Biochemistry Commons^™

Novel Photobase Generators For Photoinduced Polymerization And Ph Regulation, Shupei Yu

Dissertations

Photochemistry encompasses the investigation of chemical processes instigated by light absorption. As important branches of photochemistry, photosensitive and optical materials have attracted extensive research interests in both academia and industry. Photosensitive and optical materials are composed of polymers / small molecules with photo-responsive properties. These materials not only can absorb light in the desired energy spectrum, but also exhibit chemical / physical reactions, which can be applied to different fields such as photoredox, photo-heat, phototherapy, solar cells, diodes, etc. Among them, photobase generators (PBGs) are a series of photosensitive compounds, which absorb the incident light, then release the basic species …

Developing Regulated Crispr Systems To Control Bacterial Microbiomes, Gregory M. Pellegrino

Electronic Thesis and Dissertation Repository

Changes to the human microbiome’s composition and metabolome are associated with numerous diseases and alterations to xenobiotic metabolism. As such, targeting the human microbiome is an increasingly popular option for therapeutic interventions. However, traditional therapies that target the microbiome such as antibiotics lack specificity, which can affect the beneficial species of the microbiome and cause adverse health outcomes such as the rise of antimicrobial-resistant bacteria. Therefore, the research and development of specific, targeted antimicrobial therapies is crucial to effectively treating microbiome dysbioses.
CRISPR and CRISPRi provide easily modifiable, RNA-guided mechanisms mediated by the Cas9 or dCas9 enzymes to induce sequence-specific …

On The Anti-Adipogenic Function Of Collagen Triple Helix Repeat-Containing Protein 1, Matthew E. Siviski

Electronic Theses and Dissertations

Adipogenesis is regulated by the coordinated activity of adipogenic transcription factors, including PPAR-gamma (PPARG) and C/EBP alpha (CEBPA). Thus, dysregulated adipogenesis predisposes adipose tissues to adipocyte hypertrophy and hyperplasia. We have previously reported that mice possessing a homozygous null gene mutation in collagen triple helix repeat-containing protein 1 (CTHRC1) have increased adiposity compared to wildtype mice, supporting the concept that CTHRC1 regulates body composition. Herein, we investigated the anti-adipogenic activity of CTHRC1. Using 3T3-L1 preadipocytes, we showed significantly reduced adipogenic differentiation in the presence of CTHRC1 commensurate to marked suppression of Cebpa and Pparg gene expression. In addition, CTHRC1 increased …

Role Of Prmt5 In Ulk1-Mediated Autophagy And Breast Cancer Therapy, Charles Brobbey

MUSC Theses and Dissertations

PRMT5 (Protein arginine methyltransferase 5) is the predominant type II PRMT that monomethylates and symmetrically dimethylates arginine residues of histone and none- histone proteins to regulate diverse cellular processes. PRMT5 overexpression has been implicated in tumorigenesis and other diseases and has gained trac1on as a poten1al an1tumor target with some of its inhibitors being tested in clinical trials. Despite the well- established an1tumor effect of PRMT5 inhibitors, how the efficacy of these inhibitors is regulated is unexplored. We show in this study that autophagy blockage enhances cellular sensi1vity to PRMT5 inhibitor in triple nega1ve breast cancer cells. Both gene1c deple1on …

Biophysical Factors Affecting Habitat Suitability For Crassostrea Virginica, Jason D. Tilley

Dissertations

Oyster reefs provide a variety of important ecosystem services. However, the mortality rate of eastern oyster, Crassostrea virginica, the dominant species that produces oyster reefs in the northern Gulf of Mexico, is increasing at an alarming rate due to a variety of abiotic and biological factors. I examined how biophysical factors, including the less-studied fatty acid profiles of the suspended particulate matter on which oysters feed, influenced morphometric condition of C. virginica.

I sampled suspended particulate matter (SPM) and oysters in-situ in the western Mississippi Sound, which historically supported the majority of oyster production in Mississippi waters. Sampling …

Diaryl Oxazoles As Cleavable Linkers For Drug Discovery Platforms, Elizabeth Taggart

Honors Theses

Within the field of medicine and pharmacology, discovering small molecule or biologic based molecules with therapeutic potential is a difficult task. Current methods involve individually screening hundreds of compounds on a potential target biomolecule, and recent technologies have explored peptide encoded libraries (PELs) as a means of making this screening process more high-throughput. These libraries produce a large number of small molecule drug candidates each conjugated to a unique peptide fragment, functioning as a barcode. Analysis of PELs requires the capture of hit small molecules and the subsequent release of their peptide tags; however, current approaches are limited in their …

