Enzymes and Coenzymes Commons^™

Investigating Tau Pathology In The Retina And Anterior Segment Structures Of The Eye In A 3-Nitropropionic Acid–Induced Tauopathy Mouse Model, Mohamed Sayed Ahmed Abdel-Kader Qasem

Theses and Dissertations

Background and Objectives: Alzheimer's disease, the most prevalent neurodegenerative disorder in older adults, is characterized by accumulation of hyperphosphorylated tau and amyloid-beta (Aβ) plaques in the central nervous system. Given the retina's shared embryological origin with the brain, its direct neural connectivity via the optic nerve, and similarities in vasculature and age-related degeneration patterns, retinal pathology may serve as an early, non-invasive biomarker for Alzheimer's disease. This study employed 3-nitropropionic acid (3NP) as a pathway-specific tauopathy model driven by mitochondrial dysfunction. The study particularly aimed to investigate whether retinal and corneal tau pathology reflects underlying tau-related neurodegeneration triggered by …

Protein Allostery Probed By Ligands Across Sites, Virgil A. Woods

Dissertations, Theses, and Capstone Projects

Allostery is a pervasive regulatory principle throughout biology, yet the structural pathways by which distal inputs alter active‑site chemistry within protein structures remain incompletely defined and exploited. This dissertation uses protein tyrosine phosphatase 1B (PTP1B) as a tractable model to map those pathways with complementary experimental and computational tools. I integrate high‑resolution hydrogen-deuterium exchange mass spectrometry (HDX-MS), room-temperature crystallography, NMR, steady-state kinetics, crystallographic pseudo-ensembles, and machine-learning-guided ligand discovery. The working premise is that regulation reflects redistribution within a conformational ensemble rather than a binary switch. That orthogonal perturbations by small molecules, mutations, and protein partners can be used to both …

Computationally Assessing The Specificity Of Receptor Tyrosine Kinase Inhibitors, Htoo Say

Theses/Capstones/Creative Projects

Receptor tyrosine kinases (RTKs) are vital to cell signaling processes such as growth, survival, and differentiation. Dysregulation through mutation or overexpression often contributes to cancer, making RTKs key therapeutic targets for tyrosine kinase inhibitors (TKIs). However, the low specificity of many TKIs leads to off-target effects. This project uses molecular docking to evaluate the binding affinities and selectivity of FDA-approved TKIs across 18 RTK subtypes. The dockings conducted revealed significant variability in binding affinities, with Sorafenib exhibiting strong specificity for EphB2 (-7.6 kcal/mol) and poor compatibility with EphA7 and ErbB4 (-3.0 kcal/mol). These findings underscore the role of specific molecular …

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 …

Hdac5 Enzymatic Activity Regulates Scn4b Expression To Control Relapse-Like Cocaine Seeking, Daniel J. Wood

MUSC Theses and Dissertations

Substance Use Disorder (SUD) is a relapsing disorder characterized by repeated seeking and use of psychoactive substances despite negative consequences to the individual. Epigenetic changes within the medium spiny neurons (MSNs) of the nucleus accumbens (NAc) are thought to underly the lasting propensity to relapse in SUD. The epigenetic enzyme histone deacetylase 5 (HDAC5) in NAc MSNs limits the formation of reward-cue associations in rodent models of drug seeking, but not sucrose seeking, leading to decreased relapse-like behavior. However, whether HDAC5 reduces drug seeking behavior through its own deacetylase activity or through the recruitment of co-repressors is unknown. Furthermore, these …

Efficacy Of Collagenase Injection In Dupuytren’S Contracture, Janson Witcher

The PA Department Journal of Medical Science

Introduction: Dupuytren's contracture is a debilitating hand condition characterized by progressive contracture of the palmar fascia. The use of collagenase clostridium histolyticum injections has emerged as a minimally invasive alternative to surgical interventions, with varying degrees of efficacy and safety compared to traditional methods like limited fasciectomy and percutaneous needle fasciotomy.

Methods: A comprehensive literature review was conducted using PubMed to assess the efficacy and safety of collagenase injections for treating Dupuytren's contracture. The search focused on peer-reviewed randomized controlled trials, systematic reviews, and meta-analyses published in the last five years. Five relevant studies were selected based on the robustness …

Redox Control In A Fused Electron Transfer Flavoprotein From A Thermophilic Archaeon And Expanded Significance Of A Hydrogen Bond From A Conserved Histidine Residue That Contributes To Flavin Redox Tuning And Activation For Covalent Modification, Debarati Das

Theses and Dissertations--Chemistry

In absence of O₂ as terminal electron acceptors in anaerobic bacteria and archaea, carbohydrate metabolism is 15 times less efficient compared to aerobic energy metabolism resulting in energy deficit conditions. Despite their meager resources these anaerobes were able to generate H₂ and a chemiosmotic potential able to drive energy demanding reactions such as CO₂ or N₂ fixation. These observations raised concerns as production of high energy reductants (H₂) from mediocre fuels (NADH) defied the laws of thermodynamics.

