Biochemistry Commons^™

Dlipin-A Link Between Lipid Metabolism, Glucose Homeostasis And Growth In Drosophila Melanogaster, Sandra Schmitt

Graduate Theses and Dissertations

Lipins are a family of highly conserved proteins found from yeasts to humans. Lipins have dual functions, serving as phosphatidate phosphatase enzymes (PAP) in the synthesis of neutral fats (triacylglycerols, TAG) and as transcriptional co-regulators that affect the expression of genes involved in lipid and fatty acid metabolism. Thus, they play central roles in metabolic control. Disruption of Lipin function has been implicated in lipodystrophy, obesity and insulin resistance. Using dLipin, the Drosophila homolog of Lipin, as a model, I aimed to elucidate the relationship between the two biochemical functions of Lipin and metabolic homeostasis. I discovered there is a …

Granulins As Inflammatory Mediators In Alzheimer Disease, Randi G. Reed

Honors Theses

Alzheimer disease (AD) is a neurodegenerative disorder characterized by severe memory deficit and cognitive decline among the elderly. This degeneration is caused by the aggregation and deposition of a protein called amyloid-β (Aβ) in the brain. Aggregation of Aβ causes neuroinflammation in addition to other toxic events. However, it is unclear whether inflammation from an external source, such as from a traumatic brain injury (TBI), could trigger Aβ aggregation. In this context, several pro-inflammatory mediators such as cytokines and chemokines have been suspects. It is now hypothesized that a group of proteins called granulins (Grns) are unique inflammatory mediators that …

Role Of C-Kit In The Growth, Migration And Differentiation Of Human Cardiac Progenitor Cells., Bathri Narayan Vajravelu

Electronic Theses and Dissertations

The belief that adult mammalian heart lacks regenerative potential was challenged by the identification of c-kit positive cardiac progenitor cells (CPCs) in the heart. A recent phase I clinical trial (SCIPIO), has shown that autologous c-kit positive CPCs improve cardiac function and quality of life when transplanted into ischemic heart disease patients. c-Kit is a type III receptor tyrosine kinase and a common stem cell antigen. Stem cell factor (SCF) is the only known ligand for c-kit. Although c-kit is extensively used as an invariable marker of resident CPCs and shown to be important in the context of different cell …

Assessment Of Variation In Susceptibility Of The Fall Armyworm, Spodoptera Frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), To Bacillus Thuringiensis Toxins, Karen Ferreira Da Silva

Department of Entomology: Dissertations, Theses, and Student Research

The fall armyworm, Spodoptera frugiperda, is a polyphagous insect pest affecting multiple crops. Fall armyworm is managed with insecticides and corn hybrids expressing insecticidal proteins derived from Bacillus thuringiensis. The early detection of insect resistance is important for making appropriate management decisions informs IPM and IRM recommendations.

The objective of the first study was to establish baseline susceptibility of fall armyworm populations to the Cry1F Bt insecticidal protein, emphasizing collections from locations where fall armyworm overwinters in the U.S. Fall armyworm neonates were exposed to artificial diet treated with increasing Cry1F concentrations, and mortality and growth inhibition were …

Investigations Into The Molecular Mechanisms Of Bacterial Pathogen–Host Interactions: Construction Of A Dual Plasmid System For Incorporation Of Unnatural Amino Acids Into Pseudomonas Syringae Pv. Tomato Dc3000, Scotty D. Raber

Department of Chemistry: Dissertations, Theses, and Student Research

A dual plasmid system for the incorporation of unnatural amino acids into plant pathogen, Pseudomonas syringae pv. tomato DC3000, has been designed. This invention is expected to allow (a) mutations of proteins synthesized by the bacterium, P. syringae pv. tomato DC3000, that can capture molecular targets, especially for such modified proteins secreted by the phytopathogen into the host plant cells of A. thaliana and S. lycopersicum, (b) expression of biological probes in the bacterial species to monitor changes in redox, nutritional, and other small molecule states over pre-, post- and in situ disease stages, and secretion of such biological …

