Biochemistry Commons^™

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 …

Validation Of Anti-Oxidative Stress Genes From Genome-Wide Screening Of Escherichia Coli, Carson Ercanbrack

Chemistry & Biochemistry Undergraduate Honors Theses

The primary purpose of this project is to evaluate the genes that play a role in the oxidative stress response in Escherichia coli. In doing so, the entire genome of E. coli was subject to throughput in which individual genes were determined to have a role in the bacteria’s oxidative stress response. Moreover, this project focused on the validation of the genes that were able to pass the initial throughput stage. The genes were subject to two forms of validation. In the first validation technique, candidate genes were overexpressed and minimum inhibitory concentrations of hypochlorous acid were taken. Following, a …

Antibacterial And Antioxidant Potential Of A Novel Plant, Eriodictyon Californicum, And Its Healing Abilities, Allie Richards

Undergraduate Theses

Our body is under constant attack of oxidative stress (OS). OS is a crucial factor in the pathogenesis and progression of various chronic diseases such as diabetics, rheumatoid arthritis, myocardial infarction, cardiovascular diseases, stroke, cancer, Alzheimer’s disease, Parkinson’s disease, aging and more. The main cause of OS is free radicals, which are continuously generated in our body during normal metabolic processes. These free radicals have the potential to damage any of our key biomolecules. To protect ourselves from the toxic effect of free radicals the human body has a built-in army of antioxidants that play an important role in the …

Understanding Cytochrome C Maturation In Anaerobic Archaea, Blake Wojciechowski

Biological Sciences Undergraduate Honors Theses

Methanoperedens nitroreducens (MPEBLZ), an archaeal methanotroph and close relative of Methanosarcina acetivorans, contain numerous cytochrome c proteins. However, difficulty in using these organisms as a model for cytochrome cresearch has created a pressure to express cytochrome c proteins in an organism that is much easier to work with. A punitive cytochrome c protein (MPEBLZ_04274) from M. nitroreducens was attempted to be cloned into a model methanogen M. acetivorans as well as Escherichia coli. Cytochrome c proteins are important for many metabolic processes within anaerobic archaea. In order for a mature cytochrome c to be formed heme must …

Computational Analysis Of Oxidative Stress In Endothelial Dysfunction: Insights On The Role Of Tetrahydrobiopterin, Ascorbate And Glutathione, Sheetal Kedar Panday

Wayne State University Dissertations

Oxidative stress and endothelial dysfunction are reported in the cardiovascular and neurovascular diseases. Oxidative stress is caused due to an increase in the generation of reactive oxygen (ROS) and nitrogen species (RNS) and incapacity of antioxidant systems to eliminate ROS and RNS. Endothelial dysfunction is characterized by a reduction in nitric oxide (NO) bioavailability. NO is constitutively produced by enzyme endothelial nitric oxide synthase (eNOS). A reduction in tetrahydrobiopterin (BH4), which is an essential cofactor of eNOS, can lead to eNOS uncoupling. There is complex interplay between the ROS/RNS and antioxidant system underlying pathophysiologies of vascular diseases, however our quantitative …

Amelioration Of Alzheimer's Disease Pathology In 12-Month-Old Happ(Sweind) Transgenic Mice After Treatment With A Cysteine Rich Whey Supplement, Immunocal®, Srivalli Puttagunta

Electronic Theses and Dissertations

Deficits in Reelin expression and signaling play a pathogenic role in Alzheimer’s disease (AD). Thus, strategies aimed at correcting Reelin deficits may provide a novel therapeutic approach to treating AD. The cysteine-rich, whey protein supplement, Immunocal®, has recently been shown to rescue Reelin expression in a mouse model of Schizophrenia. Given that Reelin-expressing neurons of the entorhinal cortex region are a highly vulnerable population of cells that are lost early in AD, we examined the effects of Immunocal® in the hippocampal-entorhinal cortex formation in a mouse model of AD. Glutathione levels and Reelin expression in the hippocampal-entorhinal cortex formation (entorhinal …

Naturally Derived Compounds As Preventatives Of Proteinopathies, Lois Mendez

Open Access Theses & Dissertations

Neurodegenerative diseases, such as Parkinson’s disease (PD), afflict millions worldwide. Of greater concern is the fact that a main risk factor this disease is aging and the baby boomer population is now reaching a geriatric age. Despite the active research in this area, little progress has been made in the development of therapeutic strategies and furthering of our understanding in pinpointing the causal events that onset these disease processes. Our lab has focused on studying the protein homeostasis of key biomarkers in neurodegenerative diseases and examining whether natural compounds can act as neuro-protectants and, thus, attenuate the pathology that ensues …

Characterizing The Activity Of Antimicrobial Peptides Against The Pathogenic Bacterium Clostridium Difficile In An Anaerobic Environment, Adenrele Mojeed Oludiran

Chemistry & Biochemistry Theses & Dissertations

Clostridium difficile is an anaerobic Gram-positive pathogen with high treatment costs and mortality and very high antibiotic tolerance. Antimicrobial host-defense peptides (HDPs) produced naturally by animal immune systems are promising candidates to develop novel therapies for bacterial infection because they cause oxidative stress that damages multiple targets in bacterial cells, so it is difficult for bacteria to evolve resistance to these attacks.