In 2008, a known mechanism “electron bifurcation” but with flavins as redox mediators instead of quinones was …

Reversible Degradation Of Peptidoglycan By Lytic Transglycosylases, Aaron Devereaux

Theses and Dissertations (Comprehensive)

Antimicrobial resistance continues to be a burden on the global healthcare system with an estimated cost of billions of dollars and millions of deaths each year. Recently, there has been little to no development on new antibiotics to treat bacterial infection, and any that are developed become resisted to within a few years. Both Gram-positive and Gram-negative bacteria contain a mesh-like layer called peptidoglycan (PG) that surrounds their cells providing strength, cell shape, and protection from their environments. This layer is a polymer of N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) connected via a b-1,4-glycosidic bond, with each strand being cross-linked …

Identifying Notch-Regulated Genes Using A Specific Notch Signaling Inhibitor, Hammed Gafar

EWU Masters Thesis Collection

Bone remodeling is a dynamic process that requires a balance between bone resorption by osteoclasts and bone formation by osteoblasts to maintain skeletal integrity. Disruptions to this equilibrium can lead to pathological conditions such as osteoporosis. Osteoclasts originate from macrophages, and their differentiation is regulated by several signaling pathways, notably the notch signaling pathway. Gamma-secretase, an enzyme crucial for initiating notch signaling, can be inhibited by DAPT. However, DAPT also targets non-Notch substrates, complicating the identification of genes specifically regulated by Notch. To address this limitation, this study employed IMR-1A, a selective Notch pathway inhibitor that disrupts the assembly of …

Investigating The Production Challenges Of The P100.1 Phage Endolysin, Jonah O. Frago

EWU Masters Thesis Collection

Acne vulgaris is one of the most common skin diseases globally. One key aspect of acne pathogenesis is the disturbance of healthy strain diversity of the skin bacterium Cutibacterium acnes. Many acne treatments are antimicrobial; however, these treatments are generally nonspecific and carry a variety of side effects in addition to contributing to rising antibiotic resistance. Lytic bacteriophages (or phages) are viruses that infect and kill bacteria. Their lytic lifestyle is facilitated by enzymes called endolysins. Phages have been studied as an alternative to traditional antimicrobials in acne treatment and have shown reduced C. acnes load in acne lesions and …

5-Fluorouracil Induced Oxidative Stress Is Variable Across Triple Negative Breast Cancer Cell Lines, Rachel L. Walker

Departmental Honors & Graduate Capstone Projects

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with treatment limited to chemotherapy. However, not all patient tumors respond to chemotherapy. The variable cytotoxic effects of chemotherapies may be due to how cancer cells regulate reactive oxygen species (ROS). In this study, we examined two mouse breast cancer cell lines: 4T1 and EO771, vary when treated with hydrogen peroxide (H2O2) and 5-Fluorouracil (5FU), known ROS-inducing substances. In 4T1 cells H2O2 increased oxidized DNA but caused minimal cell death. While in EO771 cells that same amount of H2O2 caused complete apoptosis. Cell number, ROS, and cell death showed …

Magnetic Resonance Imaging Trackable Pathology-Triggered Polymersomes Toward Enzyme Replacement Theranostics For Gm1 Gangliosidosis, Dorian Foster

All Dissertations

This dissertation investigates the development and optimization of pathology-responsive polymersomes for simultaneous enhanced magnetic resonance imaging (MRI) and enzyme replacement therapy (ERT) in the treatment of GM1 gangliosidosis (GM1). While therapeutic strategies exist for similar, non-neuropathic lysosomal storage disorders, implementation towards GM1 faces significant challenges due to the blood-brain barrier.

