, these plastics exhibit limited natural degradation in the environment. Recently, the environmentally friendly biodegradation of plastics by living microorganisms has attracted more attention, as they can assist in the natural degradation process. In this study, the bacterial strain Bacillus subtilis ATCC6051 was used to degrade LDPE and PET for 60 days. To measure the degradation of low-density (LDPE) and polyethylene terephthalate (PET), the dry weight was taken, and physical characteristics were …

3d Bioprinting On Electrospun Nanofibrous Scaffolds To Fabricate Myocardial Patches, Muthu Parkkavi S

Theses and Dissertations

Tissue-engineered three-dimensional (3D) myocardial patches offer superior and innovative treatment strategy for myocardial infarction (MI). Among the various scaffold fabrication techniques, electrospinning and 3D bioprinting have received great attention due to their ability to recreate native cardiac tissue mimetic characteristics. Despite several advantages, electrospun nanofibers have limitations in cell delivery due to random cell seeding, while bioprinting faces challenges in creating hydrogel constructs with ideal mechanical properties capable of supporting cardiac contraction/relaxation cycle. Hence in this work, hybrid myocardial patches were developed by converging electrospinning and bioprinting techniques.

Electrospinning of PLCL:PEOz (B73, 7:3 blend of poly-L-lactide-co-ε-caprolactone (PLCL) and polyethyl oxazoline …

Acute Exposure Of American Oyster (Crassostrea Virginica) To Selected Antidepressant Drug: Histological, Biochemical, And Immunohistochemical Assessments, Md. Faisal Amin

Theses and Dissertations

The rapid increase in pharmaceutical use has brought significant health benefits to humans. Studies have shown that many pharmaceuticals, such as antidepressants, are often detected in surface waters, groundwater, and even drinking water. These pharmaceuticals in aquatic environments threaten marine life seriously. Marine bivalves are vital source of seafood for people worldwide. In this study, we examined the effects of short-term exposure to fluoxetine, an antidepressant used to treat depression, at low (0.5 μg/L) and high (5 μg/L) doses over a one-week period on American oysters (Crassostrea virginica) under controlled laboratory conditions. Histological analysis revealed atrophy in the gills and …

Analyzing How Taste And Nutrition Impact Learning And Memory In Honey Bees Through Olfactory Associative Conditioning, Alessandra Elizabeth Perry

Theses and Dissertations

Honey bees detect sweet nectar, but not all sweet-tasting sugars provide nutrition. Unlike fruit flies, which can learn to avoid non-nutritious sweet foods, bees may lack this ability. To test if bees form caloric frustration memory (CFM), we conditioned them using odors paired with L-glucose (sweet but non-nutritious) or D-glucose (sweet and nutritious). Bees rewarded with L-glucose showed lower learning and long-term memory compared to D-glucose. Bees cannot differentiate between an odor associated with rewards containing malaise-causing compounds and an odor associated with a reward alone during differential conditioning. Therefore, we used differential conditioning to determine if lower acquisition in …

Cytidine Triphosphate Specifically Modulates Parb-Mediated Dna Compaction: Insights From Single-Molecule Analysis And Parb C-Terminal Lysine Mutagenesis, Lois Akosua Serwaa

Theses and Dissertations

ParB is a central player in bacterial chromosome segregation, and cytidine triphosphate (CTP) is known to modulate its DNA compaction activity. This study explored whether CTP’s regulatory effect is due to specific molecular interactions beyond its known CTP-binding pocket. Using single-molecule flow-stretching and TIRF microscopy, we showed that CTP significantly reduces DNA compaction by wild-type Bacillus subtilis ParB, while ATP has no effect, supporting the hypothesis that CTP acts through specific recognition rather than general charge. CTP’s modulatory effect persisted across C-terminal domain (CTD) lysine mutants. Compaction was reduced in wild-type and K255A but abolished in K252A and K259A. The …

Oxytocin As A Possible Vegf Inhibitor For Treatment Of Diabetic Retinopathy, Daira Yepez