Piscidins, fish-derived HDPs that can also form complexes with copper (Cu) to enhance their activities, are very active against multiple bacterial species in an aerobic environment. We examined their activity against C. difficile and other species in an …

Elucidating The Interplay Between Sodium Selenite On The Tick Amblyomma Maculatum Selenoprotein Gene Expression, Afnan M. Beauti

Honors Theses

Selenium (Se) is an element recognized as an essential micronutrient in eukaryote organisms. Selenoproteins contain selenium as selenocysteine, the 21st amino acid. Selenium plays a role in cell growth and functioning. At low concentrations, it can induce growth and at high concentrations, it can cause a cell to stop growing and potentially have toxic effects on the cell and organism. When selenium levels are high, oxidative stress results by the production of reactive oxidative species. Selenoproteins, however, can aid the antioxidant response in the cell. Ticks are arthropods of interest, as they are one of few that contain many selenogenes, …

Parkin Misfolding, Dysfunction, And Degradation In Parkinson's Disease, Alexander S. Mccarton

Electronic Thesis and Dissertation Repository

Mutations in the gene encoding parkin (PARK2) result in familial early onset forms of Parkinson’s disease (PD) based on the loss of parkin’s E3 ubiquitin ligase function. Protein misfolding is a common molecular feature of most neurodegenerative diseases, including PD. To test whether parkin misfolding also plays a role in the more common spontaneous PD, we established and functionally characterized a parkin yeast model. We found that oxidative and protein folding stress, parkin point mutations and truncations, and parkin’s interaction with the PD-associated kinase PINK1 profoundly alter parkin’s subcellular localization and toxicity. Notably, these conditions also induce parkin fragmentation, degradation, …

Genetic Variation In Long-Term And Short-Term Physiological Changes In Daphnia Magna During Acclimation To High Temperature, Bret L. Coggins

Undergraduate Honors Theses

The aquatic zooplankton crustacean Daphnia magna must be able to tolerate thermal stress in order to survive their native shallow ponds that are susceptible to drastic seasonal and diurnal temperature fluctuations as well as to globally increasing temperatures. Survival in such variable environments requires plastic responses that must include fundamental aspects of Daphnia biochemistry and physiology. Adaptive response to selection favoring such plastic phenotypes requires the presence of genetic variation for plastic response in natural populations. Adverse effects of elevated temperature on aquatic organisms are diverse and so are their plastic responses; among the most severe challenges aquatic organisms face …

Nitric Oxide Synthase Activity And Its Modulation In The Treatment Of Colorectal Cancer, Asim Alam

Theses and Dissertations

The American Cancer Society estimates more than 141,000 new cases of and about 50,000 deaths from colorectal cancer every year. Treatment options include surgery, radiation therapy and targeted therapies such as anti-angiogenics. However, no therapies address the key driving factor of colorectal cancer: inflammation. It is well known that chronic inflammatory conditions such as Crohn’s Disease, ulcerative colitis, diabetes, obesity and cigarette smoking all elevate the risk of developing colorectal cancer. One of the hallmarks of chronic inflammation is the elevated levels of reactive oxygen/nitrogen species (ROS/RNS). A primary source of these ROS/RNS is uncoupled Nitric Oxide Synthase (NOS). Under …

Mechanistics Of Prothymosin Alpha And Nrf2 In The Keap1-Nrf2 Mediated Oxidative Stress Response, Halema Khan

Electronic Thesis and Dissertation Repository

In an effort to dissect the mechanism of interaction of IDPs, in this thesis we focus on Prothymosin a (ProTa) and nuclear factor erythroid 2-related factor 2 (Nrf2), intrinsically disordered proteins, in the Nrf2 mediated oxidative stress response. Kelch-like ECH-associated protein 1 (Keap1) is an inhibitor of Nrf2, a key transcription factor of cytoprotective genes. Under unstressed conditions, Keap1 interacts with Nrf2 in the cytoplasm via its Kelch domain and suppresses Nrf2 activity. During oxidative stress, Nrf2 is released from Keap1 and is shuttled to the nucleus, where it initiates pro cell survival gene transcription. ProTa also interacts with the …

Increase Of Basal Oxidative Stress Levels And Impairment Of Heme Oxygenase-1/Biliverdin Reductase Post-Translational Modification By The Defect Of Parkinson-Related Gene Of Pink1, Zhaoshu Zhang

Theses and Dissertations--Chemistry

Parkinson disease (PD) is the most common movement disorder and the second most common neurodegenerative disease. PINK1, PTEN-induced kinase 1, functions as a serine/threonine kinase as well as a protector of mitochondrial function. Mutations in PINK1 gene result in either mitochondria dysfunction or disruption of kinase signaling pathways involved in the pathogenesis of PD.