Herein, we developed and characterized a range of low molecular weight hyaluronic acid-b-polylactic acid (HA-PLA) polymersomes (PSs) capable of encapsulating therapeutic enzymes in their hydrophilic core. These polymersomes exhibit pathophysiology-triggered responsiveness, degrading in the presence of acidic conditions, which is characteristic of lysosomes, and enzymes such as hexosaminidase A, which …

Fe(Iii) And Mn(Ii) Binding De Novo Designed Peptides And Their Oxidation With H2o2, Hannah Randall, Russ Upton

Honors Theses

Metalloenzymes perform a wide variety of reactions that are instrumental to the basic functions of life. Learning more about those enzymes–their structure, folding, active sites, and co-factors–can help to not only better understand the finer details of the chemical world, but also help provide answers and possible solutions to questions pertaining to alternative energy. Particulate Methane Monooxygenase (pMMO) is a metalloenzyme that oxidizes methane into methanol in the biological processes of some methanogenic bacteria, a valuable part of their process to obtain energy. One of its active sites, CuB, has a relatively unknown function. Heptad repeats of model enzymes have …

Targeting Coenzyme A Biosynthesis For Antifungal Development., Jessica Regan

Theses and Dissertations (ETD)

An estimated 1.5 million people die each year from invasive fungal infections (IFIs) involving dissemination to the deeper organs via the bloodstream, with estimated healthcare costs of over $7 billion in the U.S. alone. Collectively, several Candida species account for more than 75% of disseminated fungal infections in the U.S., with attributable mortality rates ranging 35-75%. Unfortunately, the prospect of curing these infections is limited by the modest efficacy of the available antifungal drugs: the azoles, echinocandins, and amphotericin B. Approximately one-third of patients with disseminated Candida infections are non-responsive to treatment with the azoles, and favorable response rates are …

Identification And Characterization Of Novel, Small Molecule Inhibitors Of Spermine Oxidase, Amelia Bryn Furbish

MUSC Theses and Dissertations

The major intracellular polyamines spermine and spermidine are abundant endogenous compounds that are essential for cellular growth and development. Dysregulation of polyamine metabolism has been implicated as a key mechanism of injury across multiple forms of clinically challenging pathologies. Of the enzymes within the polyamine pathway, the catabolic enzyme spermine oxidase (SMOX) is of particular interest as it is subject to induction in response to infection, neuronal excitotoxicity, ischemia, and oxidative stress. In addition to the loss of radical scavenging capabilities associated with spermine depletion, catabolism of spermine by SMOX results in the production of toxic byproducts, including H_{2 …}

Managing Stress: A Study Of Stress Response Mechanisms In Mycobacteria, Augusto C. Hunt Serracin

Biology Dissertations - Archive

Mycobacteria encompass many pathogenic species known to cause severe disease in humans. A well-known example is Mycobacterium tuberculosis (Mtb), the causative agent of the lung disease tuberculosis, which kills millions of humans worldwide yearly. Pathogenic mycobacteria like Mtb are challenging to treat because of their innate ability to adapt to environmental stress. Their unique cell physiology and conserved stress responses allow them to combat biological insults, regulate growth, and regulate genes involved in stress; all these responses increase tolerance to antibiotics. The current therapies to treat mycobacterial infections are lengthy and, at times, unsuccessful, partly due to antibiotic tolerance. A …

Nanodiscs: A Novel Approach To The Study Of The Methionine Abc Transporter System, Michael T. Winslow

Master's Theses

Membrane transporter proteins play the vital role of moving compounds in and out of the cell and are essential for all living organisms. ATP Binding Cassette (ABC) family transporters function both as importers and exporters in prokaryotes. MetNI is an E. coli Type I ABC transporter responsible for the uptake of methionine into the cytosol from the cell periplasmic space through the cell membrane to maintain intracellular methionine pools. ABC transporters, like other membrane proteins, are most often mechanistically and structurally studied in vitro, solubilized by detergents. However, detergent micelles may affect the conformational changes of membrane proteins relative to …

Comparison Of Hydrolysis Efficiency And Performance Of Four Recombinant Β- Glucuronidase Enzymes For The Detection Of Opioids In Urine Samples By Lc-Ms/Ms, Christina Fernandez

Student Theses

The United States has been experiencing a nationwide public health crisis since introducing prescription opioids in the 1990s. A central problem with opioids is their highly addictive nature causing a dose-dependent respiratory depression leading to overdoses and deaths. Drug overdose deaths have risen in the past two decades, with opioids being the dominant driver of this epidemic. Given the circumstances, accurate and efficient confirmatory analysis of opioids in urine is essential to monitoring patients’ compliance and preventing drug diversion in clinical and forensic settings. The development of recombinant β-glucuronidases allows for the hydrolysis of glucuronidated opioids using a shorter incubation …

The Impact Of Treatment With Palynziq® On Quality Of Life For Individuals With Pku, Teresa Heller

Dissertations and Theses (Open Access)

