Biochemistry, Biophysics, and Structural Biology Commons^™

Role Of Secondary Interactions (Π, Agostic) As Well As Solvent Influence On Alkali Metal Complexes, Elizabeth D. Nagle

Renée Crown University Honors Thesis Projects - All

We here attempt to synthesize heterobimetallic alkali metal complexes with bulky phenolate ligands via solid state direct metallation. The solid state route may offer a facile method of producing these heterobimetallic species. Synthesis of heterobimetallic alkali metal compounds remains a challenge, as the homometallic complexes are generally favored over formation of the heterobimetallic species. Previous work has shown that the alkali metals have a strong solvent dependency; the recrystallization of heterobimetallic products from toluene yields the heterobimetallic, while recrystallization from THF yields the homometallic. However, the ability for phenolate ligands to stabilize metal centers through secondary interactions, such as M∙∙∙π …

Understanding The Genetic And Molecular Mechanisms Of The Shl3 Phenotype In Arabidopsis Thaliana, Sukeerti Kesar

Renée Crown University Honors Thesis Projects - All

The study of plant genetics and the molecular mechanisms regulating plant-pathogen interactions is an intensely studied area of research in molecular genetics. Gaining an understanding of the defense mechanisms of plants has proven highly useful in the construction of transgenic plants for increased crop yield. The focus of my research was on the defense mechanisms of Arabidopsis thaliana, a plant in the mustard family. Several features of Arabidopsis make it an excellent model plant for molecular genetic studies. A few of these include a short life cycle (approximately 8 weeks), a completely sequenced genome, high fecundity, and the availability …

The Role Of A2b Adenosine Receptor Signaling In Adenosine Dependent Lung Disease, Yang Zhou

Dissertations and Theses (Open Access)

Chronic lung diseases and acute lung injuries are two distinctive pulmonary disorders that result in significant morbidity and mortality. Adenosine is a signaling nucleoside generated in response to injury and can serve both protective and destructive functions in tissues and cells through interaction with four G-protein coupled adenosine receptors: A1R, A2AR, A2BR, and A3R. However, the relationship between these factors is poorly understood. Recent findings suggest the A2BR has been implicated in the regulation of both chronic lung disease and acute lung injury. The work presented in this dissertation utilized the adenosine deaminase-deficient mouse model and the bleomycin-induced pulmonary injury …

Carboxylases Involved In Microbial Acetone And Acetophenone Metabolism, Ameya Mashruwala

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

A number of bacteria are capable of growth with acetone and acetophenone as their sole sources of carbon and/or energy. The pathways and enzymes involved in the transformation of these molecules into useable carbon and energy are unique. Among these are two novel enzymes, acetone carboxylase and acetophenone carboxylase, which represent a fundamentally novel classes of carboxylases.

The initial step in acetone metabolism, in X. autotrophicus st Py2, R. capsulatus st B10 and R. rhodochrous, is the thermodynamically unfavorable reaction to yield acetoacetate. This step is catalyzed by the enzyme acetone carboxylase and is coupled with the unprecedented, concomitant hydrolysis …

Glycopeptidome Of A Heavily N-Glycosylated Cell Surface Glycoprotein Of Dictyostelium Implicated In Cell Adhesion, Christa L. Feasley, Jennifer M. Johnson, Christopher M. West, Catherine P. Chia

School of Biological Sciences: Faculty Publications

Genetic analysis has implicated the cell surface glycoprotein gp130 in cell interactions of the social amoeba Dictyostelium, and information about the utilization of the 18 N-glycosylation sequons present in gp130 is needed to identify critical molecular determinants of its activity. Various glycomics strategies, including mass spectrometry of native and derivatized glycans, monosaccharide analysis, exoglycosidase digestion, and antibody binding, were applied to characterize a nonanchored version secreted from Dictyostelium. s-gp130 is modified by a predominant Man8GlcNAc4 species containing bisecting and intersecting GlcNAc residues and additional high-mannose N-glycans substituted with sulfate, methyl-phosphate, and/or core R3-fucose. Site mapping confirmed the occupancy …

The Development Of A Comprehensive Mechanism For Intracellular Calcium Oscillations: A Theoretical Approach And An Experimental Validation, Amanda A. Borges, Deanna Salter, Sandor Kadar, Steven B. Symington

Pell Scholars and Senior Theses

Calcium is an important second messenger for cellular communication. Theoretical models help scientists understand its signalling mechanism. A comprehensive model was developed in order to minimize any limitations in the models currently presented in the literature. Experimental results support the model and therefore the theoretical model provides a plausible explanation of the dynamics of the calcium-signaling mechanism. In the future, additional verification will be performed using various experimental configurations on PC12 cells. Further, the model will be used to predict the response of cells to environmental factors such as pesticides and heavy metals.

