Life Sciences Commons^™

The Impact Of A Non-Ionic Adjuvant To The Persistence Of Pesticides On Produce Surfaces, Daniel Barnes

Masters Theses

Adjuvants can enhance the performance of the pesticide active ingredients in many ways including decreasing surface tension and reducing evaporation. Understanding how adjuvants effect pesticide behavior (e.g., surface persistence) is crucial for developing effective pesticide formulations, as well as facilitating the development of effective approaches to reduce pesticide residues from the surface of fresh produce post-harvest. The objective of this study is to investigate the effect of a non-ionic surfactant, Surf-Ac 910, on the persistence of two model pesticides, thiabendazole and phosmet on apple surfaces. The result shows that the addition of Surf-Ac 910 increased both the maximum wetted area …

Caulobacter Clpxp Adaptor Popa’S Domain Interactions In The Adaptor Hierarchy Of Ctra Degradation, Thomas P. Scudder

Masters Theses

The degradation and recycling of protein is a process essential for the maintenance and regulation of cellular function. More specifically, in Caulobacter crescentus, the ClpXP protease is responsible for driving progression through the cell cycle and protein quality control. This protease utilizes three known adaptors to selectively degrade proteins that initiate different stages of development. This thesis will elaborate on the specific binding interface on one of these adaptors, PopA, with another, RcdA, and focus in on specific residues on PopA and investigate their roles in adaptor binding and delivery of CtrA, the master regulator of Caulobacter. Finally, I …

Combining Simulation And The Mspa Nanopore To Study P53 Dynamics And Interactions, Samantha A. Schultz

Masters Theses

p53 is a transcription factor and an important tumor suppressor protein that becomes activated due to DNA damage. Because of its role as a tumor suppressor, mutations in the gene that encodes it are found in over 50% of human cancers. The N-terminal transactivation domain (NTAD) of p53 is intrinsically disordered and modulates the function and interactions of p53 in the cell. Its disordered structure allows it to be controlled closely by post-translation modifications that regulate p53’s ability to bind DNA and interact with regulatory binding partners. p53 is an attractive target for developing cancer therapeutics, but its intrinsically disordered …

Characterization Of Arabidopsis Eukaryotic Translation Initiation Factor 2Α (Eif2Α) Mutants, Mark Edens

Masters Theses

Plants are stationary organisms that are charged with overcoming a multitude of biotic and abiotic stresses. The eukaryotic translation initiation factor 2 (eIF2) is responsible for charging the P-site of the forming 80S ribosome with the initiator methionyl-tRNA. Thus, eIF2 is a protein of utmost consequence in the growth and development of organisms. The eIF2 protein is also a mediator of global translational regulation in the eukaryotic integrated stress response (ISR), where the α-subunit is phosphorylated by protein kinases, such as the kinase GCN2. Here, five eIF2α allele mutants in Arabidopsis were found to be deleterious to plant growth, development, …

The Application Of Microbial Source Tracking To Aid In Site Prioritization For Remediation In Lower Michigan, John J. Hart

Masters Theses

Non-point source fecal pollution is a threat to both the environment and public health. Climate change, aging infrastructure, and intensified agricultural practices are predicted to accentuate this issue. In Michigan, due to the high instance of aging infrastructure and intensified agriculture, non-point source fecal pollution has caused many waterbodies to exceed the state standards posing a risk to recreational activities and source water. Due to this threat, there is an increased effort to identify and remediate these sources. My study focused on improving the identification of non-point source fecal pollution through a combination of culture-based and molecular fecal indicator bacteria …

Characterization Of The Poly (Adp-Ribose) Polymerase Family In The Fusarium Oxysporum Species Complex, Daniel Norment

Masters Theses

Fusarium oxysporum is a filamentous fungus that is known to invade over a hundred different hosts and poses a major threat to the economy and food supply world-wide. Poly (Adenosine diphosphate-Ribose) Polymerase (PARP) is a family of regulatory proteins that affect change in the cell through transfer of ADP-Ribose moieties onto target molecules. The most well-studied PARP protein is the human PARP1, a PARylating nuclear protein that serves as our model PARP protein. F. oxysporum was found to contain a large expansion of PARP catalytic-domain-containing proteins compared to other filamentous fungi. We utilized in silico multiple sequence alignments and domain …