Management for phenylketonuria (PKU) has traditionally involved adhering to a strict low-protein diet to maintain phenylalanine (Phe) levels within the recommended range (μmol/L). The time commitment and financial, emotional, and social burdens of adhering to a restrictive diet, as well as the neurocognitive symptoms associated with elevated Phe levels, make it challenging to manage PKU and lead to reductions in quality of life. Palynziq^® is an enzyme substitution therapy used to lower blood Phe levels and liberate individuals with PKU from their restrictive diets. Previous studies have demonstrated the safety and efficacy of Palynziq^®, but our study …

Testing Of Indazole Inhibitors Of Kasa, A Vital Enzyme Of M. Tuberculosis, Karissa Highlander

Departmental Honors & Graduate Capstone Projects

Tuberculosis is a disease that affects the lungs caused by Mycobacterium tuberculosis (M. tuberculosis). Although drug treatment options exist, increased rates of antibiotic resistant strains have become more prevalent in recent years, driving a need for new treatment approaches. KasA, a β-ketoacyl synthase, has been found to synthesize parts of the cell wall and been identified as an attractive drug target. Previous medicinal chemistry research has been completed to synthesize six effective competitive inhibitors of KasA that would potentially block the enzyme from binding the substrate, preventing elongation of the backbone and creation of the mycolic fatty acids that …

Leveraging Bio-Inspired Molecules For Cancer Theranostics, Douglas S. Macpherson

Dissertations, Theses, and Capstone Projects

A variety of molecules can be radiolabeled and delivered to a cancer site for the purposes of diagnostics and therapy. Among the most promising of tumor targeting molecules are peptides and antibodies. These bio-inspired molecules can be designed and synthesized to target and respond to cancer cells based on the properties of those cells. Matrix metalloproteinase (MMP) enzymes are over-expressed by some metastatic cancers, in which they are responsible for the degradation and remodeling of the extracellular matrix. In recent years, MMPs have emerged as promising targets for enzyme-responsive diagnostic probes because oligopeptides can be designed to be selectively hydrolyzed …

The Effects Of Sex On Zebrafish Bone Metabolism, Simon Bagatto

Williams Honors College, Honors Research Projects

I investigated the effects of diet and sex on zebrafish bone metabolism. Zebrafish were subjected to either a high-calorie or low-calorie diet over a five-week period. After this diet, zebrafish scales were used to measure alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) enzyme activity with a fluorescent substrate. The enzyme activities were markers of the osteoblasts (ALP) and the osteoclasts (TRAP). These data were compared among sex and diet of the zebrafish using a repeated measures ANOVA statistical test. I also measured the number of resorption lacunae per scale (another indicator of osteoclast activity). The results showed higher TRAP …

Development Of A Chemical Biology Approach To Uncover The Influence Of Sequence Variations On Ces1 Activity In Live Cells, Samuel James Knebel

Masters Theses

Drug metabolism is the biochemical process of modifying drugs to detoxify and remove them through enzymatic transformations. These biotransformation’s occur primarily in the liver and are critical to understanding how pharmaceutical compounds are chemically altered inside the human body. Human carboxylesterases (CESs) catalyze the hydrolysis of esters, amides, thioesters, and carbamates. CES-mediated hydrolysis plays an important role in the metabolism of many drugs including the first FDA approved antiviral treatment for COVID-19, remdesivir (Veklury), the seizure control medication rufinamide (Banzel), and the flu antiviral drug oseltamivir (Tamiflu). CES activity is known to be influenced by a variety of factors including …

Production And Characterization Of A Phage Endolysin With Putative Antimicrobial Activity Against Cutibacterium Acnes, Kathryn M. Collins

EWU Masters Thesis Collection

Acne vulgaris (acne) is the eighth most common skin disorder worldwide. Because of the heterogeneous pathology of acne and the increasing antibiotic resistance of the causal agent (Cutibacterium acnes), novel therapeutics need to be developed to treat acne. One option is endolysins, highly conserved enzymes from bacteriophages that disrupt the bacterial cell wall. Endolysins retain bactericidal and bacteriostatic activity when applied to bacteria in vitro and are safe for topical application. We hypothesize that the endolysin (ENDL) from the P100.1 C. acnes bacteriophage will exhibit bacteriostatic activity against C. acnes in vitro. This study aims to bioinformatically characterize the P100.1 …

Structural And Inhibitory Studies On (I)Two Mycobacterium Tuberculosis Enzymes Essential For Capsular Glucan Biosynthesis And Mrna Degradation: (Ii) Hantann Virus L-Protein Endonuclease Domain, Hettiarachchige Thilina D. Jayasinghe

Theses & Dissertations

Mycobacterium tuberculosis (Mtb) is the pathogenic bacterium species that causes Tuberculosis (TB). Understanding the major biosynthetic pathways responsible for cell viability is essential in developing new drugs against Mtb. The first two projects will reflect our approach in identifying inhibitors against Mtb GlgE, Mtb GpsI, and characterization of protein inhibitor interactions using X-ray crystallography.