Theses and Dissertations

Diabetic retinopathy (DR) is a major complication of diabetes and a leading cause of vision loss largely driven by the overexpression of vascular endothelial growth factor (VEGF), which promotes neovascularization and vascular permeability in the retina. Current treatments, primarily anti-VEGF injections, inhibit the effects of VEGF once it has been secreted but can be ineffective in a certain subset of patients. Recent studies suggest that oxytocin (OXT), a neuropeptide mainly known for its roles in reproduction and social bonding, may downregulate VEGF expression. This study aimed to investigate whether OXT influences VEGF secretion in the human retinal pigment epithelial (RPE) …

Investigating The Role Of Metallothioneins In Fungal Iron Homeostasis, David Eap

Theses and Dissertations

The pathogenic fungi Aspergillus fumigatus requires metals to survive and infect humans, but metal overload can be detrimental. Metallothioneins (MTs) are small, cysteine-rich proteins that alleviate metal toxicity by binding excess metals (typically Zn or Cu) for storage or delivery. A recent report indicates that the Fe-S cluster binding glutaredoxin GrxD and the putative Cu-MT CmtA were interacting under high iron conditions in A. fumigatus. We hypothesize that this MT may have a role in binding iron or Fe-S clusters under iron overload conditions to prevent iron toxicity. We also aim to characterize this new MT by determining its …

The Effects Of Ataxin-1 Overexpression In The Central Nervous System On Specific Behavioral And Physiological Characteristics Of Drosophila Melanogaster, Sydney Davis

Theses and Dissertations

Spinocerebellar ataxia type 1 (SCA1) is a dominantly inherited neurodegenerative disease caused by a CAG repeat expansion in the ataxin-1 gene, which results in an abnormally long polyglutamine tract. Similarly, overexpression of wildtype Ataxin-1 (wt-Atx-1) in Drosophila melanogaster leads to neurodegeneration, reduced lifespan, and impaired negative geotaxis. Observations include disruptions in sleep-wake cycles, increased oxidative stress biomarkers (like protein carbonyls), and dysregulation of developmental genes such as armadillo (arm) and nemo kinase (nmo). Additionally, elevated expression of SUMOylation-related genes (Aos-1, Uba2, and dSmt3 or dSumo) and increased SUMO protein levels indicate enhanced SUMOylation in the brain. Quantitative analysis of neuronal …

Exploring Sexual Dimorphism In A Drosophila Melanogaster Model Of Spinocerebellar Ataxia Type 1, Madelyn Hunter

Theses and Dissertations

Neurodegenerative diseases affect over 36 million people and are characterized by loss of motor control, neuronal degradation, and behavioral changes. The most common of these diseases exhibit sexually dimorphic effects. In this study, Spinocerebellar ataxia type 1 (SCA1) was modeled in the Drosophila central nervous system using the yeast hybrid UAS/GAL4 system. Locomotor activity and clock gene expression was monitored for male and female SCA1 and control flies. Clock genes such as per, tim, Clk, and cyc were monitored over a 24-hour period using qRT-PCR, and distinct sexual dimorphism was detected in locomotor activity and in gene expression for SCA1 …

Identification Of Cadmium As A Structural And Functional Modulator Of Psd-95 Regulating Nmdars At Postsynaptic Membranes, Claudia Garza

Theses and Dissertations

Postsynaptic density-95 (PSD-95) is an essential scaffolding protein in excitatory neurons. PSD-95’s N-terminal palmitoylation region elicits synaptic plasticity by targeting, anchoring, and trafficking glutamate receptors, such as N-methyl-d-aspartate receptors (NMDAR), to the postsynaptic membrane. The molecular interactions of PSD-95 and its dysregulation in excitatory synapses are currently being explored as primary causes of neurodegenerative diseases and disorders, such as Alzheimer’s disease, Schizophrenia, and Parkinson’s disease. Recent studies demonstrate an overaccumulation of zinc at two cysteines (C3 and C5) and two histidines (H24 and H28) of PSD-95 blocks palmitoylation, causing a loss of NMDAR at the postsynaptic membrane. In addition, exposure …

Transcription Factor Y- Box Binding Protein 1 (Ybx1) Enhances Sorafenib Resistance And Tumorigenic Capacities In Hepatocellular Carcinoma (Hcc), Dennis Kwabiah