Synthesis Of Bacterial Glycerophospholipids For Biomembrane Model Studies: A Means To Advanced Biofuels, Felix Adulley

Electronic Theses and Dissertations

To reduce reliance on fossil fuels, sustainable biofuels are being pursued, especially advanced biofuels like 1-butanol that have higher energy content and greater compatibility with existing infrastructure than ethanol. A persistent challenge is the yield-limiting toxicity of biofuels and process solvents, such as tetrahydrofuran, to the microbes that ferment biomass into biofuel. The cell membrane is a focal point of toxicity, and understanding how it interacts with fuels and solvents is key to improving yield. Phospholipid bilayers are the core of biomembranes, and model biomembranes of defined composition provide the ideal platform for biophysical studies. To this end, glycerophospholipids characteristic …

Flavonol Glucosylation: A Structural Investigation Of The Flavonol Specific 3-O Glucosyltransferase Cp3gt, Aaron S. Birchfield

Electronic Theses and Dissertations

Flavonoid glycosyltransferases (GTs), enzymes integral to plant ecological responses and human pharmacology, necessitate rigorous structural elucidation to decipher their mechanistic function and substrate specificity, particularly given their role in the biotransformation of diverse pharmacological agents and natural products. This investigation delved into a comprehensive exploration of the flavonol 3-O GT from Citrus paradisi (Cp3GT), scrutinizing the impact of a c-terminal c-myc/6x histidine tag on its enzymatic activity and substrate specificity, and successfully achieving its purification to apparent homogeneity. This established a strong foundation for potential future crystallographic and other structure/function analyses. Through the strategic implementation of site-directed mutagenesis, a thrombin …

The Identification Of Small Molecule Inhibitors To Candida Albicans Phosphatidylserine Synthase, Yue Zhou

Doctoral Dissertations

Candida albicans phosphatidylserine (PS) synthase, encoded by the CHO1 gene, has been identified as a potential drug target for new antifungals against systemic candidiasis due to its importance in virulence, absence in the host and conservation among fungal pathogens. This dissertation is focused on the identification of inhibitors for this membrane enzyme. Cho1 has two substrates: cytidyldiphosphate-diacylglycerol (CDP-DAG) and serine. Previous studies identified a conserved CDP-alcohol phosphotransferase (CAPT) binding motif present within Cho1, and here we revealed that mutations in all but one conserved amino acid within the CAPT motif resulted in decreased Cho1. For serine, we have predicted a …

Characterization Of Lignin Structural Variability And The Associated Application In Genome Wide Association Studies, Nathan D. Bryant

Doctoral Dissertations

Poplar (Populus sp.) is a promising biofuel feedstock due to advantageous features such as fast growth, the ability to grow on marginal land, and relatively low lignin content. However, there is tremendous variability associated with the composition of biomass. Understanding this variability, especially in lignin, is crucial to developing and implementing financially viable, integrated biorefineries. Although lignin is typically described as being comprised of three primary monolignols (syringyl, guaiacyl, p-hydroxyphenyl), it is a highly irregular biopolymer that can incorporate non-canonical monolignols. It is also connected by a variety of interunit linkages, adding to its complexity. Secondary cell wall …

A Cancer-Specific Study On The Differentially Expressed Protein-Protein Interactions Of Fumarate Hydratase, Sydney Lac

Dissertations & Theses (Open Access)

Fumarate hydratase (FH) is an enzyme used in the Krebs Cycle to convert fumarate to malate, and it is controlled by the FH gene. In this paper, we will investigate its role in Uterine Corpus Endometrial Carcinoma (UCEC) and how FH-deficient cells affect tumorigenesis. It is well-established that FH has been extensively studied in connection with renal cell carcinoma, skin and uterine leiomyomas, pheochromocytoma, and paraganglioma. However, we aim to construct an interaction network of significant genes related to the FH gene under conditions of FH deficiency in the Kreb Cycle. Creating an interactive network that illustrates the interconnectedness of …

Biochemical And Kinetic Analysis Of Phosphofructokinase In The Eukaryotic Human Pathogen Entamoeba Histolytica, Jin Cho

All Dissertations

Entamoeba histolytica is a water- and food-borne intestinal parasite that causes amoebiasis and liver abscess in ~100 million people each year leading to ~100,000 deaths. This amitochondriate parasite lacks many metabolic pathways including the tricarboxylic acid cycle and oxidative phosphorylation, and cannot synthesize purines, pyrimidines, or most amino acids. As a result, E. histolytica is presumed to rely on its modified pyrophosphate (PP_i)-dependent glycolytic pathway for ATP production during growth on glucose. This pathway relies on a PP_i-dependent rather than ATP-dependent phosphofructokinase (PFK) and thus has a net production of three ATP per glucose. However, in …

