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Biochemistry, Biophysics, and Structural Biology

2020

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Articles 31 - 60 of 795

Full-Text Articles in Life Sciences

Structural Insights Into Host-Pathogen Interactions Of Alphaviruses, Katherine Basore Dec 2020

Structural Insights Into Host-Pathogen Interactions Of Alphaviruses, Katherine Basore

Arts & Sciences Electronic Theses and Dissertations

Alphaviruses are arthropod-borne, single-stranded positive-sense RNA viruses of the Togaviridae family that infect various vertebrates worldwide in tropical and temperate areas, causing emerging and reemerging diseases in humans. Mature virions are 70 nm in diameter and contain a ~11-kilobase genome encapsidated within a nucleocapsid core, a host-derived lipid bilayer, and an envelope comprised of heterodimers of the glycoproteins E1 and E2 arranged into trimeric spikes with T=4 icosahedral symmetry. Alphaviruses are categorized into two groups based on their clinical symptoms: the arthritogenic alphaviruses, such as chikungunya (CHIKV), Mayaro (MAYV), Ross River (RRV), Semliki Forest (SFV), and O’nyong-nyong (ONNV) viruses, which …


Advances In The Understanding Of Auxin Signaling Through Indirect Mechanisms, Ryan Joseph Emenecker Dec 2020

Advances In The Understanding Of Auxin Signaling Through Indirect Mechanisms, Ryan Joseph Emenecker

Arts & Sciences Electronic Theses and Dissertations

The plant hormone auxin is remarkable in its capacity to seemingly regulate all plant growth and developmental processes. Because of this, plants have evolved numerous mechanisms to allow for specific responses to auxin dependent on tissue type and developmental stage. Despite the importance of this specificity, we understand very little with respect to the molecular mechanisms underlying it. In this work, we examine two mechanisms used by plants to modulate auxin response across different tissues. First, we describe our finding that auxin interactions with another plant hormone, abscisic acid, is used as a mechanism to regulate auxin responsiveness in the …


Pathway‐Extended Gene Expression Signatures Integrate Novel Biomarkers That Improve Predictions Of Patient Responses To Kinase Inhibitors, Ashis Bagchee‐Clark, Eliseos J. Mucaki, Tyson Whitehead, Peter Rogan Dec 2020

Pathway‐Extended Gene Expression Signatures Integrate Novel Biomarkers That Improve Predictions Of Patient Responses To Kinase Inhibitors, Ashis Bagchee‐Clark, Eliseos J. Mucaki, Tyson Whitehead, Peter Rogan

Biochemistry Publications

Cancer chemotherapy responses have been related to multiple pharmacogenetic biomarkers, often for the same drug. This study utilizes machine learning to derive multi‐gene expression signatures that predict individual patient responses to specific tyrosine kinase inhibitors, including erlotinib, gefitinib, sorafenib, sunitinib, lapatinib and imatinib. Support vector machine (SVM) learning was used to train mathematical models that distinguished sensitivity from resistance to these drugs using a novel systems biology‐based approach. This began with expression of genes previously implicated in specific drug responses, then expanded to evaluate genes whose products were related through biochemical pathways and interactions. Optimal pathway‐extended SVMs predicted responses in …


Nek1 Phosphorylation Of Yap Promotes Its Stabilization And Transcriptional Output, Md Imtiaz Khalil, Ishita Ghosh, Vibha Singh, Jing Chen, Haining Zhu, Arrigo De Benedetti Dec 2020

Nek1 Phosphorylation Of Yap Promotes Its Stabilization And Transcriptional Output, Md Imtiaz Khalil, Ishita Ghosh, Vibha Singh, Jing Chen, Haining Zhu, Arrigo De Benedetti