Bacillus Cereus And Bacillus Anthracis Germination Kinetics: A Michaelis-Menten Approach, Helen Luu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bacillus species are rod-shaped, gram-positive bacteria that are capable of producing endospores. In this dormant stage, the endospores can persist in hostile physical and chemical environments. Once conditions become favorable, the spores germinate into actively dividing cells, vegetative cells. Germination is a crucial step for the pathogenicity of the Bacilli in affecting a host organism.

Our study applies mathematical approaches to spore germination to determine whether the binding of one germinant will affect the binding of another germinant. We pursued this approach with two different species, B. cereus and B. anthracis, both pathogenic organisms. B. cereus is a widely known …

Xenoestrogen-Specific Mechanisms Of Developmental Reprogramming Correlate With Gene Expression And Tumor Development, Kristen L. Greathouse

Dissertations and Theses (Open Access)

Environmental exposures during sensitive windows of development can reprogram normal physiological responses and alter disease susceptibility later in life in a process known as developmental reprogramming. We have shown that neonatal exposure to the xenoestrogen diethylstilbestrol (DES) can developmentally reprogram the reproductive tract in genetically susceptible Eker rats giving rise to complete penetrance of uterine leiomyoma. Based on this, we hypothesized that xenoestrogens, including genistein (GEN) and bisphenol A (BPA), reprogram estrogen-responsive gene expression in the myometrium and promote the development of uterine leiomyoma. We proposed the mechanism that is responsible for the developmental reprogramming of gene expression was through …

Preeclampsia, Autoimmunity And The At1 Receptor, Roxanna A. Irani

Dissertations and Theses (Open Access)

Preeclampsia (PE) is a disease of late pregnancy characterized by maternal hypertension and proteinuria. It is associated with preterm delivery and significant perinatal morbidity and mortality. Despite affecting ~7% of first pregnancies, there is no effective screening method to identify women at risk, nor is there a definitive treatment other than delivery of the baby and placenta. Though the pathogenesis of PE remains unclear, an imbalance in the renin-angiotensin and immune systems are thought to be major contributors. Bridging these two concepts, it has recently been shown that women with PE harbor specific autoantibodies: the angiotensin II type 1 receptor …

A New Tumor Suppressor Gene Candidate Regulated By The Non-Coding Rna Pca3 In Human Prostate Cancer, Alessandro K. Lee

Dissertations and Theses (Open Access)

Prostate cancer is the second leading cause of cancer-related death and the most common non-skin cancer in men in the USA. Considerable advancements in the practice of medicine have allowed a significant improvement in the diagnosis and treatment of this disease and, in recent years, both incidence and mortality rates have been slightly declining. However, it is still estimated that 1 man in 6 will be diagnosed with prostate cancer during his lifetime, and 1 man in 35 will die of the disease.

In order to identify novel strategies and effective therapeutic approaches in the fight against prostate cancer, it …

Host-Pathogen Interactions Of Secreted And Surface Staphylococcus Aureus Factors, Vanessa Vazquez

Dissertations and Theses (Open Access)

Staphylococcus aureus is an opportunistic bacterial pathogen that can infect humans and other species. It utilizes an arsenal of virulence factors to cause disease, including secreted and cell wall anchored factors. Secreted toxins attack host cells, and pore-forming toxins destroy target cells by causing cell lysis. S. aureus uses cell-surface adhesins to attach to host molecules thereby facilitating host colonization. The Microbial Surface Components Recognizing Adhesive Matrix Molecules (MSCRAMMs) are a family of cell-wall anchored proteins that target molecules like fibronectin and fibrinogen. The Serine-aspartate repeat (Sdr) proteins are a subset of staphylococcal MSCRAMMs that share similar domain organization. Interestingly, …

Ampa Receptor Allosterism: Measurement Of The Conformational Changes In The Ligand Binding Domain Of A Functional Receptor, Jennifer Gonzalez-Mcgehee

Dissertations and Theses (Open Access)

Ionotropic glutamate receptors are important excitatory neurotransmitter receptors in the mammalian central nervous system that have been implicated in a number of neuropathologies such as epilepsy, ischemia, and amyotrophic lateral sclerosis. Glutamate binding to an extracellular ligand binding domain initiates a series of structural changes that leads to the formation of a cation selective transmembrane channel, which consequently closes due to desensitization of the receptor. The crystal structures of the AMPA subtype of the glutamate receptor have been particularly useful in providing initial insight into the conformational changes in the ligand binding domain; however, these structures are limited by crystallographic …

Developmental Changes In The Structure And Composition Of The Postsynaptic Density, Matthew T. Swulius

Dissertations and Theses (Open Access)

