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Mass spectrometry

Analytical Chemistry

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Full-Text Articles in Physical Sciences and Mathematics

Development Of Novel Protein Digestion And Quantitation Methods For Mass Spectrometic Analysis, Yongling Ai Dec 2023

Development Of Novel Protein Digestion And Quantitation Methods For Mass Spectrometic Analysis, Yongling Ai

Dissertations

Proteins are the workhorses of biology, playing multifaceted roles in maintaining cellular function, signaling, and response to environmental cues. Understanding their abundance and dynamics is pivotal for unraveling the complexities of biological processes, which underpins the foundations of molecular and cellular biology. Accurate measurement of protein quantities provides insights into cellular homeostasis, facilitates the discovery of biomarkers, and sheds light on the molecular mechanisms of diseases, bridging the gap between the molecular intricacies of proteins and their functional consequences in health and disease. The evolution of protein quantitation methodologies, from classical colorimetric assays to sophisticated mass spectrometry-based approaches, has expanded …


Enhanced Methods In Forensic Mass Spectrometry For Targeted And Untargeted Drug Analysis, Dina M. Swanson Jun 2023

Enhanced Methods In Forensic Mass Spectrometry For Targeted And Untargeted Drug Analysis, Dina M. Swanson

USF Tampa Graduate Theses and Dissertations

Forensic science has long used mass spectrometry for the analysis of drugsand metabolites. Traditionally, screening methods consisted of color tests or immunoassay and confirmation methods used gas chromatography with mass spectrometry, which was considered the gold standard for identification. In the last several decades, advances in liquid chromatography with mass spectrometry (LCMS) have brought this technology to the forefront of forensic drug identification. Drug identification in forensic drug chemistry and forensic toxicology has become increasingly challenging due to the rapid increase in illicit drug analogs including novel opioids such as fentanyl analogs. Traditional screening methodologies are often unable to identify …


Utilizing Ultra-Performance Chromatography High-Resolution Mass Spectrometry To Investigate Fatty Acid Mediated Antibiotic Tolerance, Brittni Woodall May 2023

Utilizing Ultra-Performance Chromatography High-Resolution Mass Spectrometry To Investigate Fatty Acid Mediated Antibiotic Tolerance, Brittni Woodall

Doctoral Dissertations

The lipid membrane is the first component necessary to sustain life. To maintain homeostasis, segregate cellular machinery, provide protection from the environment, and reproduce, an organism must establish a boundary in which the processes can occur. Throughout the last two decades, research has propelled our knowledge of lipid membranes much beyond original hypotheses. Once thought of to be static and uniform, the understanding of the lipid membrane has evolved to encompass a structure that is responsive, unique, and intricately constructed by the organism itself. By chance or by choice, organisms adapt the lipid membrane according to the environment for which …


Quantitative Analysis Of The Proteomic Selectivity Of Acidic Reductive Alkylation Of Peptides, Connor Jewell May 2023

Quantitative Analysis Of The Proteomic Selectivity Of Acidic Reductive Alkylation Of Peptides, Connor Jewell

Honors Scholar Theses

Proteome quantification is a complicated process which takes on many methods, usually involving peptide derivatization and complex mass spectral analysis. Scores of techniques have been utilized to address issues of incomplete quantification. The implementation of IPTL labeling, or isobaric peptide terminal labeling, is a recent addition to the literature, which exploits the supposedly selective labeling of N-termini of tryptic peptides from the C-termini of lysine residues due to differences in basicity. This method has been shown to improve quantitation by reducing spectral complexity and provide more accurate and reproducible results on peptide abundance. Investigations into the selectivity of terminal derivatization …


Investigation Of Early Complex Formation Of Huntingtin Protein With And Without Lipids, Alyssa R. Stonebraker Jan 2023

Investigation Of Early Complex Formation Of Huntingtin Protein With And Without Lipids, Alyssa R. Stonebraker

