Biochemistry, Biophysics, and Structural Biology Commons^™

Cloning And Heterologous Expression Of Human Nachrs And A Unique Spider Venom Toxin, Christine M. Vega

Theses and Dissertations

Drug development research has long focused on synthesizing novel therapeutics while overlooking isolation from naturally available sources. Recently, the discovery of the therapeutic effects of highly bioavailable animal venom caused the field of venom research to soar in popularity. Animal venom serves as a natural, sophisticated tool optimized over millions of years by evolution with the ability to bind to ion channels such as nAChRs, non-specific ligand-gated ion channels distributed throughout the human nervous system, with high selectivity and specificity. However, purifying individual venom toxins from crude venom is challenging due to its availability. Therefore, synthesizing large quantities of venom …

Activity-Based Protein Profiling On Nucleophilic Amino Acid Residues With Pyrocarbonates, James Van Horn

Chemistry & Biochemistry Undergraduate Honors Theses

The complexity of the proteome requires strategies that efficiently characterize protein functions. Activity-Based Protein Profiling (ABPP) is a method that identifies enzyme activity by targeting key catalytic residues. This study focused on histidine, a residue involved in enzymatic catalysis, metal coordination, and protein-protein interactions. Despite its importance, histidine-specific chemical probes are limited due to its variable reactivity. This work developed and characterized a histidine-specific probe using a pyrocarbonate-based mechanism. Singleresidue assays confirmed selective reactivity of the probe with histidine over other nucleophilic amino acids. Further testing on enzymatic proteins and lysed cell proteomes showed that the probe modified histidine residues …

Eepd1 Evolved A Unique Dna Clamping Dimer Protecting Reversed Replication Forks, Runze Shen

Dissertations and Theses (Open Access)

Exonuclease/endonuclease/phosphatase (EEP)-fold hydrolases are canonically monomeric phosphodiesterases exemplified by APE1, DNase I, and TDP2 nucleases. While EEP superfamily domain-containing protein 1 (EEPD1) acts in DNA stress responses, its proposed nuclease activities are enigmatic. Here, we integrate hybrid structural methods, evolution, biochemistry, cancer genomics, molecular and cell biology to define EEPD1’s structure, assembly, and function at stalled DNA replication fork intermediates. Combined results show that EEPD1 surprisingly requires both the unique EEP domain dimer and distinctive tandem Helix-hairpin-Helix [(HhH)₂] domains to clamp double-stranded(ds) DNA at reversed DNA replication forks for fork protection. X-ray scattering, crystal, and cryo-EM structures unveil …

Impact Of Tumor Cell Expressed Cd38 On Metastasis And Immune Evasion In Breast Cancer, Tanvi Visal

Dissertations and Theses (Open Access)

Triple-negative breast cancer (TNBC) is a highly metastatic breast cancer subtype. The epithelial-to-mesenchymal transition (EMT) of cancer cells is a key feature of the metastatic cascade and is not a binary process but often generates malignant cells with both epithelial (E) and mesenchymal (M) traits known as hybrid EM cells. Recent studies highlight the enhanced metastatic potential of the hybrid EM cells. However, molecular insights and targetable vulnerabilities within hybrid EM remain elusive. We discovered that hybrid EM murine tumors are enriched in CD38, an immunesuppressive molecule associated with worse clinical outcomes in liquid malignancies but relatively understudied in solid …

The Extracellular Domains Of The Ampa, Kainate, And Orphan Delta Receptor Regulate Channel Gating In Distinct Ways, Cuauhtemoc Ulises Gonzalez

Dissertations and Theses (Open Access)

The ionotropic glutamate receptors are ligand-gated cationic channels essential for neuroplasticity and neurological functions such as learning, memory, behavior, cognition, and motor coordination. Mutations in these channels are linked to various disorders including autism, ataxia, and epilepsy, making them compelling pharmacological targets. Within this family, the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and kainate receptor mediate their function through fast glutamate-gated ionotropic activity, which needs precise structural changes to perform properly. While Cryo-EM structures have provided snap shots of these proteins, questions remain regarding the dynamics across conformations and individual roles of the extracellular amino-terminal and agonist binding domain in dictating function. …

Overcoming Resistance To Cdk4/6-Targeted Therapy Using Jak2/Stat3 Inhibitor In Triple-Negative Breast Cancer, Chuling Zhuang

Dissertations and Theses (Open Access)