Theses and Dissertations

Hepatocellular carcinoma (HCC) is the most common liver cancer, with early-stage cases potentially benefiting from surgical treatments like liver transplantation and hepatectomy. However, advanced HCC stages have poor prognosis due to resistance to therapies, especially sorafenib, a tyrosine kinase inhibitor approved for late-stage HCC. Despite its clinical use, sorafenib has limited efficacy in prolonging survival, and the mechanisms of resistance remain unclear. Analysis of The Cancer Genome Atlas (TCGA) HCC dataset shows elevated Y-box binding protein 1 (YBX1) expression in HCC tumors compared to normal liver tissues. Previous studies have indicated that YBX1 is involved in drug resistance in various …

Inhibition Of Lysine Deacetylase Activity Impacts Formation Of The Vitamin D Receptor Activation Complex, Shannon Dwyer

Theses and Dissertations

The vitamin D endocrine system is responsible for the regulation of many biological processes including bone metabolism, calcium homeostasis, cell proliferation and cell differentiation. Alterations to the vitamin D signaling pathway are associated with several diseases including bone diseases, diabetes, cardiovascular diseases, autoimmune diseases, and cancer. Vitamin D precursors are chemically modified to become the biologically active hormone, calcitriol. Calcitriol binds to the vitamin D receptor (VDR), a member of the nuclear hormone receptor (NHR) superfamily. VDR forms a heterodimer with retinoid X receptor (RXR) and together they bind to promoters containing vitamin D response elements (VDREs) to activate transcription …

Protein-Metal Interactions Of A-Synuclein And Bioactive Transition Metals Via Molecular Dynamics, Gonzalo R. Vazquez

Theses and Dissertations

Parkinson’s Disease (PD) is a neurodegenerative movement disorder which has been found to target the dopaminergic neurons of the substantia nigra. It is characterized by the formation of masses known as Lewy Bodies, formed by aggregates of the intrinsically disordered protein (IDP) -synuclein (asyn). Research suggests that alpha synuclein can undergo aggregation in the presence of heavy metals, which may accumulate in the body through a variety of mechanisms. To study how metals may play a role in wildtype (WT) asyn aggregation, MD simulation of the protein was performed in the presence of bioactive transition metals including Fe2+, Fe3+, Cu+, …

Biological And Chemical Evaluation Of Amide-Based Cjoc42 Derivatives As Potential Gankyrin-Inhibitors For The Treatment Of Breast, Lung, And Liver Cancer, Benita Britton-George

Theses and Dissertations

Gankyrin is an ankyrin-repeat protein overexpressed in certain cancers and is responsible for cell growth and proliferation. Gankyrin is important to the development of many types of cancer, including breast, lung, and liver cancer. Consequently, gankyrin and its various protein-protein interactions, are prospective therapeutic targets for inhibiting the progression of certain cancers. In 2016, the first small molecule inhibitor of gankyrin, cjoc42, was discovered and subsequently demonstrated modest antiproliferative activity against liver cancer cells. Previous work from our lab demonstrated that replacing the sulfonate ester of cjoc42 with an amide group significantly improved gankyrin binding while enhancing antiproliferative activity against …

Targeting Als: A Multi-Cellular Study On The Potential Therapeutic Role Of Azole-Based Compounds, Alisha R. Kennedy

Theses and Dissertations

Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig’s disease, is a progressive neurodegenerative disorder that leads to the degeneration of motor neurons, which control voluntary muscle movements such as eating, speaking, and breathing. As these neurons are damaged, voluntary movement ceases, leading to a fatal outcome. The survival time of ALS patients varies, ranging from a few months to up to 10 years. Chapter 1 of this thesis provides an overview of ALS, highlighting the role of transactive response DNA-binding protein 43 (TDP-43), a key feature in ALS and other neurodegenerative diseases. The aggregation of TDP-43, particularly due to …

Site-Specific Modification Of Antibodies Utilizing Microbial Transglutaminase For Improved Immunoassay Performance, Emily Beitello

