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2024

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Articles 571 - 600 of 696

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Revolutionizing Our Understanding Of Specific Platelet-Pathogen Interactions, Hammodah Rawhi Hammodah Alfar Jan 2024

Revolutionizing Our Understanding Of Specific Platelet-Pathogen Interactions, Hammodah Rawhi Hammodah Alfar

Theses and Dissertations--Molecular and Cellular Biochemistry

Aside from their classical role in maintaining hemostasis, platelets are considered first-line vascular guardians that influence both the innate and adaptive immune systems. This is mediated by either direct interactions with immune cells or through the release of pre-stored cytokines and chemokines upon interacting with pathogens such as viruses. While this establishes platelets as potential players in the response to pathogens, it remains unclear what platelets can do with pathogens and how important that is to immune responses, especially against viruses. Most systemic viremias, such as HIV-1, present with mild thrombocytopenia, which is mediated through several mechanisms such as a …


Calcium And Proteasomal Regulation Of Er-To-Golgi Protein Transport In Neurons, Samuel A. Galindo Jan 2024

Calcium And Proteasomal Regulation Of Er-To-Golgi Protein Transport In Neurons, Samuel A. Galindo

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Regulatory mechanisms of protein trafficking from the endoplasmic reticulum (ER) are critical to understand since neurodegenerative diseases involve defects in this process leading to chronic ER stress and cell death. This study aimed to better understand the calcium regulatory mechanisms of ER-to-Golgi trafficking in hybrid neuroglioblastoma cells (NG108). Specifically, we asked whether proteasomal degradation of transport machinery was involved in the previously demonstrated upregulation of ER-to-Golgi transport evoked by calcium signaling. Based upon previous literature, we believe that the calcium induced increase in transport is due to the activation of the calcium sensitive regulatory protein apoptosis linked gene 2 (ALG-2) …


Characterization And Evolutionary Analysis Of Poly(Aspartic Acid) Degrading Enzymes: Exploring Enzymes-Dna Interactions And Expanding The Enzyme Family, Thi Ho Jan 2024

Characterization And Evolutionary Analysis Of Poly(Aspartic Acid) Degrading Enzymes: Exploring Enzymes-Dna Interactions And Expanding The Enzyme Family, Thi Ho

College of Graduate Studies: Theses & Dissertations

Poly(aspartic acid) (PAA) has emerged as a biodegradable and environmentally friendly alternative to non- biodegradable polycarboxylates. This thesis aims to further advance the understanding of PAA degradation by exploring multiple facets focusing on PAA-DNA interactions, particularly those involving the enzyme PahZ1 from Pedobacter sp. KP-2, and to investigate their physiological relevance and potential role in the evolution of PAA biodegradation enzymes. Additionally, the research characterizes PahZ1 homologs from various bacterial species, including Brevifollis gellanilyticus, Erythrobacter insulae, Sphingomonadales, and Sphingopyxis sp. Root 1497. These efforts have identified four novel homologs capable of degrading PAA. Synthetic oligopeptides were employed to identify potential …


The Multifunctional Catalytic Hemoglobin Fromamphitrite Ornata: Protocols On Isolation, Taxonomic Identification, Protein Extraction, Purification, And Characterization, Anna L. Husted, Lauren A. Presnar, R. Kevin Blackburn, Joseph L. Staton, Stephen A. Borgiani, Edward L. D'Antonio Jan 2024

The Multifunctional Catalytic Hemoglobin Fromamphitrite Ornata: Protocols On Isolation, Taxonomic Identification, Protein Extraction, Purification, And Characterization, Anna L. Husted, Lauren A. Presnar, R. Kevin Blackburn, Joseph L. Staton, Stephen A. Borgiani, Edward L. D'Antonio

Natural Sciences Faculty Publications

The multifunctional catalytic hemoglobin from the terebellid polychaete Amphitrite ornata, also named dehaloperoxidase (AoDHP), utilizes the typical oxygen transport function in addition to four observed activities involved in substrate oxidation. The multifunctional ability of AoDHP is presently a rare observation, and there exists a limitation for how novel dehaloperoxidases can be identified from macrobenthic infauna. In order to discover more infaunal DHP-bearing candidates, we have devised a facilitated method for an accurate taxonomic identification that places visual and molecular taxonomic approaches in parallel. Traditional visual taxonomic species identification by the non-specialist, at least for A. ornata or even for other …