Graduate Theses, Dissertations, and Problem Reports

Huntington’s disease (HD) is a fatal neurodegenerative disease caused by the expansion of the polyglutamine (polyQ) domain of the huntingtin protein (htt). The expansion of the polyQ domain beyond a threshold of approximately 35 repeats triggers complex toxic aggregation mechanisms and results in altered interactions between htt and lipid membranes. Many factors modulate these processes. One such modulator includes sequences flanking the polyQ domain, most notably the first 17 amino acids at the N-terminus of the protein (Nt17), and environmental factors including the presence of membranous structures. Nt17 has the propensity to form an amphipathic a-helix in the presence of …


The Influence Of Instrumental Sources Of Variance On Mass Spectral Comparison Algorithms, Isabel Cristina Galvez Valencia Jan 2023

The Influence Of Instrumental Sources Of Variance On Mass Spectral Comparison Algorithms, Isabel Cristina Galvez Valencia

Graduate Theses, Dissertations, and Problem Reports

Current search algorithms for the identification of substances based only on their electron ionization mass spectra provide the correct compound as their top result approximately 80% of the time. One contributing factor to the ~20% deviation in the first-hit recognition rate is that traditional algorithms work by comparing the unknown spectrum to an ‘ideal’ or consensus spectrum of each reference compound. The inclusion of replicate reference spectra in a database has been shown to improve the probability of ranking the correct identity in the number one position, but the variance in ion abundances caused by different conditions or different instruments …


Application Of Mass Spectrometry For The Characterization Of Synthetic Oligomers And Natural Lignin, Poorya Kamali Jan 2023

Application Of Mass Spectrometry For The Characterization Of Synthetic Oligomers And Natural Lignin, Poorya Kamali

Theses and Dissertations--Chemistry

As part of the ongoing effort to substitute finite fuel and chemical resources with renewable ones, biomass is emerging as one of the most promising sources. Biomass consists of three main components of cellulose, hemicellulose, and lignin. Traditionally, cellulose has been used extensively in pulping industry, while lignin has been considered waste and is burned to generate heat. Lignin, a complex aromatic polymer component of biomass, has the potential to be used as a source of aromatic chemicals and pharmaceutical synthons. The recalcitrant nature of lignin, the lack of effective lignin breakdown methods and analytical techniques to analyze it are …


Natural Product Discovery And Mycotoxin Analysis Of Agricultural Endophytes And Pathogens, Jacob P. Walsh Sep 2022

Natural Product Discovery And Mycotoxin Analysis Of Agricultural Endophytes And Pathogens, Jacob P. Walsh

Electronic Thesis and Dissertation Repository

This thesis focuses on the application of fungal natural product chemistry for the use of agriculture fungal pathogenesis research. The research in this work uses many analytical chemistry techniques and instruments such as HPLC, LC-MS/MS and NMR. In Chapter 2, a diagnostic fragmentation module was developed for the identification of compound classes in crude fungal extracts. This module identified the classes cytochalasins and chaetoglobosins from extracts of Penicillium, Chaetomium, and Xylaria. From these extracts a new chaetoglobosin was discovered and the module was implemented into the open-source software package MZmine 2.0. Chapter 3 discusses analytical chemistry techniques with the …


Meta-Analysis Reveals Both The Promises And The Challenges Of Clinical Metabolomics, Heidi E. Roth, Robert Powers Aug 2022

Meta-Analysis Reveals Both The Promises And The Challenges Of Clinical Metabolomics, Heidi E. Roth, Robert Powers

Chemistry Department: Faculty Publications

Clinical metabolomics is a rapidly expanding field focused on identifying molecular biomarkers to aid in the efficient diagnosis and treatment of human diseases. Variations in study design, metabolomics methodologies, and investigator protocols raise serious concerns about the accuracy and reproducibility of these potential biomarkers. The explosive growth of the field has led to the recent availability of numerous replicate clinical studies, which permits an evaluation of the consistency of biomarkers identified across multiple metabolomics projects. Pancreatic ductal adenocarcinoma (PDAC) is the third-leading cause of cancer-related death and has the lowest five-year survival rate primarily due to the lack of an …


