Biochemistry Commons^™

The Distinctive Regulatory Mechanisms Of Bacterial Acetyl-Coa Carboxylase, Alexandra Leigh Evans

LSU Doctoral Dissertations

Metabolic Regulation is a complex system used to control cellular metabolism in response to conditions in the cell’s environment. For most enzymes, the cell can rely upon a minimal amount of regulation; however, critical enzymes, such as acetyl-CoA carboxylase, must be regulated at multiple levels. Acetyl-CoA carboxylase catalyzes the first committed step in fatty acid synthesis. In bacteria, acetyl-CoA carboxylase forms a complex of three subunits–biotin carboxylase, biotin carboxyl carrier protein, and carboxyltransferase–which catalyze the carboxylation of acetyl-CoA to form malonyl-CoA via two half-reactions. In the first half-reaction, biotin covalently linked to biotin carboxyl carrier protein is carboxylated by biotin …

Direct Quantification Of Deubiquitinating Enzyme Activity In Single Intact Cells, Nora Safabakhsh

LSU Doctoral Dissertations

Challenges in drug efficacy occur during the treatment of most types of cancer due to the heterogeneity of the tumor microenvironment. This has led to the development of personalized medicine. Due to the clinical success of the proteasome inhibitors Bortezomib and Carfilzomib in treatment of multiple myeloma, interest has shifted towards molecularly-targeted chemotherapeutics for ubiquitin-proteasome system (UPS). Deubiquitinating enzymes (DUBs) are an essential part of this pathway which have been found to promote Bortezomib resistance in multiple myeloma patients. Unfortunately, there is a lack of specific, high throughput biochemical assays to characterize DUB activity in patient samples before and after …

Data-Driven Computational Approach To Study Bio-Molecular Interactions, Misagh Naderi

LSU Doctoral Dissertations

Proteins commonly convey their functions in coordination with other proteins, small molecules and/or other biological assemblies such as sugars, lipids, DNA or RNA. Understanding the nature of these interactions is therefore central to improving our knowledge of biological systems. This body of work is a consolidation of three different computational approaches to study bio-molecular interactions: large-scale protein-ligand modeling, fragment-based cheminformatics, and computational analysis of interactions in single proteins.

The first issue that is addressed in this study is the scarcity of atomic crystal structures of protein-drug complexes. In general, a drug molecule’s affinity for multiple protein targets may causes unsolicited …

Cloning, Purification, And Preliminary Dna-Binding And Unfolding Results For The Dna Polymerase I From The Psychrophile Psychromonas Ingrahamii, John Tod Baker

LSU Master's Theses

Psychromonas ingrahamii is a psychrophilic bacterium that lives in Arctic polar sea ice and grows at a temperature range of -12 to 10º C. This bacterium resides within veins inside the ice where the salinity is high, resulting in a freezing point depression and liquid water. The large fragment of DNA polymerase I from Psychromonas ingrahamii, called Klenpin, has been cloned, expressed, and purified in our laboratory. Although enzyme kinetic studies have been performed on a few psychrophilic enzymes, the thermodynamics of ligand binding and of protein stability have not been well studied for this class of extremophilic proteins. …

Evaluation Of Controlled-Release Nitrogen And Potassium Fertilizer In Louisiana Sugarcane Production, Samuel Kwakye

LSU Master's Theses

Sugarcane (Saccharum spp) production is an integral part of Louisiana's economy. Proper fertilizer management, particularly nitrogen (N) and potassium (K), optimizes sugarcane production. An experiment was established in 2015 at the LSU AgCenter Sugar Research Station in St. Gabriel, Louisiana to: (1) assess the effect of N and K fertilizer sources on sugarcane yield and quality parameters, and (2) monitor the changes in inorganic N and K levels in the soil at different sugarcane growth stages. The experiment was arranged in a randomized complete block design on a Sharkey clay soil and complete randomized design on a Commerce …

Breaking Conventions: Ohrr, A Transcriptional Regulator From Burkholderia Thailandensis, Anuja Rajiv Pande

LSU Doctoral Dissertations

Organic peroxides (OPs) are highly toxic oxidants. They directly react with cellular macromolecules rendering them inactive. Soil bacteria live in an oxidative environment rich in OPs from plant exudates and other xenobiotic compounds. Bacteria also face a burst of organic peroxides (lipid peroxides) in the macrophages during host invasion. Prokaryotes sense oxidative changes in environment and modulate their gene expression as an adaptive response for survival. MarR (multiple antibiotic resistance regulators) proteins enable bacteria to respond to such stress. Resistance to organic oxidants has been hypothesized to help bacteria survive in presence of disinfectants. This increases nosocomial infection rate.

Bacteria …

Changes In Carbon, Nutrient, And Trace Metal Concentrations During The Transition From Freshwater To Marine Environments - A Case Study In Southwest Louisiana, Songjie He

LSU Doctoral Dissertations

Rivers carry terrestrial nutrients and other materials to estuaries, affecting biogeochemical cycles and ecosystems in coastal margins. This dissertation research incorporated five studies to investigate the dynamics of carbon, nutrients, and trace metals in four major coastal rivers in southwest Louisiana – the Sabine, Calcasieu, Mermentau, and Vermilion Rivers. The overarching goal of this research was to broaden the knowledge and understanding of biogeochemical processes in freshwater – saltwater mixing zones. These studies employed decade-long monitoring records of water chemistry, utilized monthly field measurements conducted over a two-year period, and used analysis of over 200 water samples for carbon, nitrogen, …