Submarine Groundwater Discharge At A Mega-Tidal Beach, Raymond D. Craddock, Aaron A. Mohammed, Joseph J. Tamborski, Barret L. Kurylyk Jan 2024

Submarine Groundwater Discharge At A Mega-Tidal Beach, Raymond D. Craddock, Aaron A. Mohammed, Joseph J. Tamborski, Barret L. Kurylyk

OES Faculty Publications

Tidally influenced groundwater systems in coastal environments represent important mixing zones of fresh groundwater and circulating seawater, manifesting as submarine groundwater discharge (SGD). Water circulation induced by tidal pumping enhances the exchange of chemicals between aquifers and coastal waters and thereby influences the biogeochemistry of coastal zones. Here, we report the results of an SGD field study conducted at a steep, mega-tidal sand and gravel beach along the Canadian coast of the Bay of Fundy, a region with the world's highest tides (semi-diurnal tidal ranges exceeding 10 m). Several physical and geochemical measurement techniques were employed to document the spatiotemporal …


Heterogeneity Of Nitrogen Fixation In The Mesopelagic Zone Of The South China Sea, Siqi Wu, Xianhui Sean Wan, Moge Du, Xirong Chen, Corday R. Selden, Mar Benavides, Sophie Bonnet, Carolin R. Löscher, M. Robert Hamersley, Margaret R. Mulholland, Xiuli Yan, Shuh-Ji Kao Jan 2024

Heterogeneity Of Nitrogen Fixation In The Mesopelagic Zone Of The South China Sea, Siqi Wu, Xianhui Sean Wan, Moge Du, Xirong Chen, Corday R. Selden, Mar Benavides, Sophie Bonnet, Carolin R. Löscher, M. Robert Hamersley, Margaret R. Mulholland, Xiuli Yan, Shuh-Ji Kao

OES Faculty Publications

Biological dinitrogen (N₂) fixation, the energetically expensive conversion of N₂ gas to ammonia, plays an essential role in balancing the nitrogen budget in the ocean. Accumulating studies show detectable N₂ fixation rates below the euphotic zone in various marine systems, revealing new insights of marine N₂ fixation. However, the reported rates are highly variable and frequently fall close to detection limits, raising the question of the ubiquity and significance of N₂ fixation in the global dark ocean. Using highly sensitive isotopic labeling incubation including a set of control incubations, we confirm the occurrence of mesopelagic N₂ fixation in the South …


Sphingosine Kinase 2 Depletion Dysregulates Hepatic Redox Metabolism And Enhances Inflammation In Early Metabolic Dysfunction-Associated Steatohepatitis (Mash), Kaitlyn Georgene Jackson Jan 2024

Sphingosine Kinase 2 Depletion Dysregulates Hepatic Redox Metabolism And Enhances Inflammation In Early Metabolic Dysfunction-Associated Steatohepatitis (Mash), Kaitlyn Georgene Jackson

Theses and Dissertations

Metabolic dysfunction-associated steatotic liver disease (MASLD) currently affects one in three people worldwide; its prevalence is growing alongside other cardiometabolic disorders. Aberrations to redox and sphingolipid metabolism contribute to MASLD pathologic progression. Sphingosine-1-phosphate (S1P) is an active lipid, meaning that S1P participates in biochemical processes within the cell. S1P is generated by two distinct isoenzymes, sphingosine kinase (SphK)1 and SphK2. The localization of the SphK enzyme dictates S1P function. While cytosolic SphK1-generated S1P is well-characterized, nuclear and mitochondrial SphK2-generated S1P is less known. Moreover, SphK2 depletion effects on cellular redox processes and inflammation are not well-defined.