Screening For Binding Partners And Protein-Protein Interactions Of A Fungal Transcription Factor- Xdr1, Nishadi Punsara Gallala Gamage

Masters Theses

Clarireedia spp. (formerly Sclerotinia homoeocarpaF.T. Bennett) is the causal agent dollar spot, the most economically important turfgrass disease impacting golf courses in North America. The most effective strategy for dollar spot control is repeated application of multiple classes of fungicides. However, reliance on chemical application has led to resistance to four classes of fungicides as well as multidrug resistance (MDR). Fungi are known to detoxify xenobiotics, like fungicides, through transcriptional regulation of three detoxification phases: modification, conjugation and secretion. Little is known, however, of the protein-protein interactions that facilitate these pathways. Following next-generation RNA sequencing of Clarireedia spp., a …

The Flavoprotein Rcla Is A Hypothiocyanous Acid Reductase, Irina Chapman

Masters Theses

Reactive chlorine species (RCS) - hypochlorous acid (HOCl), hypothiocyanous acid (HOSCN), and chloramines - are powerful antimicrobial oxidants generated by the innate immune system. Bacteria developed defense mechanisms against RCS, which are highly toxic for invading pathogens. One such defense system involves RclA, an enzyme from the flavin disulfide reductase family, which is massively upregulated upon exposure of Escherichia coli to RCS. Recent research suggests that RclA functions as a Cu(II) reductase to provide resistance against RCS. However, the exact mechanism used by RclA was subject to debate. In this study, we demonstrate that RclA is unlikely to function as …

Influence Of Physical Variability Of Highly Weathered Sedimentary Rock On Nitrate In Area 3 Of The Enigma Field Research Site At Y-12, Erin Kelly

Masters Theses

Uranium processing and waste storage in unlined waste ponds leached contaminants into the groundwater at Y-12, Oak Ridge, Tennessee, from the 1950s to 1980s. Groundwater wells near the S-3 ponds have had the highest nitrate concentrations of groundwater anywhere in the world (>10,000 mg/L). For reference, the maximum contaminant level for nitrate in drinking water set by the U.S. Environmental Protection Agency is 10 mg/L. Since 2012, the ENIGMA (Ecosystems and Networks Integrated with Genes and Molecular Assemblies) group has been characterizing, monitoring, and conducting field experiments to understand the interactions between contaminants, microbes, and the subsurface. The goals …

Hsp70 Phosphorylation: A Case Study Of Serine Residues 385 And 400, Sashrika Saini

Masters Theses

Molecular chaperones play a key role in maintaining a healthy cellular proteome by performing protein quality control. Heat shock protein 70s (Hsp70s) are a diverse class of evolutionarily conserved chaperones that interact with short hydrophobic sequences presented in unfolded proteins, promoting productive folding, and preventing proteins from aggregation. Most of the extensive research on chaperone examines mechanism, substrate promiscuity, and engagement with many co-chaperones. Only recently were chaperones recognized to be frequent targets of post-translational modifications (PTMs). Despite the recent rise in PTMs identified, the impact of these modifications on chaperone function, whether singular or in concert with other modifications, …

Exploring Knockdown Phenotypes And Interactions Between Atad3 Proteins In Arabidopsis Thaliana, Eli S. Gordon

Masters Theses

Mitochondria are required for a diverse array of cellular functions and processes. ATAD3 (ATPase family AAA domain containing protein 3) proteins are newly discovered mitochondrial membrane proteins in Arabidopsis thaliana. Homologous to ATAD3A in metazoans, Co-Immunoprecipitation/Mass spectrometry and genomic analysis identified a four ATAD3A homologues in A. thaliana. The four A. thaliana proteins are referred to as ATAD3A1 (At3g03060), ATAD3A2 (At5g16930), ATAD3B1 (At2g18330), and ATAD3B2 (At4g36580). Studies in metazoans indicate that ATAD3A localizes to Mitochondria-ER contact sites and is involved in a variety of processes required for proper mitochondrial function, but ATAD3A proteins are poorly defined in plants. …