The Discovery Of Diverse Picophytoplankton Populations In The Columbia And Willamette Rivers Using Flow Cytometry, Kylee Brevick

Chemistry Undergraduate Departmental Honors Theses

As important primary producers, picophytoplankton determine the flow of carbon and energy in aquatic ecosystems. Picocyanobacteria are one picophytoplankton group known to be dominant in oceans and lakes, but they are still poorly understood in river systems. This project examined picophytoplankton communities in two distinct river systems: the Columbia and Willamette Rivers in Portland, Oregon. I aimed to characterize and quantify the picophytoplankton populations in the context of the environmental conditions of the two rivers. I used flow cytometry to detect cells based on their relative size and pigment fluorescence. I sampled nearly weekly for ten months to capture population …

Interfacial Interactions Between Engineered Nanoplastics And Biological Systems: Towards An Atomic And Molecular Understanding Of Plastics- Driven Cellular Dyshomeostasis, Afroz Karim

Open Access Theses & Dissertations

The persistent presence of micro (nano) plastics in our environment has raised concerns regarding potential health risks associated with human exposure. With the extensive use of plastic materials and the widespread consumption of plastic-contaminated food items, two types of microplastics, polystyrene (PS) and polymethylmethacrylate (PMMA), have attracted increased attention. While the adverse effects of microplastics on animals and marine life have been extensively studied, their potential impact on human health remains largely unexplored. Specifically, the interaction between microplastics and biomolecules within the human body and their effect on human health have yet to be comprehensively investigated. This dissertation study focuses …

Biochemical Analyses Of Udgx-A Crosslinking Uracil-Dna Glycosylase, Chuan Liang

All Dissertations

DNA base damage is common due to exposure to various endogenous and exogenous factors. To repair the base lesions, such as uracil from cytosine deamination, enzymes from the uracil-DNA glycosylase (UDG) superfamily are critical, which can recognize the damaged base and initiate the base excision repair (BER) pathway. There used to be six families of proteins identified in the UDG superfamily until a new member, UDGX, was found in Mycobacterium smegmatis, which is a unique DNA-crosslinking UDG. In this dissertation work, a series of biochemical analyses of the newly found UDGX are performed, including the analyses of structures, functions, …

Characterization Of The Effects Of The Pyrazolopyrimidine Inhibitor Grassofermata (Nav-2729) In The Eukaryotic Pathogen Trypanosoma Brucei, Kristina Marie Parman

All Dissertations

The protozoan pathogen, Trypanosoma brucei, is the causative agent of sleeping sickness in humans and nagana in livestock in sub-Saharan Africa. T. brucei cycles between tsetse fly and mammalian hosts, and it is adapted to survive in diverse host tissues. Variant Surface Glycoprotein (VSG) plays a key role in immune evasion in the mammalian host. The VSG membrane anchor requires two myristates, 14-carbon saturated fatty acids (FAs) that are scarce in the host. T. brucei can synthesize FAs de novo, but also readily takes up exogenous FAs, despite lacking homologs to fatty acid uptake proteins found in other …

Amyloid Fibrils Of Human Fgf-1 Induced By Different Detergents, Zeina Ismael Ibrahem Alraawi

Graduate Theses and Dissertations

Nature achieves molecular self-assembly through the ordered growth of nanoscale building blocks with high efficiency to fabricate macromolecular architectures. One example of self- assembly is peptides folding onto protein is one of the most astounding biological self-assembly processes. When proteins aggregate to form amyloid fibers, the secondary structure of the protein converts from its native state to a cross-beta-sheet. Fibroblast growth factors (FGFs) possess an essential role in neuronal survival during development. In addition, they are involved in neural stem cell (NSC) proliferation. Fibroblast growth factors (FGFs) are well known to be synthesized in the central nervous system (CNS) and …

Characterization Of Human Fibroblast Growth Factor 2 Variant To Determine Effects On Structure, Stability, And Cell Proliferation, Ryan Layes

Graduate Theses and Dissertations

Fibroblast growth factors (FGFs) are a family of cell signaling proteins conserved across multiple species. Each individual FGF elicits different cellular functions including, but not limited to, proliferation, migration, differentiation, angiogenesis, and wound healing. One of the most studied members, fibroblast growth factor 2 (FGF2), has demonstrated substantial wound healing capacity in a wide range of tissues including skeletal, muscular, neural, respiratory, epithelial, and cardiovascular. This ability makes FGF2 a potential therapeutic for a wide range of conditions and injuries. However, due to a short half-life at room temperature, therapeutic use of FGF2 is limited. It has been demonstrated that …