This study defines the …


Primary Cilia And Intraflagellar Transport Are Essential Regulators Of Lymphangiogenesis And Modulate Cellular Trafficking Of Ve-Cadherin, Delayna Paulson Jan 2024

Primary Cilia And Intraflagellar Transport Are Essential Regulators Of Lymphangiogenesis And Modulate Cellular Trafficking Of Ve-Cadherin, Delayna Paulson

Electronic Theses and Dissertations

No abstract provided.


Iron–Sulfur Cluster Assembly Scaffold Protein Iscu Is Required For Activation Of Ferric Uptake Regulator (Fur) In Escherichia Coli, Huangen Ding Jan 2024

Iron–Sulfur Cluster Assembly Scaffold Protein Iscu Is Required For Activation Of Ferric Uptake Regulator (Fur) In Escherichia Coli, Huangen Ding

Faculty Publications

No abstract provided.


Development Of Innovative Flocculation Technologies For Agricultural Water Treatment, Noor Haleem Jan 2024

Development Of Innovative Flocculation Technologies For Agricultural Water Treatment, Noor Haleem

Electronic Theses and Dissertations

The development of innovative flocculation technologies is essential for addressing the challenges of agricultural water treatment. These technologies play a crucial role in removing contaminants such as suspended solids and nutrients, thereby ensuring safer water for irrigation and livestock consumption. By enhancing water quality and wastewater management, they contribute significantly to environmental sustainability and public health in agricultural communities. This comprehensive thesis extensively explores various dimensions of flocculation, with a focused effort on methodologies and resources aimed at strengthening sustainability and efficiency. A pivotal aspect of the research involves synthesizing cationic starch (CS), a flocculant derived from an underutilized resource, …


Advancing Biological Applications Through Microfluidic-Based Tool Development, K.M. Taufiqur Rahman Jan 2024

Advancing Biological Applications Through Microfluidic-Based Tool Development, K.M. Taufiqur Rahman

Electronic Theses and Dissertations

This research undertook an interdisciplinary approach, integrating bioengineering, microbiology, molecular biology, and systems biology to investigate bacterial dynamics behavior. Specifically, it delved into the development of microfluidic devices for biological applications such as bacterial cell counts, real-time observation of plant roots (here, specialized lectin-coated microbeads are used that mimic root characteristics), and soil microbe interactions. Furthermore, Next-Generation Sequencing and systems biology methodologies were employed to explore the intricate, multifaceted survival mechanisms of Escherichia coli persister population. Studying and quantifying persisters or testing for the existence of VBNC (viable but nonculturable) is challenging. These experiments require precise counts. It has been …


Design, Synthesis, And Evaluation Of Class Iia Histone Deacetylase (Hdac) Inhibitors, Lauren Nicole Kotsull Jan 2024

Design, Synthesis, And Evaluation Of Class Iia Histone Deacetylase (Hdac) Inhibitors, Lauren Nicole Kotsull

Wayne State University Dissertations

Histone deacetylase (HDAC) proteins are linked to disease states, including cancer, and have become important targets for therapeutic development. Many inhibitors have been developed to target HDAC proteins, including FDA-approved inhibitors Vorinostat (SAHA), Belinostat, Romidepsin, and Panobinostat. These inhibitors non-specifically influence most of the 11 metal-dependent HDAC isoforms, which might contribute to the side effects that patients experience during treatment. The lack of selectivity also diminishes the use of HDAC inhibitors as biomedical research tools. To address these drawbacks, the development of selective inhibitors has been heavily studied. Yet, reported inhibitors are predominantly selective for class I HDAC isoforms (HDACs …


Utilizing Plasmid Dna Hydrogels For Cell-Free Protein Production, Tinotenda Duche Jan 2024

Utilizing Plasmid Dna Hydrogels For Cell-Free Protein Production, Tinotenda Duche

Honors Theses and Capstones

Proteins play an important role in various biological processes and are crucial components in biomedical research and therapeutics. Cell-free protein synthesis (CFPS) has provided a valuable approach for rapid protein production outside living cells, involving both transcription and translation processes. However, traditional CFPS methods encounter challenges such as high cost, relatively low yields, and scalability. The end goal of our project is to incorporate our template into the hydrogel. In this work, we report advancements towards that by trying to optimize our solution of CFPS. Unfortunately, the standards for pDNA hydrogel synthesis are not met by the pDNA production and …