Link Between Muscle And Whole-Body Energetic Responses To Exercise, Christopher M.T. Hayden

Masters Theses

Substantial evidence exists regarding how skeletal muscles use energy and how this affects muscular performance. What remains unclear is how characteristics of muscle energetics affect whole-body energetics during daily living, and what effects this may have on mobility. The goal of this study was to determine the associations between muscle and whole-body energetics including the relationships between: 1) muscle PCr depletion (∆PCr) in response to light intensity isotonic contractions and the oxygen deficit at the onset of a 30-min treadmill walk (30MTW), and, 2) muscle oxidative capacity and excess post-exercise oxygen consumption (EPOC; 30MTW), respiratory exchange ratio (RER; 30MTW), and …

Investigating Structural Proteins By Light Scattering, Uma Nudurupati

Masters Theses

This thesis evaluates the organization of the structural proteins, Human Gamma D crystallin and Collagen type II, into higher-order structures using light scattering. Specifically, it evaluates the natures of incipient aggregation in Human Gamma D crystallin and the nature of its interactions with CAPEGn, an electrostatic blocker. Additionally, this thesis evaluates whether Collagen type II growth kinetics follows Classical nucleation theory.

Development Of Fluorescence Microscopy Approaches To Study Subcellular Protein Transport And Enzymatic Activity, Anchal Singh

Masters Theses

Understanding the subcellular localization of proteins and their activity is important in understanding their normal function in eukaryotic cells. Fluorescence cellular imaging techniques can selectively and sensitively visualize subcellular biochemistry. Using this approach, two different methods were employed in this thesis. The first focused on studying protein import into peroxisome and the other on monitoring the activity of an endoplasmic reticulum (ER)-localized enzyme, human carboxylesterase 1 (CES1).

Peroxisomes are mainly known as the center for long chain fatty acid b-oxidation as well as the production and detoxification of hydrogen peroxide. Proteins which are needed in the peroxisomes are encoded in …

Xylan-Derived Carbon Nutrient Acquisition By Caulobacter Crescentus, Rhoda Ekuama Inkoom

Masters Theses

Bacterial decomposition of xylan and uptake of xylan-derived carbon compounds require a combination of enzymes, proteins, and complex molecular mechanisms. Bacteria have evolved molecular mechanisms for its utilization depending on its environment and source of xylan. Caulobacter crescentus, a Gram-negative bacterium which lives in an aquatic oligotrophic environment, exhibits asymmetric division which is an adaptive feature for its nutrient poor habitat. Although aromatic hydrocarbon and cellulose-derived mono-, di- and oligosaccharide utilization has been reported in literature, its xylan-derived carbon compound utilization is yet to be characterized. In this study, C. crescentus utilizes xylan-derived monomers arabinose, xylose and acetate as …

Investigation Of Shot1-Binding Atpases In Arabidopsis Thaliana, Sam Zelman

Masters Theses

Mitochondria play critical roles not only in primary metabolism as a central organelle for ATP generation, but also in responding to abiotic stresses. We identified a mutation in the MTERF18 (Mitochondrial Transcription Termination factor)/SHOT1 (Suppressor of hot1-4 1) gene in Arabidopsis thaliana that enables plants to better tolerate heat and oxidative stresses, presumably due to reduced oxidative damage, but the exact molecular mechanism of the heat tolerance is unknown. In order to reveal the stress tolerance mechanisms of mterf18/shot1 mutations, it is critical to understand the molecular defects of the mutant and to identify …

Assessing Stress Tolerance Of Organelle Small Heat Shock Protein Mutants In Arabidopsis Thaliana, Parth Patel

Masters Theses

Molecular chaperones are proteins found in virtually every organism and are essential to cell survival. When plants are heat stressed, they upregulate and downregulate multiple genes, many of which are associated with the heat shock response. Small heat shock proteins (sHSPs) are one class of molecular chaperones that are upregulated during heat shock. They are proposed to act as the first line of defense by binding to heat sensitive proteins and preventing their irreversible aggregation. However, many details of sHSP function remain to be discovered and exactly what proteins they protect is unresolved. In addition to cytosolic sHSPs found in …

