Life Sciences Commons^™

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 …

The Gene Expression Patterns Of Phanerochaete Chrysosporium And Trametes Versicolor On Diverse Lignocellulosic Feedstocks, Noor Osama Alabbasi

Masters Theses

Plant biomass is considered to be an important future starting material for fuels and chemicals, thereby decreasing our reliance on fossil fuels. While direct combustion continues to be a source of fuel, the generation of liquid fuels from plant biomass for transportation has proven to be challenging. Among the limiting factors for conversion of this material to biofuels is the recalcitrant nature of lignocellulose, the primary component of non-starch plant biomass. A strategy to overcome this dilemma is to directly or indirectly use the enzymes from white-rot fungi, which have evolved a unique ability to deconstruct lignocellulose. However, the biochemical …

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 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 …

Reprograming Neuronal Cells By Overexpression Of Fibroblast-Specific Transcription Factors, Abdulmohsen Alanazi

Masters Theses

In mammals, a complex system of regulatory signals distinguishes tissues, structures and functions. Combinations of transcription factors and co-factors regulate activation and repression of genes that result in cellular differentiation. Whole genome arrays allow the monitoring of genomic expression in specific tissues. Fibroblast microarray studies have shown candidate genes that may be involved in fibroblast identification, including genes that express transcription factors Prrx1, Snai2 and Twist1. A previous study showed that the Prrx1 and Snai2 could reactivate a fibroblast phenotype in hybrid cells that had lost fibroblast identity. Furthermore, overexpression of these factors in liver-derived cells strongly repressed liver gene …

Functional Characterization Of Glutamate Carboxypeptidase Ii In Caenorhabditis Elegans, Hashni Epa Vidana Gamage

Masters Theses

Glutamate carboxypeptidase II (GCPII) is a transmembrane zinc metalloprotease expressed in a number of organisms: from yeast to worm to humans. In humans, GCPII has been observed as a multifunctional protein and expressed in prostate, intestine, kidney, brain, tumor-associated neovasculature and other tissues as five paralogs. In the human small intestine, hGCPII is proposed to facilitate the folate absorption by cleaving terminal glutamate residues in dietary folates. Folates act as a cofactor in one-carbon metabolic pathways such as nucleotide synthesis, amino acid synthesis, DNA repair, and consequently involved in cell division and growth. The hGCPII homolog is found in the …

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 …

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 …

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 …

Expression, Purification, And Characterization Of An Intrinsically Disordered Late Embryogenesis Abundant (Lea) Protein From Artemia Franciscana Utilizing Escherichia Coli And Nicotiana Tabacum, Md Fazlul Karim

Masters Theses

Anhydrobiosis is an astounding strategy that allows certain species (both animals and plants) to survive severe environmental conditions such as desiccation, extreme cold, or heat in the habitat. Despite the occurrence of several different molecular strategies, expression of highly hydrophilic polypeptides termed LEA proteins has been most conclusive identified as a requirement for the survival of plants and animals during periods of water stress such as freezing and drying. Several classification schemes for LEA proteins have been proposed and the brine shrimp, Artemia franciscana, is the only known animal that naturally expresses LEA proteins from three different classification groups …

White-Rot Fungi As Pretreatment Agents For Wood Destined For Biofuel Applications, Ryan M. Kalinoski

Masters Theses

Efficient and economical conversion of lignocellulosic biomass to biofuels is often hampered by the chemical recalcitrance of the material. Inexpensive and environmentally-friendly pretreatment processes are therefore desirable in order to lower the cost of biofuel production and minimize negative environmental impacts. To that end, we have explored the use of a naturally occurring white-rot fungus, Trametes versicolor, as a direct pretreatment agent for hardwood destined for biofuel applications. Specifically, we examined the pretreatment effects on the hardwood mixture after treatment with the wild-type strain of T. versicolor (52J) compared with those from a cellobiose dehydrogenase (CDH)-deficient strain (m4D) , …

Functions Of Mitoneet: What The Protein-Protein Interactions Reveal, Fran Hirschfelder

Masters Theses

MitoNEET is a [2Fe-2S] cluster protein found on the outer mitochondrial membrane. First discovered as a binding site for pioglitazone, an anti-diabetic drug, it was the first protein described containing a CDGSH iron-sulfur domain (CISD). However, the function(s) of mitoNEET in both normal cellular physiology and the physiology in type-2 diabetes remains unclear. The proposed functions of mitoNEET, include cluster transfer, electron transport and oxidative respiration. This thesis describes the use of proteomic pull-down techniques to identify possible protein binding partners of mitoNEET from both mouse and human liver cell lysates. In order to accomplish this, the expression and purification …

Determination Of Structural Stabilities Of Metal-Free Porphyrin Cytochrome C, Zinc Cytochrome C, And Cobalt Cytochrome C, Usha K. Tottempudi

Masters Theses

No abstract provided.