Targeting Bcl6 Transcription Factor In Ovarian Cancer, Allison F. Mackey Jan 2024

Targeting Bcl6 Transcription Factor In Ovarian Cancer, Allison F. Mackey

Honors Theses and Capstones

Ovarian cancer is the most fatal female reproductive cancer, with most cases being diagnosed in late stages, after metastasis has become widespread. This can make ovarian cancer challenging to successfully treat, especially with its high rate of recurrence. The use of small molecule compounds to inhibit overexpressed transcription factors may provide an effective method for treatment. BCL6 is a transcription factor that is abnormally overexpressed in patients with recurring and late-stage ovarian cancer and has been implicated in proliferation and metastatic behavior. The identification of multiple potential inhibitors of BCL6 could improve chances for the further testing of these compounds, …


Assessing Lipid Composition Of Cell Membrane In Escherichia Coli Under Aerobic And Anaerobic Conditions, Isabelle Johnson Jan 2024

Assessing Lipid Composition Of Cell Membrane In Escherichia Coli Under Aerobic And Anaerobic Conditions, Isabelle Johnson

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Escherichia coli is a highly studied model organism that is tightly tied to the mammalian gastrointestinal system. This microorganism has the capability to be a beneficial gut microbe or a life-threatening pathogen. In this study, the lipid membrane of Escherichia coli was investigated using Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) to observe the change in its composition in aerobic and anaerobic conditions. Evidence of desaturation was discovered in the spectra, though more investigation is needed to understand the metabolic processes and drives that result in this change. Elucidation of these pathways in the future could result in …


Discovery Of Dna Aptamers As Probes For Detecting Ranavirus Mcp, Corbin Hudson Jan 2024

Discovery Of Dna Aptamers As Probes For Detecting Ranavirus Mcp, Corbin Hudson

Theses, Dissertations and Culminating Projects

Global amphibian populations have been declining since the late 20th century; one of the most significant contributors to these declines is a genus of viral pathogens known as Ranavirus (Rv). Frog virus 3 is one of these viral agents and is currently found affecting frog populations throughout NJ, MD, PA, DE, and VA. While Frog virus 3 is most known for afflicting frogs, the Ranavirus genus can also infect bony fish species as well as reptiles, allowing for a wide vector of transmission and making its spread a danger both locally and globally. In the absence of a cure, it …


Chemical Biology Approach To Study Rna Modifications, Ya Ying Zheng Jan 2024

Chemical Biology Approach To Study Rna Modifications, Ya Ying Zheng

Legacy Theses & Dissertations (2009 - 2024)

Nucleic acid modifications have gained compelling interest for their pivotal roles in cellular and biological processes. These modifications introduced a new layer of regulation without altering the original genetic sequence. In this burgeoning field of epitranscriptomics, many of the chemical modifications have emerged as potential biomarkers in therapeutic applications. Inosine is an essential post-transcriptional RNA modification that has functional roles in modulating the fate of all RNAs. The enzyme ADAR catalyzes the deamination of adenosine to inosine. This can also lead to change in the eukaryotic transcriptome due to A-G miscoding since inosine preferentially base pairs with cytosine. Moreover, hyper-editing …


Rps6kb1 Is A Critical Target For Overcoming Tumor Lineage Plasticity And Therapy Resistance, Saptadwipa Ganguly Jan 2024

Rps6kb1 Is A Critical Target For Overcoming Tumor Lineage Plasticity And Therapy Resistance, Saptadwipa Ganguly

Theses and Dissertations--Toxicology and Cancer Biology

Most tumors initially respond to treatment, yet refractory clones subsequently develop owing to resistance mechanisms which can be classified as intrinsic or extrinsic resistance. The intrinsic resistance is usually present prior to any treatment whereas the extrinsic resistance develops as a result of exposure to some kind of therapy. In order to target these “therapy resistant” tumor cells an unbiased screen of an FDA-approved drug library against cancer cells was performed. This was followed by synthesis of chemical analogs of the most effective drug.

