Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 9 of 9
Full-Text Articles in Physical Sciences and Mathematics
Investigations Of The Structure And Protein-Protein Interactions Of Chlamydia Trachomatis Scc4, Thilini Oshadhi Senarath Ukwaththage
Investigations Of The Structure And Protein-Protein Interactions Of Chlamydia Trachomatis Scc4, Thilini Oshadhi Senarath Ukwaththage
LSU Doctoral Dissertations
Chlamydia trachomatis (CT) is the most common, sexually transmitted bacterial disease (STD) in the world. In the developmental cycle of CT, specific chlamydia chaperone 4 (Scc4) is a unique protein with essential and multiple roles. Hence, Scc4 is significant as a virulence target for therapeutic approaches to treat chlamydial infections. A novel approach was discovered to purify tag free Scc4 by utilizing a 6X-histidine-tag on Scc1 in the co-expressed Scc4:Scc1 complex by capturing the complex on nickel-charged immobilized metal affinity chromatography resin, followed by dissociation of Scc4 with sarkosyl. Using triple resonance NMR experiments, backbone and sidechain resonances …
Hydroformylation And Aldehyde-Water Shift Catalysis By Dirhodium Tetraphosphine Complexes, Marshall Douglas Moulis
Hydroformylation And Aldehyde-Water Shift Catalysis By Dirhodium Tetraphosphine Complexes, Marshall Douglas Moulis
LSU Doctoral Dissertations
The use of a unique tetraphosphine ligand (et,ph-P4) allows for the chelating of two rhodium centers to perform bimetallic coopertivity in hydroformylation reactions to better the yields the linear aldehyde product. The proposed catalyst is [Rh2(μ-H)2(CO)4(rac-et,ph-P4)]2+ and has been studied by in situ FT-IR and NMR. When tested in a polar phasic acetone/water (30 % by vol.), the catalyst forms a monocationic system [Rh2(μ-H)2(CO)4(rac-et,ph-P4)]+ that has an initial TOF of 26 min-1, selectivity of 27:1 L:B, and low byproducts of …
Fundamental Studies Of Humic Acid's Influence On Pollutant Toxicity To Aquatic Organisms, Rachel Dawn Deese
Fundamental Studies Of Humic Acid's Influence On Pollutant Toxicity To Aquatic Organisms, Rachel Dawn Deese
LSU Doctoral Dissertations
The main purpose of the research presented in this dissertation was to further understand the intricate and convoluted interactions between natural organic material, biological entities, and pollutants. This was achieved by utilizing humic acids (HAs) from differing sources, chemically modified humic acid, two biological entities (model biomembranes and Artemia Franciscana), and three types of pollutants (cations, surfactants, and carbon nanotubes). Fluorescence spectroscopy and model biomembranes were used to measure the change in HA’s ability to interact with the biomembranes in the presence of cations. Three differently sourced HAs, chemical modified HAs, and a range of cations were studied to elucidate …
Investigating The Structure Of The Papain-Inhibitor Complex Using Spr And Nmr, Margaret Sara Thomasson
Investigating The Structure Of The Papain-Inhibitor Complex Using Spr And Nmr, Margaret Sara Thomasson
LSU Doctoral Dissertations
Cysteine proteases (CPs) are enzymes with a nucleophilic thiol in their active sites. Inhibitors of cysteine proteases (ICPs) occur naturally in bacterial pathogens and some protozoa. In parasites, ICPs are often virulence factors, contributing to the formation and survival of amastigotes within host cells. These amastigotes have higher CP activity, therefore making both ICPs and CPs potential drug targets. Despite great genetic variability, ICPs contain highly conserved structural features, including a series of defined loops that play a significant role in binding CPs. Papain, a CP from Carica papaya, complexes with ICP from Leishmania mexicana. Although the individual 3-D structures …
Platinum Complexes With Tridentate Ligands As Models For Active Monofunctional Anticancer Drugs, Chase Koby Andrepont
Platinum Complexes With Tridentate Ligands As Models For Active Monofunctional Anticancer Drugs, Chase Koby Andrepont
LSU Doctoral Dissertations
