Biochemistry, Biophysics, and Structural Biology Commons^™

Impact Of Conformational Change, Solvation Environment, And Post-Translational Modification On Desulfurization Enzyme 2'-Hydroxybiphenyl-2-Sulfinate Desulfinase (Dszb) Stability And Activity, Landon C. Mills

Theses and Dissertations--Chemical and Materials Engineering

Naturally occurring enzymatic pathways enable highly specific, rapid thiophenic sulfur cleavage occurring at ambient temperature and pressure, which may be harnessed for the desulfurization of petroleum-based fuel. One pathway found in bacteria is a four-step catabolic pathway (the 4S pathway) converting dibenzothiophene (DBT), a common crude oil contaminant, into 2-hydroxybiphenyl (HBP) without disrupting the carbon-carbon bonds. 2’-Hydroxybiphenyl-2-sulfinate desulfinase (DszB), the rate-limiting enzyme in the enzyme cascade, is capable of selectively cleaving carbon-sulfur bonds. Accordingly, understanding the molecular mechanisms of DszB activity may enable development of the cascade as industrial biotechnology. Based on crystallographic evidence, we hypothesized that DszB …

Illuminating Dna Packaging In Sperm Chromatin: How Polycation Lengths, Underprotamination And Disulfide Linkages Alters Dna Condensation And Stability, Daniel Kirchhoff

Theses and Dissertations--Chemistry

During spermiogenesis, somatic chromatin is remodeled and a vast majority (> 90%) of DNA histones are replaced by short arginine-rich peptides called protamines. This compaction is immense, with protamine-DNA self-assembly in sperm chromatin resulting in a final volume roughly 1/6th of a somatic nucleus. This near crystalline organization of the DNA in sperm is thought crucial both for the transport of the paternal genes as well as for the protection of genetic information as sperm chromatin is transcriptionally inactive and all DNA repair mechanisms are shut down.

Chapter 1 will include an overview of the topics discussed in this document, …

Detection Of Beta-Lactamase Variants In Municipal Wastewater And Fresh Water, Sunil Pandey

Masters Theses

The occurrence and spread of antibiotic-resistant genes (ARGs) are pressing public health problems worldwide. A key factor contributing to the spread of ARGs is lateral gene transfer. Wastewater treatment plants (WWTPs) are measured hot spots of microbial diversity and resistance because they receive polluted wastewater from diverse sources and contain a variety of different environments with dense bacterial loads. Due to the overuse of antibiotics the genetic capacities of microbes have profited. This helps every source of resistance gene and every means of horizontal gene transmission to develop the multiple mechanism of resistance to each antibiotic used clinically, agriculturally, or …

Functions Of Dfrp And Other Drg Pathway Genes In The Moss Physcomitrella Patens, Robert James Srygler

Graduate Research Theses & Dissertations

GTP binding proteins (G proteins) are molecular switches that regulate many aspects of physiology in all cells. DRG1 and DRG2 (Developmentally Regulated GTP-binding proteins) have been found in all eukaryotes examined. Amino acid identity across eukaryotes is about 65% within an orthologous group and 55% between paralogs of a single species. Although DRGs are likely involved in some aspect of translation regulation, details of their precise cellular functions are not known.

In addition to DRGs there are other genes/proteins that comprise the “DRG pathway.” DFRPs (DRG Family Regulatory Proteins) have been shown to physically and genetically interact with DRGs. Previous …

Multi-Scale Computational Studies Of Calcium (Ca2+) Signaling, Bin Sun

Theses and Dissertations--Chemistry

Ca²⁺ is an important messenger that affects almost all cellular processes. Ca²⁺ signaling involves events that happen at various time-scales such as Ca²⁺ diffusion, trans-membrane Ca²⁺ transport and Ca²⁺-mediated protein-protein interactions. In this work, we utilized multi-scale computational methods to quantitatively characterize Ca²⁺ diffusion efficiency, Ca²⁺ binding thermodynamics and molecular bases of Ca²⁺-dependent protein-protein interaction. Specifically, we studied 1) the electrokinetic transport of Ca²⁺ in confined sub-µm geometry with complicated surfacial properties. We characterized the effective diffusion constant of Ca²⁺ in a cell-like environment, which helps to understand …

Xylan Metabolism By Caulobacter Crescentus, Viet Bui

Masters Theses

Bacteria present unique opportunities to explore the molecular mechanisms of nutrient acquisition processes at single cell level under various experimental conditions. Caulobacter crescentus is a gram-negative oligotrophic environmental bacterium with adaptive physiological responses, such as slow growth or complete arrest of cell cycle, presence of sessile and motile progenies with the sessile cells growing stalk to enhance nutrient uptake for growth in low-nutrient conditions. Details of plant polysaccharide-derived carbon compound, such as cellobiose, maltose, and xylose utilization by C. crescentus can be found but molecular details or mechanisms of polysaccharide utilization, such as xylan, has not been reported. Database analyses …