Molecular Mechanisms Involved In Anhydrobiosis Of Insect Cells, Diyagama Arachchi Ralalage Dilini Sewwandi Samarajeewa

Masters Theses

Animals possessing tolerance to extreme water stress are termed anhydrobiotes. Many desiccation tolerant organisms respond to water stress by intracellular accumulation of selected sugars such as trehalose and larger macromolecules such as Late Embryogenesis Abundant (LEA) proteins and thereby maintain the cell viability. Evidence indicates that the presence of trehalose and Late Embryogenesis Abundant (LEA) proteins may work synergistically to confer cellular protection during drying in eukaryotic cells. We evaluated any increase in cellular desiccation tolerance by expressing different LEA proteins in a non-desiccation tolerant insect cell line Drosophila melanogaster (fruit fly) (Kc167 cells) in the presence of trehalose.

Transgenic …

Investigating The Allosteric Behavior Of Malate Dehydrogenase From Escherichia Coli, Eman M. Ghanem

Masters Theses

Regulatory mechanisms of malate dehydrogenase from E.coli (eMDH) involving NADH as an allosteric effector were investigated. The reaction was studied in both directions: malate oxidation and oxaloacetate reduction. When malate was the variable substrate, a plot of rate against substrate concentration was sigmoidal in the presence of 0.065 mM NADH, which indicates the presence of an allosteric site for NADH on the enzyme. Binding of NADH at the allosteric site causes conformational changes in the active site and, thereby, changes the catalytic activity of the enzyme. An increase in K_m value, from 1.3 to 3.9 mM malate was observed, …

Mechanistic Studies On Malate Dehydrogenase From Escherichia Coli, S. Kirk Wright

Masters Theses

Kinetic studies and chemical modification studies were performed on malate dehydrogenase from Escherichia coli (eMDH). Chemical modification studies using diethylpyrocarbonate and iodoacetic acid, along with log V/K profiles indicate that one ionizing group with a pK_a between 7.9 and 8.5 acts as a general acid/base in the catalytic mechanism. Log V profiles suggest that malate binds to the correctly protonated form of the enzyme. These results imply that a histidine residue is required for catalysis.

A primary deuterium kinetic isotope effect of 1.43 (±0.14) was observed on V/K using malate-2-d, while no isotope effect was measured on V_{max …}

The Effects Of Various Adenosine And Xanthine Analogues On Mammalian Sperm Motility, Daniel Joseph Cushing

Masters Theses

Caffeine, theophylline, and a number of other xanthine analogues have been shown to stimulate the motility of mammalian spermatozoa. The mechanism by which these compounds act was assumed to be cAMP phosphodiesterase inhibition. However, it has recently been shown that many of the responses elicited by alkylxanthines and their analogues in various tissues are not the result of cAMP phosphodiesterase inhibition but by antagonism of endogenous adenosine. Using the recently described transmembrane migration method this study observed the effect of a number of xanthine and adenosine analogues on mammalian sperm motility. The hypothesis to be tested was that the increase …

Response Of A Nitrifying Biofilm To Copper, Denise Moldroski Mott

Masters Theses

In pure cultures of Nitrosomonas, copper is known to cause a stimulation of nitrification at low levels (≤ 0.03 mg Cu⁺²/1) and an inhibition affect at higher levels (≥ 0.05 mg Cu⁺²/1). Nitrifying activated sludges are much more tolerant of copper showing only 75% inhibition at 150mg Cu⁺²/1. The purpose of this paper was to determine the copper sensitivity of a nitrifying biofilm grown in a continuous flow trickling filter system.