Theses and Dissertations

Immobilization strategies used for fixing antibodies to solid phase surfaces significantly contribute to the antigen capture capacity and influences the performance and sensitivity of immunoassays. Traditional methodologies result in the random orientation and/or the weak attachment of immobilized antibodies. Different formats of immunoassays scope in applicability to many fields of research and everyday use. Improving the efficiency of immobilizing antibodies in immunoassays is a beneficial endeavor to increase assay sensitivity. Here, we investigated the use of enzyme-mediated conjugation of antibodies to facilitate a highly oriented immobilization. Microbial transglutaminase (mTG) catalyzes the covalent bond formation between a plethora of primary amine …

The Bacteriostatic, Regenerative, And Immunomodulatory Properties Of Extracellular Matrix Particles For Lung Injury, Keera P. Rhoads

Theses and Dissertations

Acute respiratory distress syndrome (ARDS) is a prevalent, life-threatening lung condition, affecting nearly 200,000 Americans annually, with a 40% international mortality rate. There is no cure for ARDS, and current pharmacological treatments have limited effectiveness. Symptoms can be mitigated with mechanical ventilation, though this often leads to ventilator-induced lung injuries (VILI) and puts critically ill patients at risk of infections, including ventilator-associated pneumonia (VAP). A promising therapeutic is the extracellular matrix (ECM), a complex network of structural proteins and bioactive molecules that has been shown to have anti-inflammatory properties and prevent fibrosis. We aim to utilize the regenerative and immunomodulatory …

Unleashing Serine Palmitoyltransferase In Test Tubes And Mice, Matthew W. Peart

Theses and Dissertations

Canonically known both for structural contributions to lipid bilayers and roles in cell signaling, the sphingolipids comprise a dynamic, multifaceted class of molecules which are studied to understand homeostatic cell biology as well as pathophysiology. Sphingolipids contribute to tissue-specific structures such as myelin, a multilayer membrane that allows for rapid conduction of action potentials along neuronal axons. All sphingolipids are downstream products of the rate-limiting and initiating enzyme in the de novo sphingolipid synthesis pathway, Serine palmitoyltransferase (SPT). Demonstrative of its status as the enzyme that catalyzes a crucial step in a biochemical pathway, SPT activity is strictly regulated. This …

Tc-Ptp-Mediated Regulation Of P38 Mapk Pathway Promotes Uvb-Induced Apoptosis In Skin, Lindsey Susie Shim

Theses and Dissertations

T-cell protein tyrosine phosphatase (TC-PTP) is a non-receptor PTP that has been shown to have various roles in signaling pathways. Our previous studies have demonstrated that the TC-PTP deficiency in the epidermis can exacerbate hyperplastic response by inducing epidermal cell proliferation in response to tumor promoter TPA or UVB exposure. This implies that TC-PTP plays a tumor-suppressive role in the epidermis and provides protection against UVB radiation, which is well known to contribute to skin cancer development. The p38 mitogen-activated protein kinase (MAPK) is one of serine/threonine kinases that are activated through environmental stress including UVB. It has been demonstrated …

Effect Of An Anti-Hiv Polymer Based Nanoformulation On Immune Mediating Cells Within The Gut Associated Lymphoid Tissue And Its Behavioural Impacts, Blessed Ofori

Theses and Dissertations

This thesis investigates the therapeutic potential of nanoformulated antiretroviral therapy (NF cART) and its implications for HIV-associated chronic inflammation and neurobehavioral outcomes. In the first study, NF cART demonstrated enhanced efficacy in modulating inflammasome activation and reducing viral reservoirs in gut-associated lymphoid tissue (GALT) and the small intestine of HIV-infected humanized mice. Key markers of inflammation (NLRP3, Caspase-1, and IL-1β) and viral replication (LTR and p24 levels) were significantly suppressed with NF cART compared to conventional therapy, though residual LTR expression persisted in the small intestine. In the second study, nanoformulated Emtricitabine uniquely enhanced locomotor activity and reduced anxiety-like behaviors …

Developing Coexpression Systems To Introduce Hydroxyproline Into Protein Engineered Collagen Peptides Utilizing Hydroxylase From Acanthamoeba Polyphaga Mimivirus, Jennifer Soldatich

Theses and Dissertations

A major challenge of developing collagen mimetic peptides (CMPs) by bacterial expression is to include hydroxyproline for biomedical applications. Coexpression of Prolyl-4-hydroxylase from A.mimivirus with CMPs was investigated. Additionally, four expression designs were created for potential applications in mammalian cells to utilize their natural ability of proline-hydroxylation by post-translational modification.