The studies led to the identification of a derivative of the antihistamine drug ebastine, designated Super-ebastine …


An Rnai-Based Approach To Ips Calligraphus Management: A Promising Strategy For Forest Protection, Mary Wallace Jan 2024

An Rnai-Based Approach To Ips Calligraphus Management: A Promising Strategy For Forest Protection, Mary Wallace

Theses and Dissertations--Entomology

As climate change leads to more frequent and severe extreme weather, host tree stress is increasing the occurrence of large-scale bark beetle outbreaks. One such beetle, Ips calligraphus (Germar), a native bark beetle in the southeastern United States, has traditionally been considered a secondary pest of pine trees. Management has relied on silvicultural practices that enhance forest resilience, enabling host trees to effectively use natural defenses to deter beetle infestation. However, during periods of forest stress caused by storms, droughts, human disturbance, and other factors, beetle outbreaks can cause considerable ecological and economic damage.

Addressing worsening I. calligraphus outbreaks will …


"Hunter-Killer" Peptoid-Peptide Conjugate To Target And Eliminate Cancer Stem Cells, Breanne F. Mcelderry Jan 2024

"Hunter-Killer" Peptoid-Peptide Conjugate To Target And Eliminate Cancer Stem Cells, Breanne F. Mcelderry

Chemistry Theses

In the contemporary paradigm concerning the emergence of therapy-resistant recurrent cancer, recent studies posit the existence of a limited population of self-renewing malignant progenitors known as cancer stem cells (CSCs). The presence of CSCs explains why tumors often relapse despite clinical remission with initial therapeutic interventions. Consequently, the development of innovative therapeutic modalities specifically tailored to target and eliminate CSCs represents a highly promising strategy for eradicating cancer without the risk of recurrence. In previous research, we successfully developed a synthetic peptoid-based ligand CL-1-19-1 that selectively binds to CSC over non-CSC. However, CL-1-19-1 did not exhibit any significant inhibitory effect …


Developing Methods For Analysis Of Chiral Small Molecules And D-Amino Acid Containing Peptides, Joshua I. Putman Jan 2024

Developing Methods For Analysis Of Chiral Small Molecules And D-Amino Acid Containing Peptides, Joshua I. Putman

Chemistry & Biochemistry Dissertations - Archive

This dissertation covers the development of methods to analyze chiral small molecules and d-amino acid containing peptides. The first section covers the development of liquid chromatographic chiral screening approaches for newly synthesized chiral molecules. The next part of the dissertation covers methodologies for the analysis of d-amino acid containing peptides. Lastly the bacterial degradation of three commonly used pesticides by bacteria harvested from Colorado potato beetles (Leptinotarsa decemliniata) is presented.

Twelve new azole compounds and eleven racemic ethanolamine derivatives were synthesized. These twenty-three compounds were evaluated using eight chiral columns, four macrocylic glycopeptides, a cyclodextrin derivative …


Characterization Of Mannanase From Bacillus Subtilis Hm7 And Prebiotic Production, Kornwarin Chumnankul Jan 2024

Characterization Of Mannanase From Bacillus Subtilis Hm7 And Prebiotic Production, Kornwarin Chumnankul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Mannan oligosaccharides (MOS) have been utilized as food and feed additives due to their various advantages, including modulation and regulation of gut microbiota. Moreover, MOS can enhance tight junction activity by activating the AMPK signaling pathway. MOS can be produced by β-mannanase, a widely used enzyme in various industries. This study aims to clone, express, purify, and biochemically characterize the β-mannanase (MAN26HM7/A), and determine substrate specificity and hydrolytic products from konjac, copra meal, and coffee bean. Man26HM7/A was successfully cloned into pET-21b, resulting in pETMan26HM7/A. pETMan26HM7/A was expressed in E. coli BL21, induced by 0.4 mM IPTG at 37 °C …


Identification Of Inhibitors And Inhibitory Mechanisms For Sars-Cov-2 Papain-Like Protease, Auwal Auwal Rabiu Jan 2024