Mllt3 Regulates Expression Of Genes Critical To Liver Metabolic Homeostasis, Jonathan Richard Dixit

Master's Theses

Hepatic steatosis (fatty liver) is increasingly prevalent in the US, and is characterized by triglyceride accumulation within hepatocytes. This is a direct result of an imbalance between lipid import, export, de novo lipogenesis, and beta oxidation. Hepatic steatosis can also progress to nonalcoholic steatohepatitis (NASH) which is characterized by increased hepatocyte damage, inflammation, and fibrosis. Further progression can lead to liver failure or hepatocellular carcinoma, requiring liver transplant or causing death. Our lab recently created Mllt3 conditional whole body knockout mice. These mice developed hepatic steatosis and NASH following Mllt3 deletion. MLLT3 is a master gene regulator that is part …

Structural Characterization Of Black Widow Spider Dragline Silk Proteins Crp1 And Crp4, Mikayla Shanafelt

University of the Pacific Theses and Dissertations

Spider dragline silk is a biomaterial with outstanding material properties, possessing high-tensile strength and toughness. In nature, dragline silk serves a central role during spider locomotion and web construction. Today, scientists are racing to elucidate the molecular machinery governing silk extrusion, attempting to translate this knowledge into a mimicry process in the laboratory to create synthetic fibers for a wide range of different applications. During extrusion, it has been established that biochemical and mechanical forces govern spidroin folding, aggregation, and assembly. In black widow spiders, at least 7 different proteins have been identified as constituents of dragline silk fibers. These …

Development Of A Biomarker Panel For Identifying Stressed Marine Mammals, Laura Pujade

University of the Pacific Theses and Dissertations

Increasing anthropogenic disturbance in marine ecosystems such as fishing, oil-drilling, and noise pollution can have detrimental effects on the reproduction and survival of apex predators such as marine mammals. Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, resulting in increased circulating glucocorticoid (GCs) hormones, which alter expression of target genes encoding metabolic enzymes and other mediators of stress. Prolonged HPA axis stimulation may increase catabolism of nutrient stores and suppress immune and reproductive functions, impacting the fitness of marine mammals. GCs measurements are used to identify wild animals experiencing stress. However, these measurements may not be sensitive enough to distinguish between an …

Evaluating Methods Of Obtaining Male Pheromone From Hymenochirus Sp. Using Analytical Chemistry, Vincent Wing-Kun Leung

University of the Pacific Theses and Dissertations

Male Hymenochirus sp. frogs are known to release pheromone that attracts females of the same species. Four methods for collecting secretions containing pheromone in Hymenochirus sp. were tested: norepinephrine injection, gonadotropin-releasing hormone injection, homogenization of gland tissue, and electrostimulation of the skin over the breeding gland area. The samples collected were analyzed using high-performance liquid chromatography (HPLC) and mass spectrometry. The HPLC chromatograph for the male norepinephrine sample contained a peak at 6.4 min that was not in the female norepinephrine sample HPLC chromatograph. The male norepinephrine sample mass spectrum had a peak of m/z 292.0 not in the female …

Investigating The Effect Of Rutaecarpine On The Benzo[A]Pyrene-Induced Dna Damage In Vitro, You Li

University of the Pacific Theses and Dissertations

Benzo[a]pyrene (BaP), is one of the most potent mutagens and carcinogens known. It requires metabolic activation through cytochrome P450 (CYP)1A1 to yield the ultimate carcinogenic metabolite, benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE). BPDE can bind to DNA and form predominantly covalent (+) trans adducts at the N2 position of guanine causing DNA damage. Rutaecarpine (RTC) is an herbal medicine that has been used to treat several diseases such as headache, hypertension, gastrointestinal disorders, amenorrhea, and anti-inflammation. It has also been reported as a potent inducer of CYP enzymes, including CYP1A1, and CYP1A2. The mechanisms underlying up-regulation of CYP1A1 by RTC is dependent on aryl …

Assessing The Effects Of Antioxidants On Oxidative Stress In Triple-Negative Breast Cancer Cells Via Protein Carbonylation, Dalton Sheffield

Honors Theses

Breast cancer is a highly complex, heterogeneous disease, and potential effective treatment options are being continuously researched in order to provide a method of halting cancer growth and metastasis. One area in particular involves alleviating oxidative stress within cancer cells. Oxidative stress is generally defined as an imbalance between oxidant and antioxidant species in favor of the oxidants. Cancer cells use this oxidative stress to initiate carcinogenesis in cells through different mechanisms, and protein carbonylation is a primary biomarker used to quantify oxidative stress levels. Antioxidant compounds are those used to alleviate oxidative stress within cells. Here breast cancer cells …