Molecular and Cellular Biochemistry Faculty Publications

Most prostate cancer (PCa) deaths result from progressive failure in standard androgen deprivation therapy (ADT), leading to metastatic castration-resistant PCa (mCRPC); however, the mechanism and key players leading to this are not fully understood. While studying the role of tousled-like kinase 1 (TLK1) and never in mitosis gene A (NIMA)-related kinase 1 (NEK1) in a DNA damage response (DDR)-mediated cell cycle arrest in LNCaP cells treated with bicalutamide, we uncovered that overexpression of wt-NEK1 resulted in a rapid conversion to androgen-independent (AI) growth, analogous to what has been observed when YAP1 is overexpressed. We now report that overexpression of wt-NEK1 …


Sestrins: Emerging Dynamic Stress-Sensors In Metabolic And Environmental Health, Seung Hyun Ro, Julianne Fay, Cesar I. Cyuzuzo, Yura Jang, Naeun Lee, Hyun Seob Song, Edward N. Harris Dec 2020

Sestrins: Emerging Dynamic Stress-Sensors In Metabolic And Environmental Health, Seung Hyun Ro, Julianne Fay, Cesar I. Cyuzuzo, Yura Jang, Naeun Lee, Hyun Seob Song, Edward N. Harris

Department of Biochemistry: Faculty Publications

Proper timely management of various external and internal stresses is critical for metabolic and redox homeostasis in mammals. In particular, dysregulation of mechanistic target of rapamycin complex (mTORC) triggered from metabolic stress and accumulation of reactive oxygen species (ROS) generated from environmental and genotoxic stress are well-known culprits leading to chronic metabolic disease conditions in humans. Sestrins are one of the metabolic and environmental stress-responsive groups of proteins, which solely have the ability to regulate both mTORC activity and ROS levels in cells, tissues and organs. While Sestrins are originally reported as one of several p53 target genes, recent studies …


Computer Simulations Of Biological Systems: From Protein Dynamics To Drug Discovery, Rupesh Agarwal Dec 2020

Computer Simulations Of Biological Systems: From Protein Dynamics To Drug Discovery, Rupesh Agarwal

Doctoral Dissertations

Computational biophysics methods such as molecular dynamics (MD) simulations are often used in combination with experimental techniques like neutron scattering, NMR, and FTIR to explore protein conformational landscapes. With the improvements in experimental techniques, there is also a need to continually optimize the MD forcefield parameters to make precise predictions that match experimental results. To complement many of these experiments, an accurate model of deuteration is frequently required, but has been elusive. In our work, we developed a novel method to capture isotope effects in classical MD simulations by re-parameterization of the bonded terms of the CHARMM forcefield using quantum …


Probing Structure, Function And Dynamics In Bacterial Primary And Secondary Transporter-Associated Binding Proteins, Shantanu Shukla Dec 2020

Probing Structure, Function And Dynamics In Bacterial Primary And Secondary Transporter-Associated Binding Proteins, Shantanu Shukla

Doctoral Dissertations

Substrate binding proteins (SBPs) are ubiquitous in all life forms and have evolved to perform diverse physiological functions, such as in membrane transport, gene regulation, neurotransmission, and quorum sensing. It is quite astounding to observe such functional diversity among the SBPs even when they are restricted by their fold space. Therefore, the SBPs are an excellent set of proteins that can reveal how proteins evolution novel function in a structurally conserved/constrained fold. This study attempts to understand the phenomenon of affinity and specificity evolution in SBPs by combining a set of biochemical, biophysical, and structural studies on the SBPs involved …


Development Of Computational Tools To Target Microrna, Luo Song Dec 2020

Development Of Computational Tools To Target Microrna, Luo Song

Dissertations & Theses (Open Access)

MicroRNAs (a.k.a, miRNAs) play an important role in disease development. However, few of their structures have been determined and structure-based computational methods remain challenging in accurately predicting their interactions with small molecules. To address this issue, my thesis is to develop integrated approaches to screening for novel inhibitors by targeting specific structure motifs in miRNAs. The project starts with implementing a tool to find potential miRNA targets with desired motifs. I combined both sequence information of miRNAs and known RNA structure data from Protein Data Bank (PDB) to predict the miRNA structure and identify the motif to target, then I …