Integration Of Algae And Biomass Processes To Synthesize Renewable Bioproducts For The Circular Economy, Jessica Martin

USF Tampa Graduate Theses and Dissertations

Rapid population growth and global industrialization have substantially heightened the demand for fossil-based fuels and products in various sectors of the global economy, including energy production, transportation fuels, and as raw materials for petrochemicals. The intense consumption of fossil fuels has caused immense environmental impacts, especially pertaining to carbon dioxide emissions. Shifting to renewable feedstocks (raw materials) is expected to reduce these emissions by lowering the carbon footprint of fuels and products compared to traditional fossil-derived alternatives. This transition aligns with the goal of creating a sustainable and circular economy, emphasizing efficient resource use, and reducing waste generation through recycling …

Caulobacter Clpxp Adaptor Popa’S Domain Interactions In The Adaptor Hierarchy Of Ctra Degradation, Thomas P. Scudder

Masters Theses

The degradation and recycling of protein is a process essential for the maintenance and regulation of cellular function. More specifically, in Caulobacter crescentus, the ClpXP protease is responsible for driving progression through the cell cycle and protein quality control. This protease utilizes three known adaptors to selectively degrade proteins that initiate different stages of development. This thesis will elaborate on the specific binding interface on one of these adaptors, PopA, with another, RcdA, and focus in on specific residues on PopA and investigate their roles in adaptor binding and delivery of CtrA, the master regulator of Caulobacter. Finally, I …

Combining Simulation And The Mspa Nanopore To Study P53 Dynamics And Interactions, Samantha A. Schultz

Masters Theses

p53 is a transcription factor and an important tumor suppressor protein that becomes activated due to DNA damage. Because of its role as a tumor suppressor, mutations in the gene that encodes it are found in over 50% of human cancers. The N-terminal transactivation domain (NTAD) of p53 is intrinsically disordered and modulates the function and interactions of p53 in the cell. Its disordered structure allows it to be controlled closely by post-translation modifications that regulate p53’s ability to bind DNA and interact with regulatory binding partners. p53 is an attractive target for developing cancer therapeutics, but its intrinsically disordered …

Binding Interactions Of Biologically Relevant Molecules Studied Using Surface-Modified And Nanostructured Surfaces, Palak Sondhi

Dissertations

This research focuses on the field of surface nanobioscience, wherein different nanosurfaces that will be used as working electrodes in the electrochemical cell are manufactured and surface modified to understand the critical binding interactions between biologically significant molecules like proteins, carbohydrates, small drug molecules, and glycoproteins. This research is essential if we are to determine whether a synthetic molecule can serve as a therapeutic candidate or diagnose a disease in its early stages. In order to fully understand the binding interactions, the study begins with defining some of the fundamental concepts, principles, and analytical tools for biosensing.

Afterwards, we addressed …

Canagliflozin Ameliorates Autistic-Like Features And Mitigates Brain Oxidative Stress Levels In Valproic Acid-Induced Autism In Rats, Mohammad Moutaz Nakhal

Theses

Autism spectrum disorder (ASD) is a neurodevelopmental disease with a substantially increasing incidence rate. It is mainly characterized by repetitive behavior, intellectual difficulties, social communication and interactions deficits. Many medications, dietary supplements, and behavioral treatments have been recommended for ASD management, however, there is no cure yet. Recent studies have examined the therapeutic potential of the sodium-glucose cotransporter 2 (SGLT2) inhibitors in neurodevelopmental diseases, based on their proved anti-inflammatory and antioxidant effects. The main objective of this study is to assess the ability of canagliflozin in improving the behavioural characteristics of autistic rats and investigate the efficacy of canagliflozin in …

Acetylation Regulates Thioredoxin Reductase Activity And Oligomerization, David E. Wright

Electronic Thesis and Dissertation Repository

The Thioredoxin (Trx) system provides the cell with robust defense against oxidative stress and regulates the function of nearly every cellular process through the reduction-oxidation (redox) regulation of proteins. The Trx system is involved in the development of many diseases ranging from cancer to cardiovascular disorders. Thioredoxin reductase (TrxR) is the key enzyme in the Trx system and contains the 21^st genetically encoded amino acid, selenocysteine (Sec). There were multiple experimentally identified TrxR acetylation sites with an unknown effect on TrxR activity. My thesis tested the hypothesis that programmed protein acetylation will enhance the activity of TrxR1. I used …

Short-Term Versus Long-Term Effects Of Nitrogen Addition And Warming On Ecosystem N Dynamics In A Grass-Dominated Temperate Old Field, Benjamin F. A. Souriol