Analysis Of The Zebrafish Olfactory System Using Immunohistochemistry And Enhanced Techniques Of Desorption Electrospray Ionization Mass Spectrometry (Desi-Ms), Tara Lynn Maser Jun 2022

Analysis Of The Zebrafish Olfactory System Using Immunohistochemistry And Enhanced Techniques Of Desorption Electrospray Ionization Mass Spectrometry (Desi-Ms), Tara Lynn Maser

Dissertations

Desorption electrospray ionization (DESI-MS) is an ambient ionization technique where the sample is analyzed directly from a surface with very minimal sample preparation under ambient conditions and follows ESI-like ionization mechanisms. DESI-MS has proven powerful in analyzing or imaging lipids and other small molecules directly from biological samples and even allows for subsequent histological staining and analyses. However, DESI-MS is less widely used for protein analysis due to a lack of sensitivity and the complex diversity of proteins in biological samples.

A major goal of this research has been to obtain new neurobiological knowledge by combining histology and mass spectrometry …


Development Of Novel Mass Spectrometric Methods For Reaction Screening, Oligosaccharide Detection, And Nitrosamine Quantitation, Qi Wang May 2022

Development Of Novel Mass Spectrometric Methods For Reaction Screening, Oligosaccharide Detection, And Nitrosamine Quantitation, Qi Wang

Dissertations

Benefitting from its high detection sensitivity and specificity, mass spectrometry (MS) has become a powerful technique in academia and industry. The aim of this dissertation study is to develop new mass spectrometric methods for organic reaction screening, detection of oligosaccharide/glycan in complex matrices, and nitrosamine absolute quantitation.

First, an electrochemistry/mass spectrometry (EC/MS) platform is built to generate an N-cyclopropylaniline radical cation electrochemically and to monitor its reactivity toward alkenes, which leads to the discovery of a new redox neutral reaction of intermolecular [3 + 2] annulation of N-cyclopropylanilines and alkenes. Net redox neutral electrosynthesis is quite rare in synthetic organic …


Investigation Of The Analytical Utility Of The Inductively Coupled Plasma Mass Spectrometer (Icp-Ms) For The Quantification Of Proteins Via Lanthanide Labeling, Caitlin Elizabeth Dunlap May 2022

Investigation Of The Analytical Utility Of The Inductively Coupled Plasma Mass Spectrometer (Icp-Ms) For The Quantification Of Proteins Via Lanthanide Labeling, Caitlin Elizabeth Dunlap

Undergraduate Honors Thesis Collection

The discovery and ability to provide an absolute concentration of biomarkers in the body can facilitate early diagnoses of diseases. This information can also be used for more accurate and unique treatments for those patients. While major advances in molecular mass spectrometry allows for a sensitive identification of these biomarkers, they are limited to only four orders of magnitude in their dynamic ranges. Due to this, detection and quantitation of low abundant proteins, which tend to make up these vital biomarkers, is very difficult. On the other hand, ICP-MS offers a wider dynamic range (up to 12 orders of magnitude) …


Characterizing The Effects Of Solvent And Analyte Properties On Ionization Efficiency By Novel Field-Free And Field-Enabled Ionization Techniques, Kinkini Udara Jayasundara Jan 2022

Characterizing The Effects Of Solvent And Analyte Properties On Ionization Efficiency By Novel Field-Free And Field-Enabled Ionization Techniques, Kinkini Udara Jayasundara

Graduate Theses, Dissertations, and Problem Reports

In recent years the mass spectrometry (MS) area of field and/or direct analysis has grown dramatically. As a result, field-portable and miniaturized mass spectrometers, introduced only a few years ago, are proliferating. A highly desired feature for field-portable MS, or in-field analysis, is the ability to use ionization techniques requiring very little sample preparation as well as an ability to generate the ions under ambient conditions. Recently, a new ambient ionization technique termed vibrating sharp-edge spray ionization (VSSI) has been introduced which overcomes the field-portable limitations of other spray-based methods including the requirements for auxiliary components (e.g., nebulizing gas and …