Physical Drivers Facilitating A Toxigenic Cyanobacterial Bloom In A Major Great Lakes Tributary, Paul G. Matson, Gregory L. Boyer, Thomas B. Bridgeman, George S. Bullerjahn, Douglas D. Kane, Robert M.L. Mckay, Katelyn M. Mckindles, Heather A. Raymond, Brenda K. Snyder, Richard P. Stumpf, Timothy W. Davis Dec 2020

Physical Drivers Facilitating A Toxigenic Cyanobacterial Bloom In A Major Great Lakes Tributary, Paul G. Matson, Gregory L. Boyer, Thomas B. Bridgeman, George S. Bullerjahn, Douglas D. Kane, Robert M.L. Mckay, Katelyn M. Mckindles, Heather A. Raymond, Brenda K. Snyder, Richard P. Stumpf, Timothy W. Davis

Great Lakes Institute for Environmental Research Publications

The Maumee River is the primary source for nutrients fueling seasonal Microcystis-dominated blooms in western Lake Erie's open waters though such blooms in the river are infrequent. The river also serves as source water for multiple public water systems and a large food services facility in northwest Ohio. On 20 September 2017, an unprecedented bloom was reported in the Maumee River estuary within the Toledo metropolitan area, which triggered a recreational water advisory. Here we (1) explore physical drivers likely contributing to the bloom's occurrence, and (2) describe the toxin concentration and bacterioplankton taxonomic composition. A historical analysis using 10-years …


Spatial Profiling Of Gangliosides In Mouse Brain By Mass Spectrometry Imaging, Douglas A. Andres, Lyndsay E. A. Young, Matthew S. Gentry, Ramon C. Sun Dec 2020

Spatial Profiling Of Gangliosides In Mouse Brain By Mass Spectrometry Imaging, Douglas A. Andres, Lyndsay E. A. Young, Matthew S. Gentry, Ramon C. Sun

Molecular and Cellular Biochemistry Faculty Publications

No abstract provided.


Finding The Balance​ The Effects Of Α-Cyclodextrin, 2-Hydroxypropyl-Β-Cyclodextrin, And Cholesterol Bacteroides Vulgatus And Clostridium Bolteae​, Bethany Weaver Dec 2020

Finding The Balance​ The Effects Of Α-Cyclodextrin, 2-Hydroxypropyl-Β-Cyclodextrin, And Cholesterol Bacteroides Vulgatus And Clostridium Bolteae​, Bethany Weaver

Pence-Boyce STEM Student Scholarship

Atherosclerosis is a cardiovascular disease that is characterized by the hardening of arteries through the formation of cholesterol plaques. Cyclodextrins could potentially treat atherosclerosis by shrinking plaques. These cyclic oligosaccharides can make complexes with cholesterol but have also shown toxic side effects. This study looked for potential negative effects of cyclodextrins and cholesterol on gut bacteria. It was hypothesized that Bacteroides vulgatus will have decreased growth when grown in broth with cholesterol. In contrast, Clostridium bolteae will have decreased growth when grown in broth with cyclodextrins. Due to the fact that these bacteria are anaerobic, Clostridium bolteae and Bacteroides vulgatus …


The Circadian Clock—A Molecular Tool For Survival In Cyanobacteria, Pyonghwa Kim, Manpreet Kaur, Hye-In Jang, Yongick Kim Dec 2020

The Circadian Clock—A Molecular Tool For Survival In Cyanobacteria, Pyonghwa Kim, Manpreet Kaur, Hye-In Jang, Yongick Kim

Chemistry Faculty Research

Cyanobacteria are photosynthetic organisms that are known to be responsible for oxygenating Earth’s early atmosphere. Having evolved to ensure optimal survival in the periodic light/dark cycle on this planet, their genetic codes are packed with various tools, including a sophisticated biological timekeeping system. Among the cyanobacteria is Synechococcus elongatus PCC 7942, the simplest clock-harboring organism with a powerful genetic tool that enabled the identification of its intricate timekeeping mechanism. The three central oscillator proteins—KaiA, KaiB, and KaiC—drive the 24 h cyclic gene expression rhythm of cyanobacteria, and the “ticking” of the oscillator can be reconstituted inside a test tube just …