Dna Methylation In Lung Tissues Of Mouse Offspring Exposed In Utero To Polycyclic Aromatic Hydrocarbons, Trevor J. Fish

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Polycyclic aromatic hydrocarbons (PAHs) comprise an important class of environmental pollutants that are known to cause lung cancer in animals and suspected lung carcinogens in humans. PAHs are also known to cause cancer in offspring when provided to a pregnant mouse. Some evidence from cell-based studies points to PAHs as modulators of the epigenome, that is modifications to DNA structure that control the expression of genes. Inappropriate changes to the epigenome and consequently expression of cancer-critical genes are often characteristic of cancer cells. The objective of this thesis research was to determine the impact of transplacental exposure to two model …

Dna Polymerase Θ (Polq) And The Cellular Defense Against Dna Damage, Matthew J. Yousefzadeh

Dissertations and Theses (Open Access)

In mammalian cells, DNA polymerase θ (POLQ) is an unusual specialized DNA polymerase whose in vivo function is under active investigation. The protein is comprised of an N-terminal helicase-like domain, a C-terminal DNA polymerase domain, and a large central domain that spans between the two. This arrangement is also found in the Drosophila Mus308 protein, which helps confer resistance to DNA interstrand crosslinking agents. Homologs of POLQ and Mus308 are found in eukaryotes, including plants, but a comparison of phenotypes suggests that not all of these genes are functional orthologs. Flies with defective Mus308 are sensitive to DNA interstrand crosslinking …

Selection Methods For Genetically-Modified T Cells: In Support Of Translational Therapy, David Rushworth

Dissertations and Theses (Open Access)

T cells are blood cells which organize the immune system of the host. These cells are necessary for the host to respond appropriately to threats from foreign organisms and cancerous growth. However, in the case of certain infections and cancer, T cells are unable to respond appropriately to a threat and establish immunity. This leads to disease when the infection or cancer is not sufficiently eliminated. On the other hand, T cells can lack tolerance for healthy tissue and perceive healthy tissue as infected. The ensuing over-reactive immune response also leads to disease. A delicate balance must exist between immunity …

Regulation Of Cell Adhesion By The Ferm Proteins, Ptpn14 And Merlin, Patty Dimarco Hewitt

Dissertations and Theses (Open Access)

Cell-cell adhesion is critical for the control of tissue organization and homeostasis. A family of proteins that regulate cell-cell adhesions is the FERM (4.1 protein, Ezrin, Radixin, Moesin) domain-containing proteins.One FERM domain protein, the non-receptor tyrosine phosphatase PTPN14, is mutated or deleted in several human cancers suggesting that it may be involved in tumor development and/or progression. Additionally, the loss of the FERM domain protein Merlin is associated with tumor development and metastasis.Both PTPN14 and Merlin have been shown to localize and possibly regulate adherens junction (AJ) functions. This work sought to determine if …

Development, Validation, And Application Of Analytical Methods For Characterizing Adsorbed Protein Orientation, Conformation, And Bioactivity, Aby Thyparambil

All Dissertations

The structure and bioactivity of adsorbed proteins are tightly interrelated and play a key role in their interaction with the surrounding environment. These factors are of critical importance in many biotechnological applications. However, because the bioactive state of an adsorbed protein is a function of the orientation, conformation, and accessibility of its bioactive site(s), the isolated determination of just one or two of these factors will typically not be sufficient to understand the structure-function relationships of the adsorbed layer. Rather a combination of methods is needed to address each of these factors in a synergistic manner to provide a complementary …

Phosphotransacetylase And Xylulose 5-Phosphate/Fructose 6-Phosphate Phosphoketolase: Two Eukaryotic Partners Of Acetate Kinase, Tonya Taylor