Capillary Electrophoresis: Method Development And Application In Biomolecule Analysis, Lindsay Marie Veltri Jan 2022

Capillary Electrophoresis: Method Development And Application In Biomolecule Analysis, Lindsay Marie Veltri

Graduate Theses, Dissertations, and Problem Reports

Abstract

Capillary Electrophoresis: Method Development and Application in Biomolecule Analysis

Lindsay Veltri

Biomolecule analysis is essential in disease diagnostics and the development of therapeutic agents. There is a vast array of methods available for biomolecule analysis, however, capillary electrophoresis is well-suited due to minimal sample consumption (~nanoliters of solution) and fast analysis times. In this report, capillary electrophoresis was used to analyze glycosylation of therapeutic proteins. Additionally, a capillary electrophoresis-mass spectrometry method is reported for the analysis of proteins.

Post-translation protein modifications like glycosylation, play an important in protein structure and function. Modifications of protein glycosylation can lead to improved …


Analysis Of Forensically Relevant Evidence Using Electrochemistry, Spectroscopy, And Mass Spectrometry Tools, Colby Edward Ott Jan 2022

Analysis Of Forensically Relevant Evidence Using Electrochemistry, Spectroscopy, And Mass Spectrometry Tools, Colby Edward Ott

Graduate Theses, Dissertations, and Problem Reports

Forensic science relies on the use of multiple techniques in the assessment of evidence to increase the accuracy and reliability of the results. However, with the rapidly changing drug landscape due to the introduction of novel psychoactive substances, many traditional screening methods are no longer sensitive or selective enough for use. Additionally, many screening methods such as chemical color tests are prone to false positive and negative results and are subjective. Therefore, the goal of this dissertation was to develop a novel analytical scheme that can provide a more efficient, rapid, and sensitive method that will facilitate adoption in the …


Electrochemical And Mass Spectrometry Methods For Identification Of Gunshot Residues (Gsr) In Forensic Investigations, Kourtney A. Dalzell Jan 2022

Electrochemical And Mass Spectrometry Methods For Identification Of Gunshot Residues (Gsr) In Forensic Investigations, Kourtney A. Dalzell

Graduate Theses, Dissertations, and Problem Reports

Gun violence continues to be one of most significant challenges straining the USA society causing thousands of human lives lost every year. In 2020 alone, firearm-related incidents including homicide, accidents, and suicides, reached a staggering number of over 43,000.1,2 With the increase in these types of incidents, several service areas in crime laboratories are heavily impacted by the number of cases run on a yearly basis. These include firearm examinations, gunshot residue (GSR) analysis, bullet hole identification, and shooting distance determination, which are crucial to support a criminal investigation and, overall, the justice system in our country. These areas …


Development And Applications Of Touch Chemistry Biometrics Analysis Of Latent Fingermarks By Maldi-Ms, Cameron M. Longo Jan 2022

Development And Applications Of Touch Chemistry Biometrics Analysis Of Latent Fingermarks By Maldi-Ms, Cameron M. Longo

Legacy Theses & Dissertations (2009 - 2024)

Fingerprint evidence has long been a pillar of forensic science and has been used for over a century as a means of identifying an individual. This is accomplished through the comparison of friction ridge patterns, which are inherently unique to each individual, and the practice of visualizing fingerprints and comparing them has become a well-studied field. While these techniques have been optimized and improved over time, they generally rely only on the physical pattern to provide information about the donor, and not the content of the fingerprint material itself. In the modern era, steps have been made to extract from …


Characterization Of Small Molecules And Ions By Atmospheric Pressure Ionization-Mass Spectrometry, Maleesha De Silva Dec 2021

Characterization Of Small Molecules And Ions By Atmospheric Pressure Ionization-Mass Spectrometry, Maleesha De Silva

Theses and Dissertations

Mass spectrometry (MS) has become a widely used technique for the characterization of a wide range of substances in diverse fields. The selection of appropriate ionization techniques, source parameters, charge carriers based on the analyte’s polarity is essential in MS as only the ions are detected. When using a soft ionization technique, single stage-MS at best provides only chemical composition; thus, tandem MS is needed to determine structural information and dissociation pathways. This dissertation focuses on the characterization of various small molecules and ions using different ionization techniques, charge carriers, and collision-induced dissociation (CID).