Sine Oculis Homeobox Homolog 1 (Six1) Plays A Critical Role In The Progression Of Pulmonary Fibrosis., Cory Wilson Dec 2020

Sine Oculis Homeobox Homolog 1 (Six1) Plays A Critical Role In The Progression Of Pulmonary Fibrosis., Cory Wilson

Dissertations & Theses (Open Access)

Idiopathic pulmonary fibrosis (IPF) is the most common idiopathic interstitial pneumonia with a median survival time of 2-4 years after diagnosis. The alarming mortality rate is due to the lack of effective treatments. IPF is a chronic disease that is characterized by alveolar destruction due to increasing extracellular matrix deposition that leads to poor lung compliance, impaired gas exchange, and ultimately respiratory failure. Repetitive alveolar epithelial injury is a central process to the underlying pathology with injury to the type II alveolar epithelial cells (AT2) specifically being a key player in the pathogenesis of IPF. Recent studies have shown that …


The Effect Of Nuclear Perturbations On The 3d Organization Of The Genome, Rosela Golloshi Dec 2020

The Effect Of Nuclear Perturbations On The 3d Organization Of The Genome, Rosela Golloshi

Doctoral Dissertations

Cells in our body experience constant mechanical forces that influence biological functions such as growth and development. The nucleus has been implicated as a key mechanosensor and can directly influence chromatin organization and epigenetic alterations leading to gene expression changes. However, the mechanism by which such mechanical forces lead to genomic alterations and expression of mechanosensitive genes is not fully understood. The work presented in this dissertation investigates the effect of mechanical and epigenetic perturbations on the 3D genome organization. To investigate this 3D genome folding, we use Chromosome Conformation Capture followed by high throughput sequencing (Hi-C) (Chapter-1) which identifies …


Root Phosphomonoesterase As A Vital Component Of Increasing Phosphorus Availability In Tropical Forests, Kristine Grace Manno Cabugao Dec 2020

Root Phosphomonoesterase As A Vital Component Of Increasing Phosphorus Availability In Tropical Forests, Kristine Grace Manno Cabugao

Doctoral Dissertations

Tropical forests, relative to other terrestrial ecosystems, exchange the largest amount of carbon with the atmosphere and also constitute a significant carbon sink. However, nutrient limitation, particularly of phosphorus (P), could limit growth of tropical forests and their function with the global carbon cycle. Thus, understanding root mechanisms to acquire P is necessary to representing the P cycle and corresponding interactions with plant growth. A large portion of total soil P in tropical forests occurs in organic forms, only accessible through root and microbial production of phosphatase enzymes. These phosphatase enzymes mineralize organic P into orthophosphate, the form of P …


Investigating Transmembrane-Lipid Interactions Of Epha2 And Ph Responsive Peptides, Katherine M. Stefanski Dec 2020

Investigating Transmembrane-Lipid Interactions Of Epha2 And Ph Responsive Peptides, Katherine M. Stefanski

Doctoral Dissertations

Single-pass membrane receptor signaling plays vital roles in human development and maintaining homeostasis. These membrane receptors can also have causative functions in several diseases including cancer. Much is known about the structure and signaling outcomes of these receptors but the mechanistic details of how they pass an extracellular signal across the membrane and into cytoplasm via the transmembrane (TM) domain is unclear. It is further unknown how or if interactions with membrane lipids facilitate and/or regulate these events. Here we use the TYPE7 peptide to target the TM region of a receptor tyrosine kinase, EphA2. EphA2 engages in both tumorigenic …


Population Structure Of A Federally Endangered Plant (Astragalus Jaegerianus Munz, Fabaceae) With Limited Range Using Microsatellites, Sueann Neal Dec 2020

Population Structure Of A Federally Endangered Plant (Astragalus Jaegerianus Munz, Fabaceae) With Limited Range Using Microsatellites, Sueann Neal

