Physical Sciences and Mathematics Commons^™

Development Of A Novel Electron-Transfer Secondary Reaction Matrix, Characterization Of The Site–Specificity Of Novel Bilin-Lyase, And Fundulus Grandis Protein Expression Investigation Using Mass Spectrometry, Mohamed N. Boutaghou

University of New Orleans Theses and Dissertations

Reported in this dissertation are the results of investigations performed at the New Orleans Center for Mass Spectrometry at the University of New Orleans. The projects that are detailed in the coming pages take on a variety of subjects, but a common thread is that each employs matrix-assisted laser desorption/ionization (MALDI) mass spectrometry to solve a problem. Fundamental aspects of MALDI in-plume ionization are implicated in the introduction of a newly developed electron-transfer secondary ionization matrix. The remaining projects are related to the ever expanding field of proteomics. Mass spectrometry was used to investigate the site specificity of a newly …

Structure And Dynamics Of The Membrane Protein Bacteriorhodopsin Studied By Mass Spectrometry, Yan Pan

Electronic Thesis and Dissertation Repository

Membrane proteins continue to represent a major challenge for most analytical techniques. Using bacteriorhodopsin (BR) as model system, this work aims to develop mass spectrometry (MS)-based approaches for exploring the structure, dynamics and folding of membrane proteins.

As the first step, BR in its native lipid environment was exposed to hydroxyl radicals, which were produced by laser photolysis of hydrogen peroxide. It was found that the resulting methionine (Met) labeling pattern was consistent with the known BR structure. This finding demonstrates that laser-induced oxidative Met labeling can provide structural information on membrane proteins. In subsequent experiments, the effects of different …

Molecular Dynamics Simulations Of Charged Nanodroplets, Elias Ahadi

Electronic Thesis and Dissertation Repository

Charged nanodroplets represent a fascinating research area due to their unique dynamics and physical properties. These nanodroplets play a key role in electrospray mass spectrometry (ESI-MS), which is a method for analyzing organic/inorganic molecules as well as proteins and other biomolecular species. The mechanism whereby these analytes are transferred into the gas phase as intact ions remains incompletely understood. Two competing models have been proposed to explain the process, the charged residue model (CRM) and the ion evaporation model (IEM). Under the CRM, evaporation of the droplet proceeds until dryness, at which point the analyte ion is left behind. Under …

Advanced Techniques In Mass Spectrometry For Qualitative And Quantitative Protein Characterization, Andrew Boissy Dykstra

Doctoral Dissertations

Though mass spectrometry has earned a central role in the field of proteomics due to its versatility in a wide range of experiments, challenges and complications are still encountered when using mass spectrometry to characterize protein structures, post-translational modifications (PTMs), and abundances. In this dissertation, analytical methods utilizing mass spectrometry have been developed to address challenges associated with both qualitative and quantitative protein characterization. The effectiveness of using multiple pepsin-like proteases, both separately and in mixtures, combined with online proteolysis using a special triaxial probe has been demonstrated on an amyloid beta peptide related to the onset of Alzheimer’s disease. …

Novel Ion Trap Made Using Lithographically Patterned Plates, Ying Peng

Theses and Dissertations

A new approach of making ion trap mass analyzers was developed in which trapping fields are created in the space between two ceramic plates. Based on microfabrication technology, a series of independently-adjustable electrode rings is lithographically patterned on the facing surfaces of each ceramic plate. The trapping field can be modified or fine-tuned simply by changing the RF amplitude applied to each electrode ring. By adjusting the potential function applied to the plates, arbitrary trapping fields can be created using the same set of ceramic plates. Unlike conventional ion traps, the electrodes of planar ion traps have a non-equipotential surface, …

Development Of Bioanalytical Methods For Clinical Applications And Drug Screening, Xiaohan Cai

ETD Archive

In the past decade, bioanalytical method development has become an integral part of clinical diagnosis, biomarker discovery, and drug discovery and development. The new and emerged bioanalytical technologies allow the quantitative and qualitative analysis of small molecules and biomolecules with high sensitivity and specificity. Specifically, the bioanalytical methods based on LC-MS and methylation-specific PCR are well suited for detecting low-abundance metabolites, proteins, and DNA in biofluids and tissues for biomarker investigation. They offer great clinical promises for early diseases diagnosis and therapeutic interventions. Besides, the LC-MS/MS quantitative method is essential for the estimation of pharmacokinetic and toxicological properties in drug …

Development Of Quantitative Lc-Ms/Ms Methods For The Pharmacological Studies Of Anti-Cancer Drugs, Lan Li

ETD Archive

In the development of anti-cancer drugs, it is essential to study the pharmacological profiles of the drugs. Among the analytical tools utilized in the pharmacological studies, LC-MS/MS has gained increased popularity due to its unequivocal sensitivity and specificity, as well as the ability of handling a wide variety of compounds with relatively simple sample preparation procedures. In this work, a brief review on the method rational, instrumentations, analytical method validation, and work flow of the method development was included. The processes of LC-MS/MS method development for the pharmacological studies of three anti-cancer drugs (i.e., methoxyamine, fludarabine, and 6-benzylthioinosine) were illustrated. …

Capillary Gradient Chromatofocusing-Mass Spectrometry;A Sensitive Approach For Protein Analysis, James Anthony Hribar

ETD Archive

Gradient chromatofocusing-mass spectrometry is a new technique for protein analysis recently introduced by our research group. Capable of separating and identifying proteins according to pI values and molecular weight, gradient chromatofocusing-mass spectrometry has been achieved by integrating a new ion-exchange chromatography technique called gradient chromatofocusing with a newly discovered buffer system that promotes mass spectrometry detection. Differing from traditional ion-exchange chromatography techniques, gradient chromatofocusing employs specific low molecular weight, volatile buffer components that are introduced onto an ion-exchange HPLC column by programming a binary gradient pumping system to deliver the correct proportions of acidic mobile phase to overcome buffering of …

Quantitative And Qualitative Mass Spectrometric Analysis Of Anticancer Agents, Drugs Of Abuse And Enzyme-Inhibitor Complexes, Keri M. Smith

ETD Archive

Mass spectrometry is a valuable tool in the analysis of many types of compounds. From small molecules to large proteins, mass spectrometry can help to interrogate samples and give insights to the origins of disease as well as calculate an exact concentration. Bioanalytical method development is an integral component in the measurement of such compounds. To facilitate proper analytical investigation, the process of method development, analysis, and interpretation must be understood. This work describes the basis and procedure for bioanalytical method development and its detailed application to preclinical studies of the antineoplastic agent hexamethylene bisacetamide and measurement ofillicit drugs of …

Proteomic Analysis Of The Blood Of Alligator Mississippiensis, Lancia Nadinia Fallen Darville-Bowleg

LSU Doctoral Dissertations

My research focus was to investigate alligator blood using mass spectrometry-based proteomics methods to understand their innate immune systems. The first goal was to sequence peptides and proteins from the blood serum and leukocytes using tandem mass spectrometry and de novo sequencing. The second goal was to determine the function of these biological molecules and their relationship to the immune system. One- and two-dimensional gel electrophoresis was used to separate proteins from alligator leukocytes, which were enzymatically digested. The peptides were measured using reversed phase nano-high performance liquid chromatography coupled with tandem mass spectrometry (nano-HPLC-MS/MS) followed with de novo sequencing. …