In Chapter II, commercially available ionic …


Mass Spectrometry Directed Pre-Clinical Studies Of Asthma Candidate Midd0301 And Its Analogs, Md Shadiqur Rashid Roni Dec 2021

Mass Spectrometry Directed Pre-Clinical Studies Of Asthma Candidate Midd0301 And Its Analogs, Md Shadiqur Rashid Roni

Theses and Dissertations

ABSTRACTMASS SPECTROMETRY DIRECTED PRE-CLINICAL STUDIES OF ASTHMA CANDIDATE MIDD0301 AND ITS ANALOGS by Md Shadiqur Rashid Roni The University of Wisconsin-Milwaukee, 2021 Under the Supervision of Professor Alexander (Leggy) Arnold

Asthma is one of the most prevalent global health problems. More than 25 million Americans are suffering from asthma and their symptoms especially in children are not well controlled with current medications. The current therapeutic options to control symptoms are limited and are commonly based on inhaled corticosteroids. There are several reasons for uncontrolled asthma symptoms that includes steroid resistance, improper use of inhalers and very few orally available medications. …


Characterization Of Biological Samples Using Multi-Modal Mass Spectrometry, Yarixa L. Cintron-Diaz Nov 2021

Characterization Of Biological Samples Using Multi-Modal Mass Spectrometry, Yarixa L. Cintron-Diaz

FIU Electronic Theses and Dissertations

There is a need for fast, accurate and cost-effective protocols capable of assessing biomolecules at the molecular level (e.g., proteins, lipids and metabolites) from biological specimens. Mass spectrometry (MS) based techniques have become the analytical gold standard for identification and characterization of biomarkers in biological samples. The high throughput and short analysis time scales enables to follow biological processes while providing detailed chemical and spatial characterization. One of the current challenges in biological MS, is the high molecular complexity, chemical diversity and dynamic range. In this dissertation, the use of multi-modal mass spectrometry workflows -mass spectrometry imaging and ion mobility …


Non-Target Analysis Using High-Resolution Mass Spectrometry To Characterize And Remediate Urban Waters, Brian Ng Nov 2021

Non-Target Analysis Using High-Resolution Mass Spectrometry To Characterize And Remediate Urban Waters, Brian Ng

FIU Electronic Theses and Dissertations

The first part of this dissertation will focus on the development of a simple, robust online solid phase extraction liquid chromatography high resolution mass spectrometry (SPE LC-HRMS) method followed by the use of computational software workflows for non-target analysis (NTA) of environmental samples (development). The benchmarks to assess reproducibility are not well defined for non-target analysis. Parameters to evaluate analytical performance, such as accuracy, precision and selectivity, are well defined for target analysis, but remain elusive for non-target screening analysis. In this study, quality control (QC) guidelines are proposed to assure reliable data in NTA methodologies using a simple …


Don't Sell Them Short, There's More To Bacterial Natural Products Than Antibiotics, Alison Clare Domzalski Sep 2021

Don't Sell Them Short, There's More To Bacterial Natural Products Than Antibiotics, Alison Clare Domzalski

Dissertations, Theses, and Capstone Projects

Recent genomic studies of microbiomes have revealed an overwhelming number of biosynthetic genes of unknown function. Most of these “cryptic” biosynthetic genes are not expressed in laboratory monocultures of individual microbes. Thus, there remains tremendous untapped potential for natural products discovery. Here we employ mixed microbial culture (MMC) as a simple yet powerful approach to awaken cryptic biosynthetic gene clusters. Our preliminary studies demonstrated that arrays of metabolites could be induced in MMCs upon environmental cues, such as surface adhesion. Using this system, we have screened, identified, and isolated bioactive bacterial metabolites, which were characterized structurally and biologically. Of the …