Informatics-Based Discovery Of New Natural Products, Their Biosynthesis, And Their Biological Roles, Ethan Older

Theses and Dissertations

In this work, genome mining and biosynthetic knowledge are applied for the discovery of new natural products, their biosynthetic pathways, and their promising biological activities and roles through the development of two unique new informatics-based approaches.

In chapter one, an overview of microbial natural product biological functions and biosynthesis is provided. The use of bioinformatics leveraging microbial natural product biosynthetic knowledge is also introduced. This chapter highlights the importance and need for developing innovative approaches to accessing microbial natural products, a vastly untapped source of new molecules with promising biological activities.

In chapter two, a correlational network linking the gene-encoded …

Quantification Of Immunometabolite Derived Protein Modifications During Mitochondrial Metabolic Stress, Justin Hunter Cox

Theses and Dissertations

The immunometabolite itaconate accumulates during lipopolysaccharide (LPS) stimulation of macrophages and microglia. Itaconate non-enzymatically reacts with cysteine residues to generate 2,3-dicarboxypropylcysteine (2,3-DCP), referred to as protein dicarboxypropylation. The tricarboxylic acid (TCA) cycle metabolite fumarate non-enzymatically reacts with the amino acid cysteine to form S-(2-succino)-cysteine (2SC), resulting in irreversible protein succination. Since fumarate and itaconate levels dynamically change in activated immune cells, the levels of both 2SC and 2,3-DCP reflect the abundance of these metabolites and their capacity to modify protein structure and function. I generated esters of 2SC and 2,3-DCP from protein hydrolysates and used stable isotope dilution liquid chromatography-tandem …

Design Of An Artificial Transcription Factor For Inducing Potent Interferon-Γ Signals, Ashley King

Theses and Dissertations

Cytokines are small immune signaling proteins responsible for cellular communication and their levels are tightly regulated throughout immune recognition and defense. Interferon gamma is a key cytokine responsible for upregulation of antigen presentation and supports the differentiation of pro-inflammatory effector cells. Due to its role in regulation, excess interferon gamma is cleared from the body limiting the success of interferon gamma immunotherapies. This study reports the design and validation of an artificial transcription factor (ATF) that induces endogenous interferon gamma expression. The transcription factor contains zinc finger proteins to recognize the interferon gamma gene and an activation domain to promote …

Characterizing The Role Of The Escherchia Coli Monothiol Glutaredoxin, Grxd, As An Iron-Sulfur Cluster Carrier Protein, Claire Elizabeth Fisher

Theses and Dissertations

Iron-sulfur (Fe-S) clusters are important cofactors with a primary role of electron transport that are required by proteins involved in wide range of biological pathways such as respiration, photosynthesis, and DNA repair. In Escherichia coli (E. coli), the assembly and transfer of these clusters to their target apo-protein is a highly coordinated process encoded by the multiprotein systems iscRSUAhscBAfdx and sufABCDSE operons. These clusters are assembled on a scaffold protein, where they are then transferred to a carrier protein that will deliver the cluster to the target apo-protein. The Isc and Suf systems contain their own carrier proteins IscA …

Assessment Of Tripeptides Self-Assembly & Er Stress On Cell Viability And Exosome Secretion In Mda-Mb231, Azmat Parveen

Theses and Dissertations

This study delves into the effects of tripeptides KYpF and WYpK(NBD) on MDA-MB-231 cells, uncovering KYpF's ability to reduce cell proliferation and exosome secretion in peptide treated cells. Conversely, WYpK(NBD) demonstrated significant toxicity at 10 μM. These insights pave the way for optimizing peptide-based cellular treatments for exosome secretion purposes.