Breast cancer is the most common type of cancer diagnosed in women, with nearly 30% of cases becoming metastatic accounting for over 90% of breast cancer-related deaths. Among different breast cancer subtypes, triple-negative breast cancer (TNBC) has the worst prognosis and the highest propensity to metastasize. However, TNBC patients have limited treatment options due to their lack of actionable drug targets while therapeutic resistances result in high rates of recurrence and metastasis. Cyclin-dependent kinase 4 and 6 (CDK4/6) are major cell cycle regulators that control G1 to S phase transition and aberrant hyperactivation of the CDK4/6 pathway results in uncontrolled …

Role Of Mir-4732-3p In Breast Cancer Brain Metastasis And Brain Metastatic Tumor Microenvironment, Munazza Samar Khan

Dissertations and Theses (Open Access)

In this study, we aimed to identify microRNAs (miRNAs) that may play important roles in breast cancer brain metastasis (BCBM). To this end, we conducted miRNA-sequencing of extracellular vesicles isolated from the serum samples of 6 BCBM patients and 8 Stage I/II/III breast cancer patients, and identified 49 circulating miRNAs that were upregulated in BCBM patients compared to Stage I/II/III breast cancer. Upon further analysis, we identified miR-4732-3p to be upregulated in brain-tropic triple-negative breast cancer (TNBC) cell lines, compared to parental lines. MiR-4732-3p overexpression increased metastatic properties of TNBC cells, including proliferation, migration, invasion, and maintenance of a mesenchymal …

Investigating Metabolic And Mitochondrial Adaptations Triggered By Blood Flow During The Endothelial-To-Hematopoietic Transition, Paulina Horton

Dissertations and Theses (Open Access)

Hematopoietic stem cell (HSC) transplant is the standard of care for many hematologic diseases. However, many patients cannot benefit from this potentially curative treatment because they cannot find a suitable donor, contributing to a high level of unmet need. Recently, bona fide HSCs capable of robust engraftment and differentiation have been generated from iPSCs utilizing wall shear stress (WSS) to help promote HSC generation. However, the mechanisms through which WSS regulates hematopoiesis remain poorly understood. Scientists, therefore, continue to look for the mechanotransduction pathways that promote hematopoiesis, and key answers may lie in examining the role of extrinsic factors that …

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 …

Structural Stability Of Fgf1-Fgf2 Dimer Established Via Salt Bridges With Mutation K296q, Ashleigh Letterman

Chemistry & Biochemistry Undergraduate Honors Theses

Fibroblast Growth Factors (FGFs) are a family of cell-signaling proteins. FGF, specifically the FGF-1 subfamily, which contains FGF-1 and FGF-2, is important in several biological functions such as wound healing, cell proliferation, and angiogenesis. FGF-1 has cell proliferation properties and FGF-2 has angiogenic properties. These FGFs have great potential for wound-healing therapy medications...

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Regulation Of Ccr7 Signaling Events By G-Protein-Coupled Receptor Kinases 2 And 3, Anahi Sanchez

Open Access Theses & Dissertations

G protein-coupled receptors (GPCR) can bind multiple ligands, leading to differential signaling events termed biased signaling. C-C chemokine receptor 7 (CCR7) is a GPCR known to have biased signaling between the two ligands it binds to, CCL19 and CCL21. Binding of C-C Chemokine Ligand 19 (CCL19) promotes a high level of CCR7 phosphorylation, while CCL21 leads to a much lower level of CCR7 phosphorylation; findings observed in HEK and dendritic cells. GPCR kinases (GRKs), which can control the phosphorylation patterns of a GPCR, are hypothesized to regulate biased signaling of a receptor. GRK expression differs between cell lines and cell …

Developing A Small Molecule To Inhibit Hsf1 Expression In Cancer And Evaluating Natural Genetic Variation In Small Molecule Toxicity., Michaela Kendal Foley

Theses and Dissertations

Each year cancer affects nearly 20 million people worldwide and genetic differences across populations can impact cancer onset and progression. Specifically, tumors with high levels of HSF1, the master regulator of the cytoprotective heat shock response (HSR), are correlated with poor patient outcomes in multiple cancers such as prostate, breast, and melanoma. Subsequently, the development of pharmacological inhibitors of HSF1 represents a promising strategy for anticancer therapeutics. Using a luciferase-based transcriptional reporter, two small molecule libraries were screened for inhibitors of HSF1 expression in human embryonic kidney cells, yielding ten compounds that decrease HSF1 expression. To identify if cancer lines …