A continuous flow trickling filter system was built using limestone chips for the biofilm substrate. The biofilm was established from secondary effluent. …

A Comparison Of The Acidic Extracellular Polysaccharides From Rhizobium Trifolii Mutants Affected In Trifolium Repens Root Hair Curling, Brian Andrew Hanley

Masters Theses

The compositions and sugar linkages of the acidic extracellular polysaccharide (EPS) from several Rhizobium trifolii mutants were compared. These mutants were derived from a wild type Rhizobium trifolii, ANU843, and are unable to cause normal root hair curling, Hac-, or nodulate clover, Nod-. Three of the mutants contain a Tn5 insertion in a 5.3 kb BglII fragment of the symbiotic plasmid (pSym). A fourth mutant is missing the pSym, which includes much of the 5.3 kb BglII fragment, both of these deletions result in Hac-Nod- phenotypes. When the 5.3 kb BglII fragment is cloned (pRT150) and reinserted into the …

Comparison Of Surface Polysaccharides Of R. Leguminosarum Anu57 (Exo-1), R. Leg. Anu57(Pbr1an) (Nod+, Nif-), And R. Leg. Anu57(Pjb5j1) (Nod+, Nif-), Frank G. Hustmyer

Masters Theses

Extracellular polysaccharides (EPS) and lipopolysaccharides (LPS) are suspected to be involved in the legume/Rhizobium symbiotic process. Polysaccharide compositions from the EPS, LPS, capsular polysaccharide (CPS), and small polysaccharide (SmPS) were compared between Rhizobium leguminosarum ANU57 (parent, Exo^-1) and two mutants R. leg. ANU57(pBR1AN) (nod⁺, nif^-) and R. leg. ANU57(pJB5J1) (nod⁺, nif^-) both containing a Sym (symbiotic) plasmid insertion. R. leg. ANU57(pBR1AN) and R. leg. ANU57(pJB5J1) are nod⁺ on clover and peas, respectively. The nod⁺ mutants produce larger amounts of EPS and decreased amounts of LPS compared to …

Analysis Of The Surface Polysaccharides Of R. Trifolii Su843 And Its Sym Plasmid Alterated Mutants, Jauh-Lin Duh

Masters Theses

The Rhizobium trifolii polysaccharides from SU843 and mutants--HC843(pBR1AN), HC843, 8002--in which the sym plasmid is replaced, absent, or mutated by transposon Tn5 were isolated. The surface polysaccharides of genetically altered mutants were compared quantitatively and qualitatively with one another and with the parent strain. The interpretation of these results is discussed in relation to the function of Rhizobium surface polysaccharides in the symbiotic process. The symbiotic ability of SU843 and mutant strains is as follows: (a) SU843, nod⁺, fix⁺; (b) mutant 8002, roa⁺ (still attaches to root hair), hac^-, nod^-; (c) …

The Relationship Between Whole Brain Catecholamine Depletion In Carassius Auratus And The Exposure To Inescapable Shock In A Learned Helplessness Paradigm, Roderick J. Misunis

Masters Theses

Learned helplessness is a psychological concept that describes the subsequent escape-avoidance behavior of experimental subjects who are exposed to uncontrollable stressors. Subjects after treatment are unable to respond in situations where escape is possible. Two major theorists, Seligman and Weiss, have proposed explanations concerning the phenomena. Seligman feels that the subject is unable to respond due to the fact that the exposure to an uncontrollable stressor has caused him to learn to be "helpless". Weiss feels that the inability to respond can best be described by alterations in the subject's brain neurochemistry, specifically the neurotransmitter norepinephrine. This paper is an …

Investigations Of Possible Allelopathic Effects Of Lycopodium Flabelliforme (Fern.) Blanch., Joan Macuszek

Masters Theses

Lycopodium flabelliforme (Fern.) Blanch. sporophytes were collected from a colony west of Flat Rock in Crawford County, Illinois. The material was either ground to a coarse grade using a Wiley Mill (grindate), left whole and untreated (fresh) or water extracted with a Waring blender (extract). The effect of the sporophyte material was tested on the germination of seeds and on the growth of seedlings of Raphnus sativa L. Sporophytes subjected to the grindate treatment showed the most inhibitory effects. It was shown that the alledged inhibitory substance was heat stable and able to be concentrated. Using column chromatography, at 37.7°C, …

An Analysis Of Sugars In Vein Tissue And Free Mesophyll Cells Of Squash Leaves, Charles Wayne Kennedy

Masters Theses

No abstract provided.