The development of the brain and its underlying circuitry is dependent on the formation of trillions of chemical synapses, which are highly specialized contacts that regulate the flow of information from one neuron to the next. It is through these synaptic connections that neurons wire together into networks capable of performing specific tasks, and activity-dependent changes in their structural and physiological state is one way that the brain is thought to adapt and store information. At the ultrastructural level, developmental and activity-dependent changes in the size and shape of dendritic spines have been well documented, and it is widely believed …

The Ubiquitin Ligase Ube4b Is Required For Efficient Epidermal Growth Factor Receptor Degradation, Natalie Sirisaengtaksin

Dissertations and Theses (Open Access)

The length of time that integral membrane proteins reside on the plasma membrane is regulated by endocytosis, a process that can inactivate these proteins by removing them from the membrane and may ultimately result in their degradation. Proteins are internalized and pass through multiple distinct intracellular compartments where targeting decisions determine their fate. Membrane proteins initially enter early endosomes, and subsequently late endosomes/multivesicular bodies (MVBs), before being degraded in the lysosome. The MVB is a subset of late endosomes characterized by the appearance of small vesicles in its luminal compartment. These vesicles contain cargo proteins sorted from the limiting membrane …

Antimicrobial Activity Of D-Lenolate®, Andy Phui

UNLV Theses, Dissertations, Professional Papers, and Capstones

Olive trees are one of the most important fruit trees in the Mediterranean. Although not validated by research, olive leaves are traditionally believed to fight off fever and infections. It has been shown that olive leaf extracts possess antimicrobial activity. Olive leaf extracts contain polyphenols. One of the major phenolic compounds is oleuropein. Oleuropein and other polyphenols have been shown to exhibit antimicrobial activity. East Park Research (EPR) developed an extraction process that they claim does not alter the chemical composition of the olive leaves. The extract is known by the commercial name d-lenolate®. Studies have provided evidence that d-lenolate®, …

Investigation Of Biochemistry And Enzymology Of Acyl-Coenzyme A Synthetase, Yu Meng

All Dissertations

Acetyl-CoA, an essential metabolite at the junction of various anabolic and catabolic pathways, is generated both from the breakdown of carbohydrates, lipids, and amino acids, and from the activation of acetate. AMP-forming acetyl-CoA synthetase, a key enzyme for acetate activation into acetyl-CoA in all domains of life, is a member of the adenylate-forming enzyme superfamily. Although members in the superfamily have different biological functions, they all share the property of forming an acyl-adenylate intermediate. Here I describe my research on characterization of a medium-chain acyl-CoA synthetase from Methanosarcina acetivorans (Macs_Ma) and identification of key residues in acyl substrate …

Genetic And Biochemical Studies Of Plasmid Pir52-1 In Lactobacillus Helveticus, Cody Alexander Tramp

Undergraduate Honors Capstone Projects

Lactobacillus helveticus is a species of lactic acid bacteria. These bacteria, which produce lactic acid as a major product of carbohydrate metabolism, are used industrially to produce cheese and other fermented dairy products (Ebringer et al., 2008). Many species of lactic acid bacteria also possess probiotic characteristics and when ingested potentially confer increased immune function, regulate gut microbiota, and improve digestion in the host (Reid, 2008). Genetic studies of these probiotic effects and other characteristics of L. helveticus and related species have been hindered by the lack of stably replicating plasmid vectors. Plasmid vectors for several Lactobacillus species have been …

A Guide To The Continuing Investigation Of The Relationship Between The Cytoskeleton And Cell Wall In Developing Buds Of Physcomitrella Patens, Derek Brockman

Senior Honors Projects

Persistent questions in biology address the nature of tissue organization and how information encoded in the genome can be manifested as a physical form. While the ‘final’ product of gene expression is a protein, science has yet to elucidate how those proteins are able to interact with other cellular components and external forces to generate a specific cell shape. This complex process is critical in determining not only the shape of an individual cell but also that of an entire organ. In plants, cell shape is controlled by cellulose microfibrils of the cell wall, which are typically oriented perpendicular to …

High-Throughput Screening Studies Of Inhibition Of Human Carbonic Anhydrase Ii And Bacterial Flagella Antimicrobial Activity, Albert A. Barrese Iii

Dissertations

Complete abstract attached as supplemental file.

Physiological And Molecular Function Of Hap3b In Flowering Time Regulation And Cold Stress Response, Mingxiang Liang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Heme-activated proteins (HAPs) are transcription factors that have multiple roles in plant growth and development, such as embryogenesis, flowering time control, and drought tolerance.

In the present study I found that HAP3b was also involved in controlling response to cold stress. Transcript profiling and gene expression analyses indicated that HAP3b repressed the CBF3 regulon under normal growth conditions. As a result, plants with HAP3b-overexpressed showed decreased survival rates while plants homozygous for the null allele hap3b showed an improved freezing tolerance compared to wild-type plants.

To understand the mechanism of HAP3b in Arabidopsis, i.e. whether it also acts …