Identification Of Inhibitors And Inhibitory Mechanisms For Sars-Cov-2 Papain-Like Protease, Auwal Auwal Rabiu

Chulalongkorn University Theses and Dissertations (Chula ETD)

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in late 2019 in Wuhan, China, and rapidly spread worldwide. The continuous emergence of SARS-CoV-2 variants necessitates the investigation of viral proteins as potential drug targets. While the main protease (Mpro) has been extensively studied, papain-like protease (PLpro) remains relatively underexplored despite its critical roles in viral replication and the inhibition of host innate immune responses. This study aims to identify and characterize potential inhibitors of SARS-CoV-2 PLpro using a combination of in vitro protease activity assays, enzyme kinetics, molecular docking, molecular dynamics simulations, …


Cloning And Characterization Of Endolevanase From Bacillus Amyloliquefaciens Pd9, Theerapat Tangsupatawat Jan 2024

Cloning And Characterization Of Endolevanase From Bacillus Amyloliquefaciens Pd9, Theerapat Tangsupatawat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Endolevanase (EC 3.2.1.65) from Bacillus amyloliquefaciens PD9 (ENLENPD9) belongs to the glycoside hydrolase family 32 (GH32) that hydrolyzes β-2,6-fructofuranosyl linkages in levan to produce levan-type fructooligosaccharide(L-FOS) of various lengths. The gene encoding this enzyme (enlenPD9), consisting of 1,545 base pairs, was cloned into the pET-21b expression vector to produce ENLENPD9 both with (polyHis-ENLENPD9; 522 amino acids) and without a six-histidine residue tag (6xpolyHis tag) at the C-terminal (ENLENPD9; 514 amino acids) variants. ENLENPD9 and polyHis-ENLENPD9 were optimally expressed in Escherichia coli BL21(DE3) for 3 hours in TB medium with 0.4 mM IPTG and LB medium with 0.25 mM IPTG, respectively, …


Development Of Nanomaterial-Based Electrochemical Detection Devices For Point-Of-Care Testing, Khageephun Permpoka Jan 2024

Development Of Nanomaterial-Based Electrochemical Detection Devices For Point-Of-Care Testing, Khageephun Permpoka

Chulalongkorn University Theses and Dissertations (Chula ETD)

Electrochemical detection aligns with the REASSURED criteria established by the World Health Organization. Nanomaterials also play a crucial role in enhancing detection performance. Therefore, this research integrates nanomaterials into the development of pointof-care testing (POCT) devices for detecting prostate cancer biomarkers and monitoring wound infection status. Timely diagnosis can significantly reduce the physical burden of illness, ease pressure on healthcare systems, and lessen the broader socioeconomic impact. The first part of the research involves the development of a paper-based analytical device for detecting the enzyme myeloperoxidase (MPO). Glucose oxidase (GOx) was immobilized on paper to produce hydrogen peroxide (H2O2 ), …


The Biobehavioral Effects Of Embryonic Exposure To Neural Inflammation And Oxidative Stress In Zebrafish, Dalton J. Anderson Jan 2024

The Biobehavioral Effects Of Embryonic Exposure To Neural Inflammation And Oxidative Stress In Zebrafish, Dalton J. Anderson

Honors College Theses

The purpose of this research is to improve understanding of the neurodevelopmental effects of embryonic exposure to elevated inflammation and oxidative stress induced by the antipyretic drug acetaminophen (APAP). Our study was the first to examine the interactive effects of APAP and inflammation in zebrafish embryos and how the treatments affect brain development and larval behavior. Experimental groups of zebrafish larvae were exposed to lipopolysaccharide (LPS) to induce inflammation, APAP, or LPS + APAP and larval behavior was analyzed using Ethovision automated behavioral tracking software. We also measured changes in whole-brain Glycogen Synthase Kinase 3 Beta (GSK3B) and GSK3B phosphorylation, …


Ca2+ Binding Shifts Dimeric Dual Oxidase's Truncated Ef-Hand Domain To Monomer, Chin-Chuan Wei, Amena Razzak, Hadis Ghasmi Jan 2024