Mass Spectrometry Based Metabolomics And Lipidomics., Fang Yuan Aug 2021

Mass Spectrometry Based Metabolomics And Lipidomics., Fang Yuan

Electronic Theses and Dissertations

Metabolomics and lipidomics studies are important to understand living organisms at the molecular level. In this dissertation, I conducted various untargeted and targeted metabolomics and lipidomics studies using mass spectrometry based analytical platforms. Firstly, I investigated the androgen depletion effects on fecal metabolites in a mouse model of systemic lupus erythematosus and metabolite biomarkers for colorectal cancer using two-dimensional gas and liquid chromatography-mass spectrometry. Secondly, I investigated the relationship between gut microbiota-mediated resistance and susceptibility to malaria and the production of short-chain fatty acids using gas chromatography-mass spectrometry. Thirdly, I developed a high-throughput liquid chromatography-mass spectrometry method to profile long-chain …


Integrated Mass Spectrometry-Based Method In Protein Chemistry: Metal-Binding Protein And Integral Membrane Protein, Chunyang Guo May 2021

Integrated Mass Spectrometry-Based Method In Protein Chemistry: Metal-Binding Protein And Integral Membrane Protein, Chunyang Guo

Arts & Sciences Electronic Theses and Dissertations

Most biological processes are associated with protein catalysis. Characterizing protein structure, therefore, is crucial for understanding biological function. Mass spectrometry (MS)-based methods have emerged as a pivotal biophysical tool to interrogate protein structures; they can characterize protein-ligand/protein complexes that are refractory to conventional high-resolution means such as X-ray crystallography, Cryo-EM, and nuclear magnetic resonance (NMR) spectroscopy, in part owing to high molecular weight and significant flexibility. The integrated MS-based platform will provide topology and structural information of proteins from sketch to detail; native MS identifies protein complexes’ composition and stoichiometry; hydrogen-deuterium exchange MS (HDX-MS) detects the protein complexes’ dynamic change …


Mass Spectrometry-Based Strategies In Protein Higher Order Structure Analysis: Fundamentals And Applications In Protein-Ligand Interactions, Xiaoran Liu Jan 2021

Mass Spectrometry-Based Strategies In Protein Higher Order Structure Analysis: Fundamentals And Applications In Protein-Ligand Interactions, Xiaoran Liu

Arts & Sciences Electronic Theses and Dissertations

Protein ligand interaction is a fundamental question in biology and biochemistry, and many approaches including X-ray crystallography, nuclear magnetic resonance, cryogenic electron microscopy, mass spectroscopy (MS), infrared spectroscopy, circular dichroism, fluorescence spectroscopy and many others have been applied to address this question. Among these techniques, mass spectroscopy has the advantage of high throughput, low sample amount requirement, and mid-to-high spatial resolution. One of the MS-based approaches is protein footprinting, which utilizes labeling reagents to map the solvent accessible surface of the protein of interest thus deliver structural information. Irreversible labeling is represented by covalent labeling and radical labeling, in which …


Validation Of A Deployable Proteomic Assay For The Serological Screening Of Sexual Assault Samples, Catherine O'Sullivan Brown Jan 2021

Validation Of A Deployable Proteomic Assay For The Serological Screening Of Sexual Assault Samples, Catherine O'Sullivan Brown

Electronic Theses and Dissertations

Protein mass spectrometry (MS) has emerged as a technique to supplant traditional serological tests for body fluid identification. It was hypothesized that proteomic techniques would surpass the sensitivity and specificity of traditional serological techniques. An automated workflow coupled with protein MS has been developed for the confirmatory identification of five biological fluids. A developmental validation was completed, assessing parameters such as reproducibility, sensitivity, ion suppression, and limit of detection. Implementation was determined through tandem sample processing by MS, traditional serological tests, and standard DNA profiling methods. The MS approach offered superior detection limits while also providing true confirmatory results, producing …