Amyloid Aggregation And Mitigation, Zhenzhen Zhang

All Dissertations

The buildup of protein in tissues and organs plays a major role in unfunctional several serious diseases, including Alzheimer’s disease, Parkinson’s disease, and Type 2 diabetes, each tied to specific proteins that form harmful amyloid deposits. Amyloid aggregation typically follows a sigmoidal kinetic curve, beginning with a slow lag phase, followed by rapid fibril growth, and eventually reaching a plateau where mature, stable fibrils are formed. However, the early stage of aggregation remains particularly difficult to capture experimentally due to the highly dynamic nature and low abundance of small oligomeric species. In this dissertation, we employed discrete molecular dynamics (DMD) …

Development And Functional Characterization Of Carbon Nanodot-Peptide Conjugates For The Treatment Of Bone Disease, Abigail Ali

Honors Theses

Carbon nanodots (CDs) synthesized from carbon nanopowder under acid oxidative conditions have unique bone-bind properties that could be exploited for theranostic purposes. In the zebrafish vertebrate model system, CDs bind to bone with high affinity and specificity, they don’t appear to bind to other tissues and they do not affect the bone physiology or animal viability. Thus, carbon-derived CDs could be developed for the delivery of pharmacological agents to bones to treat diseases such as osteoporosis. Biologicals such as peptides, proteins and antibodies are a new and exciting class of pharmacological agents that have been successfully used in treating complex …

Biophysical Characterization Of Thermophilic Branched-Chain Amino Acid Periplasmic Binding Protein From Thermotoga Maritima, Sky Marsicano

Honors Theses

Members of the periplasmic binding protein superfamily are involved in the selective passage of ligands through bacterial cell membranes. The hyperthermophilic eubacterium Thermotoga maritima encodes a putative periplasmic branched chain amino acid binding protein (TM1135). The gene was cloned into pET21a(+), overexpressed in Escherichia coli, purified using Ni-NTA chromatography, and confirmed with SDS-PAGE and MALDI mass spectrometry. Biophysical characterization of the protein was performed with fluorescence spectroscopy, absorbance spectroscopy, and circular dichroism experiments to investigate structural stability and ligand binding ability. Using circular dichroism, we demonstrate that TM1135 binds to the branched chain amino acids isoleucine, leucine, and valine, and …

Isolation And Identification Of Active Antimicrobial Compounds In Alcaligenes And Chromobacterium Strains, Hannah Lwin

Honors Theses

ESKAPE pathogens comprise six bacteria that can be highly virulent and are likely to develop antibiotic resistance to many of the currently available antibiotics. New antibiotics are needed to combat these pathogens. Our approach was to isolate and identify antimicrobial compounds from bacteria isolated from soil. Two isolates demonstrating antimicrobial activity were identified as Chromobacterium sp. and Alcaligenes parafaecalis. Preliminary extraction of their antimicrobials was performed.

Fouling-Resistant Voltammetric Xylazine Sensors For Detection Of The Street Drug “Tranq”, Ann Holland Wemple

Honors Theses

As the opioid crisis continues to wreak havoc on a national and global scale, it is increasingly critical to develop methodologies to detect the most dangerous of these drugs as fentanyl and its derivatives have orders of magnitude higher potency than morphine. Recently, the scientific challenge for chemical detection of fentanyl and its derivatives has been complicated by both the constantly increasing synthetic variations of the drug as well as the expanded use of adulterants. One tragically consequential example is the nocuous street drug known as “Tranq” which combines fentanyl or a fentanyl derivative with the veterinary sedative Rompun®, chemically …

Implications Of Acetylation And Phosphorylation On Metabolic Enzymes, Nour Fatema

Graduate Theses and Dissertations

All living things depend on glycolysis and the TCA cycle for energy production and metabolic control. Post-translational modifications (PTMs) such as acetylation and phosphorylation, which can change enzyme activity, substrate binding, and overall metabolic balance, tightly regulate these pathways. Diseases like cancer and metabolic problems are associated with disruptions in these alterations.

Serine phosphorylation and lysine acetylation are two of the many PTMs that are evolutionarily conserved processes that alter protein function. Previously thought to be a static histone alteration, acetylation is now understood to be a dynamic regulator of metabolic enzymes that modifies contacts, charge, and conformation. In response …

Evolutionarily Conserved Functions Of The Gene Frazzled In Midline Axon Guidance In Drosophila Melanogaster And Tribolium Castaneum., Piyasi Ghosh

Graduate Theses and Dissertations

Axon guidance in bilaterians is often controlled by various signaling pathways in the nervous system, which determine the fate of the axons if they cross the midline or not. One such pathway involved is the ligand-receptor pair Netrin (Net) and Frazzled (Fra), which is also known as the attractive pathway that promotes midline crossing axons in insects and other bilaterians. Orthologs of the pathway ligand Netrins and their receptors Frazzled [Fra] in insects and Deleted in Colorectal cancer [DCC] in vertebrates are widely conserved in bilaterians. How well these regulatory roles of the protein are conserved is poorly understood. In …