Ca2+ Binding Shifts Dimeric Dual Oxidase's Truncated Ef-Hand Domain To Monomer, Chin-Chuan Wei, Amena Razzak, Hadis Ghasmi

SIUE Faculty Research, Scholarship, and Creative Activity

Hydrogen peroxide, produced by Dual Oxidase (Duox), is essential for thyroid hormone synthesis. Duox activation involves Ca2+ binding to its EF-hand Domain (EFD), which contains two EF-hands (EFs). In this study, we characterized a truncated EFD using spectrometry, calorimetry, electrophoretic mobility, and gel filtration to obtain its Ca2+ binding thermodynamic and kinetics, as well as to assess the associated conformational changes. Our results revealed that its 2nd EF-hand (EF2) exhibits a strong exothermic Ca2+ binding (Ka = 107 M−1) while EF1 shows a weaker binding (Ka = 105 M−1), resulting in the burial of its negatively charged residues. The Ca2+ …


Effect Of Dietary Flavonoids On Growth In Saccharomyces Cerevisiae, Vivian Rivera Jan 2024

Effect Of Dietary Flavonoids On Growth In Saccharomyces Cerevisiae, Vivian Rivera

Mahurin Honors College Capstone Experience/Thesis Projects

Plant foods contain a diversity of biologically active compounds called phytochemicals, produced by plant species as secondary metabolites. A phytochemical group known as flavonoids has received much scientific attention in recent times with respect to their antioxidative and anti-inflammatory roles. This investigation examined how quercetin and naringenin, the most common dietary flavonoids, affect growth potential of yeast under optimal and stress conditions (temperature, glucose, and oxidative stress). Using Saccharomyces cerevisiae as a model, a dose dependency effect of quercetin and naringenin was observed under optimal conditions when liquid cultures were treated with three different concentrations (75 μM, 150 μM, and …


Contributions Of The Replication Initiator Protein Dnaa To Physiology And Virulence Of The Lyme Disease Spirochete, Andrew Krusenstjerna Jan 2024

Contributions Of The Replication Initiator Protein Dnaa To Physiology And Virulence Of The Lyme Disease Spirochete, Andrew Krusenstjerna

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Borrelia burgdorferi, the etiological agent of Lyme disease, is the most prevalent vector-borne disease in the United States. The spirochetal population is naturally maintained by consistently cycling between Ixodid ticks and small vertebrates. To survive within these diverse niches, B. burgdorferi has evolved a unique physiology and regulatory network to sense and respond to environmental fluxes. Replication is a hallmark of the Lyme spirochete’s enzootic life cycle, specifically at the nymphal tick-to-vertebrate interface. The mechanisms and regulatory schema for the basic cellular processes in B. burgdorferi, or indeed any member of the phylum spirochaetota, are largely unknown. The central hypothesis …


Abl1/2 And Ddr1 Cooperate To Stabilize Braf/Craf To Drive Erk1/2 Reactivation And Promote Mek Inhibitor Resistance In Nras-Mutant Melanomas, Anastasia Lyon Jan 2024

Abl1/2 And Ddr1 Cooperate To Stabilize Braf/Craf To Drive Erk1/2 Reactivation And Promote Mek Inhibitor Resistance In Nras-Mutant Melanomas, Anastasia Lyon

Theses and Dissertations--Pharmacology and Nutritional Sciences

This study addresses the escalating incidence of NRAS-mutant melanomas, a type of skin cancer lacking FDA-approved targeted therapies. Despite ongoing research targeting the RAF/MEK/ERK pathway, existing drugs fail to enhance progression-free survival due to acquired resistance. This project identifies a novel role for ABL1/2 and DDR1 kinases in driving drug resistance and proliferation of NRAS-mutant melanoma cells. ABL1/2 and DDR1 cooperate to promote RAF homodimerization and protein stability in order to reactivate MEK/ERK signaling to drive MEK1/2 inhibitor (MEKi) resistance and promote survival of resistant cells. By targeting ABL1/2 and DDR1 with nilotinib, a FDA-approved anti-leukemic inhibitor, we …