All Dissertations

Although acetate is a predominant metabolite produced by many eukaryotic microbes, far less attention has been given to acetate metabolism in eukaryotes than in bacteria and archaea. Acetate kinase (Ack), which catalyzes the reversible phosphorylation of acetate from ATP, is a key enzyme in bacterial acetate metabolism. Ack primarily partners with phosphotransacetylase (Pta), which catalyzes the generation of acetyl phosphate from acetyl-CoA, but can also partner with xylulose 5-phosphate/fructose 6-phosphate phosphoketolase (Xfp), which produces acetyl phosphate from either xylulose 5-phosphate or fructose 6-phosphate. The Ack-Pta pathway, found primarily in bacteria, is also present in lower eukaryotes such as the green …

Beryllium Is A Potent And Unique Gsk-3Β Inhibitor With Potential To Differentially Regulate Glycogen Synthase And Β-Catenin, Ata Ur Rahman Mohammed Abdul

UNLV Theses, Dissertations, Professional Papers, and Capstones

Glycogen Synthase Kinase-3β (GSK-3β) is an important serine/threonine kinase that phosphorylates/regulates diverse and metabolically important proteins. Some of the important substrates of GSK-3β are glycogen synthase, tau, β-catenin, cyclin D1, axin, c-jun, c-myc, Heat Shock Factor–1, BCL-3, CREB, Histone H1.5, mdm2, p21 (CIP1), pyruvate dehydrogenase and many more. De-regulation of GSK-3β has been implicated in diseases like cancer, Alzheimer’s disease, bipolar disorder and type 2 diabetes mellitus. Currently, GSK-3β is one of the most widely studied proteins and there is a great interest in developing potent and efficient GSK-3β-inhibitors for research as well as therapeutic purposes. We demonstrate that beryllium …

Microbial-Derived Oils And Value-Added Products: Biosynthesis And Applications For Biofuel Production, Alex T. Mccurdy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Efforts are being made to replace petroleum-derived fuels with biofuels in a cost competitive manner. It is apparent that the continued use of petroleum is futile as population and technological growth put increasing pressure on the demand for cheap energy and chemicals. Diminishing resources, civil unrest in the Middle East, and the impact of using petrochemicals on the environment are critical driving forces for research in generating renewable petroleum replacements that can be produced with a limited carbon-footprint. Today, biofuels are derived mostly from land-based plants, but their potential for displacing petroleum is limited due to the competition with available …

Synthesis And Characterization Of Carbonized Poly (Divinylbenzene) Microspheres For Carbon/Nanodiamond/Polymer-Based Core-Shell Materials And Applications Of This Mixed-Mode Phase To High-Performance Liquid Chromatography, Chuan-Hsi Hung

Theses and Dissertations

This work focuses on improving the quality of carbon-based core-shell materials for high performance liquid chromatography (HPLC) via the characterization of the core materials, and also the development of chromatographic methods (separations) for them. In the early part of this work, I applied organic synthesis to make uniform, spherical poly(divinylbenzene) (PDVB) microspheres, and then carbonized them to prepare carbon core materials for core-shell particle synthesis. Here, I studied in detail the surface and material properties of these particles with multiple instruments, which allowed me to describe the physical and chemical changes that took place during each treatment. The uniform, spherical …

Recyclable Organocatalysis Of One-Pot Michael/Mannich/Lactamization Sequence For Asymmetric Synthesis Of Fluorinated Poly-Substituted 2-Piperidinones, Anthony P. Tran

Honors College Theses

2-piperidinone (δ-lactam), a bio-interesting nitrogen-containing six-membered ring compound, has attracted much interest from researchers both in synthetic and medicinal chemistry. Polysubstituted piperidine derivatives, such as the δ-lactam, serve as a synthon for numerous biologically relevant structures and pharmaceutical agents. A novel one-pot asymmetric Michael/Mannich/Lactamization sequence promoted by recyclable fluorous bifunctional cinchona alkaloid–thiourea organocatalysts is introduced for the synthesis of polysubstituted 2-piperidinones bearing four contiguous stereocenters, one of which is a fluorinated quaternary chiral center with excellent stereoselectivities (ee up to >99%, dr up to >20:1).