Electronic Thesis and Dissertation Repository

Increased atmospheric nitrogen (N) deposition and climate warming are both anticipated to influence the ecosystem N dynamics of northern temperate ecosystems substantially over the next century. Nevertheless, in field experiments with N addition and warming treatments, temporal scale can play an important role in determining the extent of treatment effects on N dynamics, and it is unclear to what extent the results of short-term studies can be extrapolated to responses over longer time scales. I compared the short-term versus long-term effects of N addition and warming on net N mineralization, N leaching, and N retention in a grass-dominated old field. …

Structural Insights Into The Cl-Par-4 Protein: Ionic Requirements, Conformational Transitions, And Interaction With Cisplatin, Krishna Kumar Raut

Chemistry & Biochemistry Theses & Dissertations

Cancer continues to be the leading global cause of death, with challenges in early diagnosis, drug resistance, non-specific drug targeting, and cancer recurrence and metastasis posing formidable obstacles in cancer therapy. In this context, Prostate Apoptosis Response-4 (Par-4), a pro-apoptotic tumor suppressor protein, emerged as a promising therapeutic target due to its ability to selectively induce apoptosis in cancer cells, thereby minimizing the drug-associated adverse effects. However, a comprehensive understanding of the structural features of Par-4, specifically the caspase-cleaved fragment (cl-Par-4), is crucial for therapeutic advancements.

This dissertation investigated the effects of various ions, both monovalent and divalent, on the …

A Tale Of Two Mechanisms: Is The P53 Modulator Coti-2 A Zinc Chaperone Instead?, Irem Simsek

Electronic Theses and Dissertations

The tumor protein p53 plays a vital role in regulating protein pathways that determine the fate of cells. Any interference with p53 function can cause disruptive cell proliferation and carcinogenesis. The p53 protein experiences a high frequency of mutation in human cancers, leading to significant research efforts to target mutant p53 and restore the normal functioning of p53. The COTI-2 small molecule, developed by COTINGA Pharmaceuticals through a computational program, has entered Phase I clinical trials. Although the mechanism of action is not fully understood, it has shown considerable promise in targeting cell lines with mutant p53. COTI-2 is believed …

Characterization Of Dna Regulatory Elements Of The Highly Abundant Secreted Protein 1 (Hasp1) Promoter And Analysis Of Transcriptomic Responses Under Phosphate Depletion In The Diatom Phaeodactylum Tricornutum, Mahsa Farmanbar

Electronic Thesis and Dissertation Repository

Phosphorus (P) is essential for all life. The bioavailability of phosphorus in oceans impacts diatoms like Phaeodactylum tricornutum (P. tricornutum). P. tricornutum is extensively used in transcriptomic studies to understand pathways involved in P-acquisition. However, activation mechanisms and roles of regulatory elements in P-acquisition responses remains unclear. Here, I deleted predicted phosphate regulatory sites in P.tricornutum’s HASP1 promoter to create different HASP1-eGFP constructs. Under P-depletion, two constructs showed increased eGFP secretion. Additionally, a HASP1 knockout strain was grown under different phosphorus sources to determine if HASP1 is a phytase. Cells grown in full phosphorus utilized organic …

Protein Stability In Solution And In The Gas Phase., Yousef Haidar

Electronic Thesis and Dissertation Repository

Electrospray Ionization mass spectrometry (ESI-MS) is widely used for probing proteins, yet many aspects of this technique remain elusive. Using MS, ion mobility spectrometry (IMS), and circular dichroism (CD) spectroscopy, this thesis sheds light on the stability differences of proteins in the gas phase and solution. After a general introduction (Chapter 1), Chapter 2 scrutinizes some aspects of native ESI. Our data highlight the significance of cone voltage in maintaining a native-like fold and show the advantage of using NH₄Ac in protein experiments. Chapter 3 focuses on hydrogen/deuterium exchange (HDX)-MS. Several studies have reported that D₂O …

Development Of Antiviral Peptidomimetics, Songyi Xue

USF Tampa Graduate Theses and Dissertations

Protein-protein interactions (PPIs) are essential for biological processes and are associated with a number of diseases, including cancer, infectious diseases, and neurodegenerative diseases. As a result, modulation of PPIs has been recognized as one of the most promising strategies to develop the novel drugs. Peptide modulators always exhibit higher specificity and affinities with targets than small compounds or monoclonal antibodies, but their broad medicinal effectiveness is constrained by their poor bioavailability and biostability. Peptidomimetics, which have been developed to mimic the structure as well as function of bioactive peptides and proteins, have shown excellent potential in protein surface mimicry and …