Electronic Theses, Projects, and Dissertations

Studies on population genetics examine the relationship and effects of population structure, migration, gene flow and demographic history, and are therefore important in the conservation of endangered species. Astragalus jaegerianus, a critically federally endangered species found in a geographically restricted range is investigated to determine population structure and genetic variation. Previous research on A. jaegerianus focused on DNA sequence data for cpDNA and nrDNA showed no variation. Further research on A. jaegerianus utilizing AFLP’s on the whole genome indicated substantial gene diversity and population structure consistent with geographically widespread species. AFLP research is a cost-effective process to identify levels …


Regulation Of In Vitro And In Vivo Hepatic Stellate Cell Activation By The Ayrl Hydrocarbon Receptor, Shivakumar Rayavara Veerabhadraiah Dec 2020

Regulation Of In Vitro And In Vivo Hepatic Stellate Cell Activation By The Ayrl Hydrocarbon Receptor, Shivakumar Rayavara Veerabhadraiah

Boise State University Theses and Dissertations

Liver fibrosis is a pathological condition characterized by the excessive deposition of extracellular matrix material by activated hepatic stellate cells (HSCs). We recently reported that activation of the aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases HSC activation in vitro and in mouse models of experimental liver fibrosis. The goal of this project was to determine the mechanism by which AhR activation impacts HSC activation and the subsequent development of liver fibrosis. It is possible that HSCs are direct cellular targets for TCDD. Alternatively, TCDD could increase HSC activation indirectly by exacerbating hepatocyte damage …


Identification And Characterization Of Candidate Staphylococcus Aureus Antigens For Inclusion In A Multivalent Bovine Mastitis Vaccine, Danielle Scarbrough Dec 2020

Identification And Characterization Of Candidate Staphylococcus Aureus Antigens For Inclusion In A Multivalent Bovine Mastitis Vaccine, Danielle Scarbrough

Boise State University Theses and Dissertations

Bovine mastitis, inflammation typically caused by bacterial infection, is the most prevalent disease affecting the global dairy industry. Staphylococcus aureus remains one of the most important pathogens implicated in the disease and can persist within herds at subclinical levels. A preventative S. aureus bovine mastitis vaccine would substantially lessen costs associated with treatment and restore revenue lost due to decreased milk production. One such experimental vaccine is the IsdA-CTA2/B + ClfA-CTA2/B vaccine, containing the S. aureus antigens IsdA and ClfA , each fused to the nontoxic A2/B subunits of cholera toxin, which serves as …


The Impact Of Microbial Experience On The Murine Innate Immune Response, Cody Thomas Morrison Dec 2020

The Impact Of Microbial Experience On The Murine Innate Immune Response, Cody Thomas Morrison

Masters Theses

The hygiene hypothesis predicts that certain environmental factors shape overall immune system function in animals and humans. While current specific pathogen free (SPF) mouse models are invaluable for studying the immune system, they have limitations for comparison with humans who have microbial exposures throughout their lifetimes. Several studies have shown that the composition of the immune system of SPF mice more closely resembles that of newborns, whereas the immune system from mice exposed to microbial pathogens more closely reflect adult immunity. In this study we have established a model using traditional SPF mice (“clean mice”) and SPF mice that were …


Iojap: Morphological And Physiological Phenotype Characterization In Arabidopsis, Thomas Jay Payne Dec 2020

Iojap: Morphological And Physiological Phenotype Characterization In Arabidopsis, Thomas Jay Payne

Doctoral Dissertations

IOJAP protein is found in all organisms that contain a ribosome of bacterial origin. The majority of studies suggest that IOJAP plays a role in translation, although this has yet to be thoroughly investigated in plants. Using Arabidopsis thaliana, an extensive phenotype characterization of iojap mutants was performed. Many processes of plant growth were slightly impaired at optimal temperature (22˚C) but became severely hindered at low temperature (12˚C and 4˚C). These cold temperature defects manifested in an overall reduction of plant growth as well as variegation, chlorosis, leaf hyponasty, as well as reduced maximum quantum yield (Fv/F …