Inducing And Characterizing M2c Macrophages At A Non-Degradable Implant In Vivo, Geoffrey David Keeler

Graduate Theses and Dissertations

The implantation of biomaterials in the body leads to a reaction known as the foreign body response (FBR) which leads to the eventual encapsulation of the biomaterial. This encapsulation proves to be detrimental to certain biomaterials, such as implanted glucose sensors, which rely on interacting with the extracellular space for proper function. Altering the FBR has become of interest in an effort to increase the longevity and integration of biomaterials. One strategy for altering the FBR is by targeting the macrophage, shown to play an important role in the FBR. In this work, the microdialysis sampling technique was used to …

Local Modulation And Measurement Of Macrophage-Derived Bioactive Proteins From Implanted Biomaterials In Rat, Geetika Bajpai

Graduate Theses and Dissertations

Fibrosis around the implanted medical devices is a severe problem that can plague long-term device reliability. Activation of macrophage phenotype (macrophage polarization) has emerged as a new and possible means for reducing fibrosis in the fields of biomaterials and regenerative medicine. Macrophages are phagocytic cells that respond to microenvironmental cues that direct their phenotype. Macrophage activation has been widely studied in mouse and human in the context of tumor biology, yet little information is available regarding how macrophage activation could be used in a biomaterials context. Further, rats rather than mice are the common subjects in biomaterials experiments. A significant …

Binding Interactions Of (R)- And (S)-Hydroxypropyl-Com Dehydrogenases And The Zinc Knuckle Proteins Air1 And Air2, Jeremy W. Bakelar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A thorough understanding of protein function requires knowledge of how proteins interact with their substrates and with other proteins. The work entailed in this dissertation describes the binding interactions of proteins from two different model systems: (1) the dehydrogenase enzymes R- and S-HPCDH and (2) the zinc knuckle proteins Air1 and Air2.

R- and S-HPCDH are highly similar enzymes (42% identical) that function in a unique metabolic pathway found in the soil bacterium Xanthobacter autotrophicus. The bacterium produces R- and S-HPCDH simultaneously to facilitate the transformation of two different forms of the organic …

Whole Genome Comparison Of A Large Collection Of Mycobacteriophages Reveals A Continuum Of Phage Genetic Diversity, Welkin H. Pope, Charles A. Bowman, Daniel A. Russell, Deborah Jacobs-Sera, David J. Asai, Steven G. Cresawn, William R. Jacobs Jr, Roger W. Hendrix, Jeffrey G. Lawrence, Graham F. Hatfull, Dr. Kathleen Cornely

Chemistry & Biochemistry Faculty Publications

The bacteriophage population is large, dynamic, ancient, and genetically diverse. Limited genomic information shows that phage genomes are mosaic, and the genetic architecture of phage populations remains ill-defined. To understand the population structure of phages infecting a single host strain, we isolated, sequenced, and compared 627 phages of Mycobacterium smegmatis. Their genetic diversity is considerable, and there are 28 distinct genomic types (clusters) with related nucleotide sequences. However, amino acid sequence comparisons show pervasive genomic mosaicism, and quantification of inter-cluster and intra-cluster relatedness reveals a continuum of genetic diversity, albeit with uneven representation of different phages. Furthermore, rarefaction analysis shows …

Repsa-Directed Identification Of Dna-Binding Specificity For Orphan Transcription Factors, Kamir Hiam

Symposium of Student Scholars

The function of many genes and the biological roles of their encoded products are still not well characterized. Given the sequence-specific DNA-binding properties of transcription factor proteins, it is possible to purify them, identify the responsible polypeptide(s), determine their consensus binding sequences, and identify their genomic binding sites. Thus, one can go from cellular extract to proposed biological regulatory roles in relatively short order. Our goal is to identify and characterize orphan DNA-binding proteins in the model organism E. coli K12 using the novel combinatorial technique, REPSA (Restriction Endonuclease Protection Selection Amplification), as well as further develop the REPSA to …