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 …

Lmea, A Conserved Cell-Envelope Protein In Mycobacteria, Is Important For Antibiotic Resistance And Cell Envelope Permeability, Sarah Hassan Osman

Masters Theses

The cell envelope of mycobacteria is critical for the survival and virulence of pathogenic species during infection, and its biosynthesis has been a proven drug target. Therefore, finding new targets in the biosynthetic pathway of cell envelope components is of great interest. Mycobacterium smegmatis is a model organism for the study of the devastating pathogen Mycobacterium tuberculosis. Previously, lipomannan elongation factor A (LmeA) has been identified as a cell envelope protein that is critical for the control of mannan chain length of lipomannan (LM) and lipoarabinomannan (LAM), lipoglycan components of the cell envelope. The deletion mutant, ∆lmeA, accumulates abnormal LM/LAM …

Investigation Of Glutamate Carboxypeptidase Ii Roles In The Folate Cycle Dependent Reproduction And Development Of Caenorhabditis Elegans, Jessica M. Derham

Masters Theses

Glutamate Carboxypeptidase II (GCPII) is a transmembrane, zinc metallopeptidase that is expressed in a wide range of organisms, including roundworms, mice, and humans. In humans, GCPII is primarily expressed in the prostate, kidneys, small intestine, and central nervous system. Within the small intestine, the expected function of GCPII is to aid in the absorption of dietary folate from the intestinal lumen. GCPII cleaves excess glutamates from folate to yield monoglutamated folate which is then readily transported into the enterocyte. Folate can then be used through the one carbon metabolic cycle for the synthesis of nucleotides, conversion of homocysteine to methionine, …

Seasonal Variation In Mitochondrial Bioenergetics Of The Bluegill Sunfish, Lepomis Macrochirus, From A Shallow Midwest River, Derick Isaac Lamptey

Masters Theses

As average global temperature increase, the frequency and magnitude of extreme temperatures in shallow aquatic ecosystems are more ubiquitous. In order to understand how these changing thermal regimes affect aquatic ectotherms, it is essential to develop studies evaluating the response of ectotherms to seasonal fluctuating thermal regimes. Previous studies on fluctuating temperature regimes have reported an increased physiological stress leading to morphological, behavioral and biochemical adaptations. From the latter, the adaptive capacity and seasonal performance associated with optimal function of the oxidative phosphorylation system (OXPHOS) are key for species persistence. However, studies on this matter are scarce. This study explores …

Therapeutic Dna: Delivery And As A Delivery Vehicle, Natalie J. Holl

Masters Theses

"A review of gene delivery methods and gene editing methods, as well as original research utilizing DNA as a delivery vehicle is presented in the following thesis. Thousands of diseases have been linked to genes. Gene therapy, either delivering therapeutic genes or editing DNA bases, has arisen as a treatment option with the potential to cure diseases, rather than just ease symptoms. Genes and editing tools need to be delivered to cells for these therapies to be effective and many techniques have been developed to address the issue of delivery. Nonviral and viral methods have been used to deliver nucleic …

Studies On The Interaction And Organization Of Bacterial Proteins On Membranes, Mariana Brena

Masters Theses

Bacteria have developed various means of secreting proteins that can enter the host cell membrane. In this work I focus on two systems: cholesterol-dependent cytolysins and Type III Secretion.

Cholesterol is a molecule that is critical for physiological processes and cell membrane function. Not only can improper regulation lead to disease, but also the role cholesterol plays in cell function indicates it is an important molecule to understand. In response to this need, probes have been developed that detect cholesterol molecules in membranes. However, it has been recently shown that there is a need for probes that only respond to …

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 …

Feronia-Related Receptor Kinase 7 And Feronia And Their Role In Receiving And Transducing Signals, David Vyshedsky