Using Second Harmonic Generation To Study Gram-Positive Bacterial Membranes, Lindsey N. Miller Dec 2020

Using Second Harmonic Generation To Study Gram-Positive Bacterial Membranes, Lindsey N. Miller

Doctoral Dissertations

Understanding how small-molecules, such as drugs, interact with bacterial membranes can quickly unravel into much more perplexing questions. No two bacterial species are alike, especially when comparing their membrane compositions which can even be altered by incorporating fatty acids from their surrounding environment into their lipid-membrane composition. To further complicate the comparison, discrete alterations in small-molecule structures can result in vastly different membrane-interaction outcomes, giving rise to the need for more "label-free" studies when analyzing drug mechanisms. The work presented in this dissertation highlights the benefits to using nonlinear spectroscopy and microscopy techniques for probing small-molecule interactions in living bacteria. …


Degree Of Conservation Of Methionines Found To Be Oxidized In The Human Urinary Proteome, Alexis Hall Dec 2020

Degree Of Conservation Of Methionines Found To Be Oxidized In The Human Urinary Proteome, Alexis Hall

Graduate Theses and Dissertations

In previous work from this laboratory, methionine containing peptides from the human urinary proteome were examined by mass spectrometry for the degree of methionine oxidation to the sulfoxide form. While this demonstrated that many of the methionines detected were capable of being oxidized, the question of whether these methionines are important in the structure and/or function of the parent proteins came about. In some proteins, methionine oxidation has been linked to conformational changes and alteration of function and thus can serve as a mechanism for reversible regulation of activity. It is hypothesized that methionines which might serve a regulatory purpose …


Utilizing Earth's Microbiology To Develop The Framework For A Manufactured Martian Nitrogen Cycle, Kyle Valgardson Dec 2020

Utilizing Earth's Microbiology To Develop The Framework For A Manufactured Martian Nitrogen Cycle, Kyle Valgardson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

History has shown us that space travel is a complicated activity not to be taken lightly. Extended missions such as those that would accompany a manned mission to Mars are guaranteed to have increased complexity and require creative solutions to problems we likely take for granted. One such issue is how to supply the necessary amount of nitrogen to the astronauts to keep them alive. Nitrogen is an essential component to life on Earth as most biological molecules, such as protein and DNA, contain a significant amount of it. Most organisms have to get it from what they eat, but …


Functional And Physiological Role Of Extra-Hypothalamic Corticotropin Releasing Hormone Neurons In The Nucleus Of The Hippocampal Commissure In Regulation Of Stress Response, Hakeem Kadhim Dec 2020

Functional And Physiological Role Of Extra-Hypothalamic Corticotropin Releasing Hormone Neurons In The Nucleus Of The Hippocampal Commissure In Regulation Of Stress Response, Hakeem Kadhim

Graduate Theses and Dissertations

Corticotropin releasing hormone (CRH) neurons located within the paraventricular nucleus (PVN) are known to be involved in regulation of stress responses. Recently, CRH neurons were identified above the PVN within the nucleus of the hippocampal commissure (NHpC) that located in the septum. We hypothesized that CRH neurons in the NHpC play a critical role in the stress response due to their rapid activation and could be a part of the traditional hypothalamo-pituitary-adrenal (HPA) axis. The dissertation addresses the role of 1) CRH expressing neurons in the NHpC compared with those within the PVN utilizing two different stressors, food deprivation (FD) …


Rapid Diffusion Observed In Microcrystals By X-Ray Free Electron Laser Mix-And-Inject Serial Crystallography, Tek Narsingh Malla Dec 2020

Rapid Diffusion Observed In Microcrystals By X-Ray Free Electron Laser Mix-And-Inject Serial Crystallography, Tek Narsingh Malla