The enzyme GlgE plays an essential role in the α-glucan biosynthesis pathway in Mtb cells. These α-glucans are one of the major structural units in the Mtb capsule. GlgE catalyzes the elongation of α-glucan by transferring maltose from maltose-1-phosphate (M1P) to the non-reducing end …

Structural And Biochemical Studies Of Three Enzymes Involved In Amino Acid Metabolism To Develop Novel Drugs, Yahani Pankaja Jayasinghe Arachchige

Theses & Dissertations

Intrinsic drug resistance in bacteria predates the clinical use of antibiotics. Additionally, heterogeneous metabolic states and the ability of many bacteria to form biofilms further enhances bacterial survival during infection and exacerbates treatment challenges. This necessitates the identification of novel drugs against new drug targets. These studies focus on the development of compounds targeting enzymes in Mycobacterium tuberculosis (Mtb) and Staphylococcus aureus that avoid intrinsic antibiotic defenses. The Mtb-encoded homoserine transacetylase enzyme (HTA) catalyzes the first step of the methionine biosynthesis pathway that produces methionine and S-adenosyl methionine. These compounds are shown to be essential for both dormant …

Targeted Therpeutics For Prostate Cancer, Behind The Scenes Of Psma & Cysteine Protease Trapping Mechanism, Alireza Basiri

Theses & Dissertations

In an attempt to increase the residence time of PSMA-targeted theranostics inside the prostate cancer cells and tumors, we designed and prepared a CPTA-PSMATA resembling PSMA-617 by adding a well-known cysteine protease inhibitor (E-64) to the conjugate. Lysosomal proteases, including cysteine, serine, and aspartic families of hydrolytic enzymes, are expressed in high concentrations in the lysosomes and are responsible for the catabolism of proteins inside the cell [165, 278]. We proposed that after successful internalization of the PSMA-targeted conjugates into the cells, they will be conveyed to the endolysosomes. In these endolysosomal compartments, the E-64 moiety will covalently bind to …

Role Of Type 4 Phosphodiesterases In Thermoregulation And Salivation In Mice, Abigail Grace Boyd

Graduate Theses and Dissertations (2019 - present)

Type 4 cAMP phosphodiesterases (PDE4s) comprise a family of four isoenzymes, PDE4A to D, that hydrolyze and inactivate the second messenger cAMP. Non/PAN selective PDE4 inhibitors, which inhibit all four subtypes simultaneously, produce many promising therapeutic benefits, such as anti-inflammatory or cognition- and memory-enhancing effects. However, unwanted side effects, principally, nausea, diarrhea, and emesis, have long hampered their clinical and commercial success. Targeting individual PDE4 subtypes has been proposed for developing drugs with an improved safety profile, but which PDE4 subtype(s) is/are actually responsible for nausea and emesis remains ill defined. In mice treated with PAN-selective inhibitors, there is substantial …

Alternative Fixation Of Venous Valves For Bioprosthetic Applications, Makenzie Kapales

Biomedical Engineering Undergraduate Honors Theses

Venous valve failure allows for the retrograde, or backward, flow of blood into the lower extremities, which leads to Chronic Venous Insufficiency (CVI). CVI infringes upon quality of life through ulceration and can result in death due to Deep Vein Thrombosis (DVT), or blood clots, causing pulmonary embolism. A successful treatment of CVI restores valve function and prevents retrograde blood flow; however, current bioprosthetic venous valves exhibit low patency and high calcification. To improve upon bioprosthetic venous valves and CVI treatment, the University of Arkansas’s Cardiovascular Biomechanics Lab conducts studies with the purpose of comparing the properties and performance of …

Protein Structure And Interaction: The Role Of Aromatic Residues In Protein Structure And Interactions Between Pyridoxine 5'-Phosphate Oxidase/Dopa Decarboxylase, Mohammed H. Al Mughram

Theses and Dissertations

Naturally developed proteins are capable of carrying out a wide variety of molecular functions due to their highly precise three-dimensional structures, which are determined by their genetically encoded sequences of amino acids. A thorough knowledge of protein structures and interactions at the atomic level will enable researchers to get a deep foundational understanding of the molecular interactions and enzymatic processes required for cells, resulting in more effective therapeutic interventions. This dissertation intends to use structural knowledge from solved protein structures for two distinct objectives.

In the first project, we conducted a bioinformatics structural analysis of experimental protein structures using our …