Mass Spectral And Chemometric Analysis For The Detection And Identification Of Forensically Relevant Materials, Meghan Grace Appley Jan 2021

Mass Spectral And Chemometric Analysis For The Detection And Identification Of Forensically Relevant Materials, Meghan Grace Appley

Legacy Theses & Dissertations (2009 - 2024)

Forensic science is the application of science to the law which in and of itself covers a substantial number of disciplines. Many of these involve the detection and identification of materials using analytical techniques. Traditional analysis methods include microscopy, spectroscopy and mass spectrometry. The materials encountered by forensic practitioners are ever evolving, resulting in the need to develop new methods to complement conventional techniques to enhance the evidentiary value of the samples. The research presented here shows that novel methods including direct analysis in real time–high-resolution mass spectrometry (DART-HRMS), thermal desorption coupled with gas chromatography-mass spectrometry (TD-GC-MS), solid-phase microextraction (SPME) …


Application Of Direct Analysis In Real Time-High Resolution Mass Spectrometry To Genus- And Species-Level Differentiation And Identification Of Coral, Jessica Mary Hayes Jan 2021

Application Of Direct Analysis In Real Time-High Resolution Mass Spectrometry To Genus- And Species-Level Differentiation And Identification Of Coral, Jessica Mary Hayes

Legacy Theses & Dissertations (2009 - 2024)

Coral reefs are one of the most biologically diverse ecosystems, and the accurate identification of the species is essential for diversity assessment, species delimitation and conservation. Current species and genus determination approaches are time consuming, resource intensive and can be highly subjective. To explore the hypothesis that the small molecule profiles of coral are species and genus specific, and can be used as a rapid tool to catalogue, classify and identify coral genera and species, the small-molecule chemical fingerprints of coral belonging to the species Acanthastrea echinata, Catalaphyllia jardinei, Duncanopsammia axifuga, Echinopora lamellosa, Euphyllia divisa, Euphyllia paraancora, Euphyllia paradivisa, Galaxea …


Novel Applications Of Mass Spectrometry For Quantitation And Reaction Mechanism Elucidation, Pengyi Zhao Dec 2020

Novel Applications Of Mass Spectrometry For Quantitation And Reaction Mechanism Elucidation, Pengyi Zhao

Dissertations

Mass spectrometry (MS) has been growing as one of the most widely used tools in the field of analytical chemistry. Various applications have been developed to harness the high sensitivity and specificity of mass spectrometric analysis. In this dissertation, two major challenges are addressed. By developing mass spectrometric-based methods, absolute quantitation of proteins/peptides have been achieved. Elucidation of various reaction mechanisms are also enabled. These are the focuses of this dissertation.

In Chapters 2 to 4, a novel quantitation method is developed, titled as coulometric mass spectrometry (CMS). The strength of this method is that no reference standard or isotope-labeled …


Effects Of Oxidative Modifications On The Structure And Non-Canonical Functions Of Cytochrome C Studied By Mass Spectrometry, Victor Yin Sep 2020

Effects Of Oxidative Modifications On The Structure And Non-Canonical Functions Of Cytochrome C Studied By Mass Spectrometry, Victor Yin

Electronic Thesis and Dissertation Repository

The peroxidase activity of the mitochondrial protein cytochrome c (cyt c) plays a critical role in triggering programmed cell death, or apoptosis. However, the native structure of cyt c should render this activity impossible due to the lack of open iron coordination sites at its heme cofactor. Despite its key biological importance, the molecular mechanisms underlying this structure-function mismatch remain enigmatic. The work detailed in this dissertation fills this knowledge gap by using mass spectrometry (MS) to decipher the central role that protein oxidative modifications and their associated structural changes play in activating the peroxidase function of cyt c …