Theses and Dissertations

With time resolved X-ray crystallography (TRX), it is possible to follow reaction progress in real time. The time resolution is achieved by initiating reaction in crystal prior to X-ray exposure, and then collecting diffraction pattern at different time delays. Time resolved serial femtosecond crystallography (TR-SFX) at X-ray free electron laser (XFELs) allows damage free data collection from microcrystals. Mix-and-inject serial crystallography (MISC) is a type of TR-SFX established at XFELs. In MISC, reaction in enzymatic crystals is triggered by mixing with a substrate, and the resulting structural changes are probed by XFEL pulses.Enzymatic reactions are of great interest due to …


Dissecting Molecular Mechanism Of Heat Stress On Anther Development In Fragaria Vesca, Shikha Malik Dec 2020

Dissecting Molecular Mechanism Of Heat Stress On Anther Development In Fragaria Vesca, Shikha Malik

Theses and Dissertations

Strawberry is an important fruit crop in the Rosaceae family. Originally from the temperate region, strawberry is vulnerable to heat waves, which reduce fruit yield and quality. Previous studies have shown that heat stress impairs pollen development; however, the molecular mechanisms by which heat stress affects the development of anthers, where pollen develops, are unclear. Due to the genome complexity of cultivated strawberry (Fragaria × ananassa, 2n = 8x= 56), Fragaria vesca (2n = 2x = 14) was used, which emerges as a diploid model plant for Rosaceae, to study the effects of heat stress on anther development at morphological …


A Mechanistic Investigation Of Cytochrome C Nitrite Reductase Catalyzed Reduction Of Nitrite To Ammonia: The Search For Catalytic Intermediates, Shahid Shahid Dec 2020

A Mechanistic Investigation Of Cytochrome C Nitrite Reductase Catalyzed Reduction Of Nitrite To Ammonia: The Search For Catalytic Intermediates, Shahid Shahid

Theses and Dissertations

Cytochrome c Nitrite Reductase (ccNiR) is a periplasmic homodimeric decaheme enzyme that catalyzes the reduction of nitrite to ammonium in a process that involves six electrons and eight protons. Under standard assay conditions, which use a strong reducing agent as an electron source, catalysis takes place rapidly without producing detectable intermediates. However, intermediates do accumulate when weaker reducing agents are employed, allowing the ccNiR mechanism to be studied. Herein, the early stages of Shewanella oneidensis ccNiR-catalyzed nitrite reduction were investigated in isolation by using the weak reducing agents N,N,N’,N’-tetramethyl-p-phenylenediamine (TMPD) and the 2-electron reduced form of indigo trisulfonate. Experiments were …


P53 Drives A Transcriptional Program That Elicits A Non-Cell-Autonomous Response And Alters Cell State In Vivo, Sydney Moyer Dec 2020

P53 Drives A Transcriptional Program That Elicits A Non-Cell-Autonomous Response And Alters Cell State In Vivo, Sydney Moyer

Dissertations & Theses (Open Access)

Cell stress and DNA damage activate the tumor suppressor p53, triggering transcriptional activation of a myriad of target genes. The molecular, morphological, and physiological consequences of this activation remain poorly understood in vivo. We activated a p53 transcriptional program in mice by deletion of Mdm2, a gene which encodes the major p53 inhibitor. By overlaying tissue-specific RNA-sequencing data from pancreas, small intestine, ovary, kidney, and heart with existing p53 ChIP-sequencing, we identified a large repertoire of tissue-specific p53 genes and a common p53 transcriptional signature of seven genes which included Mdm2 but not p21. Global p53 activation …


Implications Of Lysine Acetylation On The Enzymes Of The Tca Cycle, Sumana Venkat Dec 2020

Implications Of Lysine Acetylation On The Enzymes Of The Tca Cycle, Sumana Venkat

Graduate Theses and Dissertations

The tricarboxylic acid (TCA) cycle is a central route for the energy production via oxidative phosphorylation and is ubiquitous throughout nature. Apart from playing a major role in energy provision, it is also essential for a wide range of physiological functions in any organism. Although an increasing emphasis is laid on the interlinking role of the cycle, its regulation and control are less very less understood. As the field progresses, the consequences of TCA cycle anomalies are shown to be tied to various cancers and other disorders. The matter becomes more complex when considering the varying functions of the isozymes …