Pt(II) complexes bind preferentially at N7 of G residues of DNA, causing DNA structural distortions associated with anticancer activity. Some distortions induced by difunctional cisplatin are also found for monofunctional Pt(II) complexes with carrier ligands having bulk projecting toward the guanine base. This ligand bulk can be correlated with impeded rotation about the Pt–N7(guanine) bond. The objective of this study is to understand the influences of in-plane bulk of Pt(Ltri)G adducts (Ltri = tridentate carrier ligand, G = guanine derivative bound to a metal, but not tethered to another nucleobase). NMR spectroscopy provided conclusive evidence that Pt(Ltri)G (Ltri = di-(2-picolyl)amine …
Oligomers Of Beta-L-Arabinosides Of Hydroxyproline : Synthesis Of The Carbohydrate Epitope Of The Art V 1 Allergen, Ning Xie
LSU Doctoral Dissertations
The pollen of mugwort is a major contributor to hay fever in Europe and North America. The chemical structure of Art v 1, the major allergen of mugwort, has been elucidated. A notable motif in Art v 1 – characterized by clusters of contiguous â-arabinosides of hydroxyproline – was found to be a key recognition element for antibodies generated in response to the natural protein. This dissertation details the chemical synthesis of oligomers of â-arabinosides of hydroxyproline and the search to establish the minimal carbohydrate epitope of Art v 1. The â-arabinoside motif, being a 1,2-cis glycoside, presents a considerable …
Investigations Into Alkene Hydration And Alkene Oxidation Catalysis, William Schreiter
Investigations Into Alkene Hydration And Alkene Oxidation Catalysis, William Schreiter
LSU Doctoral Dissertations
Bimetallic Ni complexes Ni21M and Ni21R and monometallic transition metal complexes were investigated as possible alkene hydration catalysts under a multitude of different reaction conditions. All attempts at performing this catalytic reaction failed to give any alcohol products. Catalytic screening experiments were conducted using a mixture of racemic-et,ph-P4 and meso-et,ph-P4, 1M and 1R, and various transition metals. These experiments gave several different products including 1-phenylethanol from styrene. During the course of the hydration experiments, an aldehyde product was identified from experiments conducted with the bimetallic complexes in air. Experiments have shown that the aldehyde is produced from the oxidative cleavage …
Probing The Association Behavior Of Hydrophobic Organic Compounds With Dissolved Humic Materials, Hadi M. Marwani
Probing The Association Behavior Of Hydrophobic Organic Compounds With Dissolved Humic Materials, Hadi M. Marwani
LSU Doctoral Dissertations
The association mechanism between hydrophobic organic compounds (HOC) and dissolved humic materials (DHM) has continued to be one of the interesting areas in environmental applications. The goal of the research reported in this dissertation is to investigate the association behavior of HOC with DHM. The first part of this research involves steady-state fluorescence measurements of these multi-component systems to study the effect of DHM content on the association mechanism of HOC, in particular using pyrene as a model. Results showed that steady-state fluorescence alone may not provide enough information about the quenching mechanism of pyrene with DHM. Lifetime based fluorescence …
Ab Initio Molecular Dynamics Simulations Of Methylaluminoxane (Mao) Synthesis By Hydrolysis Of Trimethylaluminum, Lacramioara Negureanu
Ab Initio Molecular Dynamics Simulations Of Methylaluminoxane (Mao) Synthesis By Hydrolysis Of Trimethylaluminum, Lacramioara Negureanu
LSU Doctoral Dissertations
MAO is the co-catalyst in the metallocene catalytic systems, which are widely used in single site olefin polymerization due to their high stereoselectivity. To date, the precise structure of MAO, the particular compound or compounds catalytically active in MAO, have eluded researchers. MAO, a white amorphous powder, is not a good sample for a direct spectroscopic characterization, and its NMR spectra are broad and almost featureless. Many structural models have been proposed but none are generally accepted. In the first part of this work the MAO formation mechanism was addressed. Molecular dynamics simulations at MP2 configuration interaction theory level have …