Bacterial Chondronecrosis With Osteomyelitis In Broiler Chickens: Experimental Lameness And Additive Probiotic Treatments, Amanda Anthney

Graduate Theses and Dissertations

With the global population already surpassing 8.2 billion and expected to reach 9.7 billion by 2050, the poultry industry has seen a surge in demand due to its unmatched efficiency and affordability for consumers across the globe. Selective breeding and quality nutrition developments since the industry's commercialization have allowed producers to grow broilers up to 7 pounds by market age. While this extraordinarily efficient process has allowed quality poultry products to be available worldwide, the modern-day broiler has developed a multitude of musculoskeletal issues. Due to the lack of integral skeletal development to match the rapid production of muscle tissue, …

Dna Gyrase Inhibition By Ni(Ii)-Schiff Base Complexes Via In Silico Molecular Docking Studies: Spectroscopic, Dft Calculations And In Vitro Pharmacological Assessment, Ikechukwu P. Ejidike, Amani Direm, Cemal Parlak, Solomon A. Olaleru, Charles O. Adetunji, Athar Ata, Et. Al.

Michigan Tech Publications

The current world's life-threatening illnesses have amplified multidrug resistance infections, bringing about immune system mayhem, thus, the quest for novel antimicrobial compounds with a broad spectrum of action. Four Ni(II) complexes, [Ni(YB)Cl]·2H₂O (C1), [Ni(YB)Br]·H₂O (C2), [Ni(YB)NO₃]·3H₂O (C3), [Ni(YB)COOCH₃]·2H₂O (C4) [HYB = 4-[(1E)-N-{2-[(Z)-(4-methoxybenzylidene)amino]ethyl}ethanimidoyl]benzene-1,3-diol], were synthesized. Analytical techniques like CHNS analysis, UV–Vis, FT-IR, molar conductance, XRD, ¹H NMR, and TGA/DTA were utilized for characterization. The calculated …

A Qualitative Nmr And Histological Analysis Of Adipocere Formation In Different Aqueous Environments Using Sus Scrofa Models, Mia M. Sorrentino

Student Theses

Adipocere is a wax-like crust that has the potential to form over corpses in moist, humid, and anaerobic environments, preserving them in a process similar to that of mummification. The substance can be identified within 3-6 months postmortem and is characterized by the ratio of saturated fatty acids to unsaturated fatty acids. Palmitic acid and stearic acid are the most abundant in comparison to myristic and oleic acids. The goal of this study was to investigate factors affecting adipocere formation in different aqueous environments. Pork belly samples were submerged in water samples collected from different places around New York City …

Characterization Of 3d Printed Microdialysis Probes For Solute Recovery And Non-Specific Adsorption, Bailey N. Scoggins

Chemistry & Biochemistry Undergraduate Honors Theses

Microdialysis is an important sampling technique that has uses in a wide range of disciplines, such as neuroscience and pharmacokinetics. 3D printing aims to address adaptability and customization issues that are present in standard “off-the-shelf” microdialysis probes. This work aims to lay the groundwork for characterizing a 3D printed microdialysis probe designed at the University of Arkansas. One experiment involved measuring solute recovery of caffeine as a function of flow rate of a standard CMA 11 probe to assess its membrane performance. The other goal was to learn about non-specific adsorption tendencies of enzymes (i.e., to what degree proteins stick …

Intratumoral Fibrin As A Novel Immunomodulatory Factor In Pancreatic Ductal Adenocarcinoma, Mazharul Karim

Open Access Theses & Dissertations

In-situ coagulation is a common clinical feature of pancreatic ductal adenocarcinoma (PDAC) that presents a highly thrombotic and crosslinked insoluble fibrin (x-fibrin)-laden tumor stroma (FibTS). However, the specific impact of FibTS on immune cells behavior remains largely unexplored in this poorly infiltrated tumor. We aimed to elucidate how FibTS in PDAC regulates immune cell infiltration, polarization, and crosstalk that favors immunosuppressive microenvironment and tumor growth. We characterized human PDAC tissues by multiplex immunostaining and checked the spatial distribution of immune cells based on the presence of x-fibrin. We investigated how FibTS influences the infiltration of tumor-associated macrophage (TAM) and T-cell …

Multiscale Integration Of Receptor-Ligand Dynamics Into Discrete And Continuous Tumor Growth Models With Application To Tyrosine Kinase Inhibitor Treatment, Romasa Qasim

Open Access Theses & Dissertations

The epidermal growth factor (EGF) receptor cascade plays a crucial role in the survival and proliferation of tumor cells. Tyrosine kinase inhibitors (TKIs) are a class of drugs that inhibit epidermal growth factor receptors (EGFRs), thereby preventing the downstream signal transduction. Despite their importance, models that link spatial receptor dynamics to tumor growth remain scarce. Further, TKIs act through selective mechanisms, inhibiting active, inactive, or all receptor states, which poses a challenge to traditional modeling approaches.

