Biochemistry, Biophysics, and Structural Biology Commons^™

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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 …

The Delineation Of Platelet Pathology In Cardiometabolic Disease, Chi Peng

Theses and Dissertations--Pharmacology and Nutritional Sciences

Obesity is a multifactorial disease with many comorbidities leading to multiorgan dysfunction. Current studies point towards dysregulation of platelet signaling as a driver for increased risk of cardiovascular disease and stroke. The exact mechanisms remain elusive due to the complex interplay of factors involved, warranting the need to further understand how platelets are affected. Our preliminary data evaluating changes in platelet and coagulation parameters from bariatric patients showed that obesity did not affect platelet count or clotting time as demonstrated in INR values. However, female patients had increased bleeding events before surgery that were decreased after surgery. Due to limitations …

Practical Challenges In Delivering Dsrna For Woody Plant Protection, Zachary Bragg

Theses and Dissertations--Entomology

Unprecedented weather events associated with climate change, coupled with extensive anthropogenic stresses, have reduced the effectiveness of traditional forest pest management approaches, which can no longer keep pace with invasive species overwhelming naïve landscapes and native pests experiencing eruptive and expansive outbreaks. Double-stranded RNA-(dsRNA) mediated gene silencing, a type of RNA interference (RNAi), has been coopted for use as a biopesticide against a multitude of agricultural and horticultural pests and could serve as a powerful tool for woody plant protection. While effective initiation of gene silencing and subsequent mortality have been demonstrated in multiple tree pests, effective and efficient methods …

Role Of Autophagy-Related Genes In Lipid Transport For Efficient Replication Of Tombusviruses, Yuanrong Kang

Theses and Dissertations--Plant Pathology

Tombusviruses are positive-strand RNA viruses, which utilize numerous co-opted host factors and massive de-novo synthesized membrane resources to modify host membranes and form large viral replication organelles (VROs). Among plenty of host cellular processes, autophagy emerges as a potential membrane resource for VROs formation due to its ability to de-novo generate the double membrane structures, known as autophagosomes. Besides, as an important host defense pathway, autophagy is also a target for tombusviruses to prevent its antiviral activities. In this study, I identify the role of key autophagy related genes, Atg11, Atg8, and Atg2, which are involved in autophagosome formation, and …

Development Of Functional Plasmonic Nanoceria For The Ultrasensitive Detection Of Ebola Glycoprotein, Carissa A. Sutton

Graduate Theses/Dissertations

Infectious diseases have been increasing in both severity and prevalence, leading to increasing economic burdens and health concerns. Ebola hemorrhagic fever is an infectious disease that is both highly communicable and highly fatal. Current detection methods for the virus have high specificity and sensitivity but have long and/or complicated procedures that do not allow for early virus detection in highly affected areas. Compared to the lengthy procedure of reverse transcription-polymerase chain reaction (RT-PCR), real-time RT-PCR is more time-efficient; however, specificity and sensitivity are reduced. Since early detection of the virus is the only way to increase survival rates, sensitive detection …

Inflammation And Tumor Progression: The Differential Impact Of Saa In Breast Cancer Models, Daniel Wilhelm Olivier, Carla Eksteen, Manisha Du Plessis, Louis De Jager, Lize Engelbrecht, Nathaniel Wade Mcgregor, Preetha Shridas, Frederick C. De Beer, Willem J. S. De Villiers, Etheresia Pretorius, Anna-Mart Engelbrecht

Saha Cardiovascular Research Center Faculty Publications

Background: Previous research has shown that the Serum Amyloid A (SAA) protein family is intricately involved in inflammatory signaling and various disease pathologies. We have previously demonstrated that SAA is associated with increased colitis disease severity and the promotion of tumorigenesis. However, the specific role of SAA proteins in breast cancer pathology remains unclear. Therefore, we investigated the role of systemic SAA1 and SAA2 (SAA1/2) in a triple-negative breast cancer mouse model.

Methods: Syngeneic breast tumors were established in wild-type mice, and mice lacking the SAA1/2 (SAADKO). Subsequently, tumor volume was monitored, species survival determined, the inflammatory profiles of mice …