Protein Templated Silver Nanoclusters, Greyson Keel

Honors Theses

Nanoclusters are smaller than their nanoparticle counterparts and have unique properties. Most research has been done on gold nanoclusters, but silver nanoclusters are said to be more robust. During the process of trying to create nanoclusters, several methods in the procedure were changed when gathering data: determining a successful silver concentration, working with the correct buffer, mixing gold and silver metals together, observing the effects of pH, and finding a good reducing agent. After experimenting with those changes, a successful protocol was adapted and modified from literature (Journal of Materials Chemistry, 2011, 21, 11205-11212) to produce the protein-templated Ag clusters. …

Benchmark Structures And Harmonic Vibrational Frequencies Of Hydrated Halide Ions: X– (H2o)N, X = F, Cl, Br, And I (Where N = 1 – 4), Caroline Anne Rader

Honors Theses

This study extends our efforts to generate benchmark structures and harmonic vi- brational frequencies from neutral hydrogen bonded clusters to solvated ions. The analytical gradients and Hessians developed for the N-body:Many-body integrated QM:QM method facilitate the computation of benchmark-quality properties near the CCSD(T) complete basis set limit. In this work, a series of solvated halide ion sys- tems (X−(H2O)n clusters, where X = F, Cl, Br and I and n = 1 to 4) is being characterized with the MP2 and 2-body:Many-body CCSD(T):MP2 (2b:Mb) meth- ods. For n ≥ 2, the latter technique uses the high-level CCSD(T) method to evaluate …

Time- And Ph- Dependent Proteolysis Of Engineered Proteins By Collagenase, Hunter Berry

Honors Theses

Pleiotropic effects from oral administration of anti-inflammatory drugs limit their effectiveness. The ultimate goal of this project is to develop a novel self-assembling protein-based hydrogel for in situ delivery of NSAIDs at the site of chronic inflammation. Since inflammation causes acidification and activation of collagenases in the inflamed tissue, we have designed the hydrogel to respond to both of these queues to effectively deliver drug at the site. Self-assembly of the protein hydrogel exploits the high affinity and specific interaction between the protein calmodulin (CaM) and its specific binding peptide, M13. The two components of the hydrogel, CCLP and PCLP …

Lost In Translation: Challenges And Solutions To Language Barriers In Healthcare In Mississippi, Galina Ostrovsky

Honors Theses

Language barriers can impede access to healthcare and compromise quality of care for limited English proficiency (LEP) patients. Although a rights-based framework would suggest and federal mandates require healthcare facilities to provide language access services, multiple factors result in the persistence of language barriers in healthcare. As the literature review shows, these factors include limitations in policy, enforcement, standardization, resources, and ability to recruit and retain professional interpreters. This thesis uses a multi-method case study entailing Mississippi in general and information from two specific sites, a rural Delta county and an urban central county, to assess the issue of language …

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 …

Computational Study Of Disease Related Proteins Form Electrostatic Point Of View, Chitra Bahadur Karki

Open Access Theses & Dissertations

In the last three decades, many giant DNA viruses have been discovered. The giant viruses present a unique and essential research frontier for the study of self-assembly and regulation of supramolecular assemblies. The question on how these giant DNA viruses assemble thousands of proteins so accurately to form their protein shell, the capsids, remains largely unanswered. Revealing the mechanisms of giant virus assembly will help to discover the mysteries of many self-assembly biology problems. Paramecium Bursaria Chlorella Virus 1 (PBCV-1) is one of the most intensively studied giant viruses. Based on the high-resolution structure of PBCV-1, we implemented a multi-scale …

Novel Methods For The Inactivation Of Cruzain For The Prevention And Treatment Of Chagas Disease, Veronica Gonzalez

Open Access Theses & Dissertations

Chagas Disease, also known as American Trypanosomiasis, is endemic to Latin American and is gradually making its way to other countries. The disease is caused by Trypanosoma cruzi, a protozoan parasite that causes lesions and inflammation of organs including the heart, esophagus, and colon. Over 30% of people infected will develop heart disease which can be fatal if untreated. While no vaccine is yet available, research is currently being conducted in finding new treatments for the disease. One target is an enzyme that is believed to help the progression of the disease. Cruzain, a cysteine protease expressed as a pro-enzyme, …

Non Linear Optics For Materials Fabrication And Medical Instrumentation, Aurelio Paez

Open Access Theses & Dissertations

Two-photon absorption is a nonlinear optical process where two photons are absorbed by a molecule simultaneously. The probability of this quantum phenomenon is proportional to the quadratic excitation of light intensity. It has many applications in biomedical and materials research, such as two-photon fluorescence microcopy. The first project is to apply two-photon absorption induced bond cleavage in photoreactive materials for engineering 3D tissue scaffolds. The major challenge for growing thick 3D tissues is the lack of vasculature, where nutrients and oxygen can be delivered to the growing cells. Our collaborators have synthesized a novel polypeptide that is composed of 34-mer …