We propose to numerically study two mathematical models incorporating receptor-dynamics into cancer models to describe the impact of EGFR overexpression and TKIs. The first …

Jak1 V658f Drives Oncogenic Transformation Via Transcriptional Reprogramming Independent Of Y598 Phosphorylation And Canonical Jak-Stat Signaling, Omar Javier Rodriguez Moncivais

Open Access Theses & Dissertations

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive and complex malignancy that accounts for 15% of pediatric acute lymphoblastic leukemia (ALL) cases in the United States. Tyrosine kinases control critical cellular processes, including the development, survival, and activation of T cells, and are established drivers of leukemia.Tyrosine kinases involved in hematological disorders include receptor tyrosine kinases and non-receptor tyrosine kinases family members such as SRC, ABL, FAK, and Janus kinases (JAKs). This study primarily focused on JAK1 gain-of-function (GoF) mutations. These mutations are recognized as hyperactivating mutations, maintaining kinase activity of JAKs on and essentially keeping downstream signaling effectors, like …

Intraspecific Genetic Variation In Green Salamanders (Aneides Aeneus) At Bays Mountain Park, Brianna Drake

Electronic Theses and Dissertations

Accurate taxonomy is crucial for conserving vulnerable cryptic species like the green salamander (Aneides aeneus) in the Southern Appalachian Mountains. Prior studies identified three distinct lineages within the A. aeneus complex: Northern Appalachians, Southern Appalachians, and Blue-Ridge Escarpment. One previously collected sample indicated green salamanders in northeast Tennessee fit within the Northern lineage. The present study uses molecular data of A. aeneus at Bays Mountain Park (BMP) in Kingsport, Tennessee, to determine where the BMP population fits within these lineages. It was hypothesized that individuals from BMP belong in the northern lineage. Tail tips were collected from thirty-four …

Investigating The Effect Of Fasting On Senescent Cells In Nothobranchius Furzeri Fish, Israel A. Akinola

Electronic Theses and Dissertations

Senescent cells (SCs) have been documented to accumulate with age in the organism. Recent studies have shown that reducing the number of SCs in an organism result in tissue rejuvenation and extension of life expectancy. Intermittent fasting is reported to have multiple health benefits and is speculated to reduce the burden of SCs. Nothobranchius furzeri are a new model organism for studying aging and for which there are short- and long-lived strains available. We hypothesize that long- and short-lived strains of N. furzeri will accumulate SCs at different rates; and that fasting will reduce the burden of SCs.

The results …

Structure Disorder And Magnetic Behavior Of An Olivine-Type Cathode Material, Hamida Hassan, Madalynn Marshall

Symposium of Student Scholars

Our research investigates the structure disorder and magnetic behavior of Li(Mn,Fe)PO₄, an olivine-type material relevant for lithium-ion battery applications. Using single-crystal neutron diffraction at Oak Ridge National Laboratory, we precisely determined Mn and Fe occupancy, revealing a 56% Fe and 44% Mn distribution at the atomic 4c site within the Pnma space group. Additionally, we observed significant lithium site vacancies (78% occupied), influencing the material's electrochemical and magnetic properties. The varying Mn/Fe ratio affected spin reorientation transitions, shifting from antiferromagnetic alignment along the a-axis to the b-axis. Our findings provide crucial insights for optimizing olivine-based cathodes, enhancing energy …

Assessing The Behavioral Impact Of Pyridostigmine Bromide In Rats, Noah A. Martin

Honors Theses

Pyridostigmine bromide (PB) is an organophosphate (OP) nerve agent prophylactic used to protect warfighters against chemical warfare agents. OPs inhibit the neural enzyme acetylcholinesterase (AChE) in the brain. This leads to the buildup of acetylcholine, causing respiratory failure, seizures, and death. PB functions by inhibiting ~30% of peripheral AChE temporarily, protecting the enzymes so that the body is able to restore sufficient cholinergic function post-exposure. PB does not cross the blood-brain barrier, though it may still indirectly affect toxicity in the brain due to repeated AChE inhibition throughout treatment, or by inhibition of non-target ChE’s in the blood. The aim …