Masters Theses

Receptor kinases (RKs) are transmembrane proteins that have been shown to regulate an array of important processes in A. thaliana, including polar cell growth, plant reproduction, and many other plant growth processes. In this thesis, I examine RECEPTOR KINASE 7 (RK7) and FERONIA (FER), two closely related transmembrane RKs, and their effects on plant reproduction. The RK7 gene when knocked out (rk7) in conjunction with FER resulted in delayed plant growth, decreased seed yield, and a lower percentage of the seeds germinating as compared to the single FER knockout. Transgenic plants with GUS reporter driven by RK7 promoter …

In Vitro S-Glutathionylation Of S-Nitrosoglutathione Reductase From Arabidopsis Thaliana And Phenotype Determination Of Sensitive To Formaldehyde 1 Knockout Strains Of Saccharomyces Cerevisiae, Ian Truebridge

Masters Theses

Cells are constantly exposed to different stresses – one being redox stress, which is induced by metal, reactive oxygen species and reactive nitrogen species. S-nitrosoglutathione reductase (GSNOR) helps modulate redox stress by two different mechanisms – either by reducing S-nitrosoglutathione (GSNO) to oxidized glutathione (GSSG) or by oxidizing hydroxymethyl glutathione (HMGSH), a biproduct of glutathione and formaldehyde, to formic acid. GSNO has the potential to posttranslational modify proteins in two different manners, either by S-nitrosation or by S-glutathionylation. Interestingly, GSNOR can be modified by its substrate GSNO, either by S-nitrosation, which has previously been reported, or, as discussed in this …

Comparative Toxicology Of Nio And Ni(Oh)₂ Nanoparticles, Melissa Hope Cambre

Masters Theses

“Understanding the potential toxicity of nanoparticles (NPs) is important to ensure that these new products do not impose harmful effects to human and environmental health. Paper I is a literature review in which we discuss characteristics of nanomaterials, with an emphasis on transition metal oxide nanoparticles that influence cytotoxicity. Identification of those properties may lead to the design of more efficient and safer nanosized products for various industrial purposes and provide guidance for assessment of human and environmental health risk. We then investigate biochemical and molecular mechanisms of cytotoxicity that include oxidative stress-induced cellular events and alteration of the pathways …

Comparative Chemical Characterization Of Lunasin-Enriched Preparations And Modifications Of The Inflammasomes In Vitro, Samuel James Price

Masters Theses

Soybean (Glycine max) is one of the most cultivated crops in the world providing the population with large amounts of protein and oil. In addition to its nutritional composition, soybean also contains biologically active compounds with potential health-promoting properties. The presence of these bioactives may be responsible for the lower incidence of chronic diseases in populations that consume a significant portion of soybeans in their diet. One group of soybeanderived bioactives are bioactive peptides and proteins including lunasin, Bowman-Birk inhibitor (BBI) and Kunitz-type trypsin inhibitor (KTI). The overall objective of this research was to develop a method of …

Effects Of Asiatic Acid On Neurite Outgrowth In Neuro-2a Cells, Aishah Asiri

Masters Theses

Recently, medicinal plants from ancient Ayurvedic medicine have provided clues to the discovery of novel therapeutics for various diseases. In Ayurvedic medicine, a common Indian plant, Centella asiatica is highly regarded as a "rasayana" or nerve tonic. The Centella extract is used to ward off age-related dementia and to increase memory and intelligence. The mechanism by which Centella improves memory and learning and reduces the risk of dementia is unclear.

We recently tested the effects of asiatic acid, the main active component of Centella, on neuronal growth. We hypothesized that asiatic acid will promote neuronal growth and neurite network …

Lignin Maximization: Analyzing The Impact Of Different Feedstocks And Feedstock Ratios Using Organosolv Fractionation, Marc Banholzer

Masters Theses

Over-exploitation of fossil fuels coupled with increasing pressure to reduce carbon emissions are prompting a transition from conventional petrochemical feedstocks to sustainable and renewable sourced carbon. The use of lignocellulosic biomass as a feedstock for integrated biorefining is of current high interest, as separation into its component parts affords process streams of cellulose, hemicellulose and lignin, each of which can serve as a starting point for the production of biobased chemicals and fuels. Given the large number of potential sources of lignocellulosic feedstocks, the biorefinery will need to adapt to the supplies available over a normal growing season. Of particular …