In this thesis, oxidative stress levels were examined in the brain of PINK1 knockout mice, and also how heme oxygenase-1 and biliverdin reductase are affected in brain of PINK1 knockout mice. In addition, posttranslational modifications are a way to control the behavior of proteins, so posttranslational …

Biochemical And Cellular Mechanisms Of Retina And Retinal Pigment Epithelium Apoptosis, Srinivasa Rao Sripathi

Dissertations, Master's Theses and Master's Reports - Open

Oxidative stress, intense light exposure and oxygen imbalances such as hypoxic or hyperoxic conditions perturb mitochondria, nuclear function and further lead to cellular damage of retina and retinal pigment epithelial (RPE) cells. Our major aim is to understand the various biochemical and proteomic events that occur during the progression of retina and RPE cell death. The comprehensive objectives of this dissertation are to understand the functional aspects of protein expression, posttranslational modifications, protein or lipid binding changes, phenotypic, morphological alterations and their regulation during the retina and RPE apoptosis under oxidative stress. The entire study is divided into four chapters …

The Contribution Of Oxidative Stress In The Protein Damage And Dna Lesion In Alzheimer's Disease Neuropathology, Cheng Zhang

Doctoral Dissertations

Glutathione (GSH) plays an essential role in the intracellular antioxidant defense against the oxidant radicals, especially the ·OH radical. To understand the early and progressive cellular changes in Alzheimer's disease (AD) development, we investigated reduced glutathione/oxidized glutathione (GSH/GSSG) status in a double mutated AD transgenic mouse model (B6.Cg-Tg), which carries Swedish amyloid precursor protein mutation (APPswe) and exon 9 deletion of the PSEN1 gene. Likewise, S-glutathionylation (Pr-SSG) is a specific post-translational modification (PTM) of cysteine residues by the addition of glutathione. S-glutathionylated proteins induced by oxidative stress play an essential role in understanding the pathogenesis of the aging …

Investigations Into Modulation Of Brain Oxidative Stress By Various Interventions, Jessica Lynn Harris

Theses and Dissertations--Chemistry

In this thesis study we examined glycogen synthase kinase-3β (GSK-3β) and its effects over Nrf2 and Pin 1 as it relates to Alzheimer’s disease (AD). AD is a neurodegenerative disease characterized by a prolonged high oxidative environment. Transcription factor Nrf2 is vital in the brain’s defense against oxidative insults through its up-regulation of over 100 antioxidants. Depletion of the brain’s antioxidant defense system results in intolerance to an oxidative environment, contributing to the progression of AD. The regulatory Pin 1 protein promotes cellular homeostasis, and when down-regulated results in increased deposits of neurofibrillary tangles (NFTs) and amyloid-β (Aβ) plaques, the …

The Role Of Protein Kinase C Epsilon In Hydrogen Peroxide And Nitric Oxide Release During Oxidative Stress Caused By Extracorporeal Shockwave Lithotripsy, Edward S. Iames

PCOM Biomedical Studies Student Scholarship

Clinical extracorporeal shock wave lithotripsy (ESWL) treatment to ablate kidney stones can cause acute damage to the renal microvasculature. Accumulation of continued treatment with shockwave therapy can lead to chronic damage to the kidney, and lead to clinical hypertension. Shockwaves have been shown to stimulate endothelial cells to release superoxide (SO), which is converted to hydrogen peroxide (H₂O₂), and reacts with nitric oxide (NO) to produce peroxynitrite anion (OONO^-), creating a powerful oxidant that increases oxidative stress while simultaneously reducing NO bioavailability. Increased oxidative stress during events such as ESWL, also uncouples NO production …

In Vivo Oxidative Stress In Alzheimer Disease Brain And A Mouse Model Thereof: Effects Of Lipid Asymmetry And The Single Methionine Residue Of Amyloid-Β Peptide, Miranda Lu Bader Lange

University of Kentucky Doctoral Dissertations

Studies presented in this dissertation were conducted to gain more insight into the role of phospholipid asymmetry and amyloid-β (Aβ)-induced oxidative stress in brain of subjects with amnestic mild cognitive impairment (aMCI) and Alzheimer disease (AD). AD is a largely sporadic, age-associated neurodegenerative disorder clinically characterized by the vast, progressive loss of memory and cognition commonly in populations over the age of ~65 years, with the exception of those with familial AD, which develop AD symptoms as early as ~30 years-old. Neuropathologically, both AD and FAD can be characterized by synapse and neuronal cell loss in conjunction with accumulation of …