Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

PDF

Biochemistry

Mass spectrometry

Institution
Publication Year
Publication
Publication Type

Articles 1 - 30 of 67

Full-Text Articles in Life Sciences

Fbg Αc 389 – 402 Modulates Factor Xiii Crosslinking In The Fibrinogen Αc Region., Francis Dean Orlina Ablan Aug 2023

Fbg Αc 389 – 402 Modulates Factor Xiii Crosslinking In The Fibrinogen Αc Region., Francis Dean Orlina Ablan

Electronic Theses and Dissertations

Fibrinogen (Fbg) is a coagulation protein critical for clot formation. Coagulation Factor XIII (FXIII) is a calcium-dependent transglutaminase that crosslinks reactive glutamines (Q) and lysines (K) between fibrin and other anti-fibrinolytic proteins. In the presence of Ca2+, FXIII could be activated non-proteolytically (FXIII-A°), or proteolytically by thrombin (FXIII-A*). Significant increases in clot stability and red blood cell retention are linked to FXIII activity in the fibrinogen αC region (Fbg Aα 221 – 610). This region contains several FXIII-reactive glutamines and lysines, as well as a binding site for FXIII-A* (Fbg αC 389 – 402) that includes a key …


Probing Amyloid-Beta Protein Structure And Dynamics With A Selective Antibody, Shikha Grover Feb 2023

Probing Amyloid-Beta Protein Structure And Dynamics With A Selective Antibody, Shikha Grover

Dissertations

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder. The AD brain is characterized by significant neuronal loss and accumulation of insoluble fibrillar amyloid-β protein (Aβ) plaques and tau protein neurofibrillary tangles in the brain. However, over the last decade, many studies have shown that the neurodegenerative effect of Aβ may in fact be caused by various soluble oligomeric forms as opposed to the insoluble fibrils. Furthermore, the data suggest that a pre-fibrillar aggregated form, termed protofibrils, mediates direct neurotoxicity, and triggers a robust neuroinflammatory response.

Antibodies targeting the various conformation of Aβ are important therapeutic agents to prevent the progression …


Quantifying Protein Quality To Understand Protein Homeostasis (Supplemental Data), Hsien-Jung Lavender Lin Jul 2022

Quantifying Protein Quality To Understand Protein Homeostasis (Supplemental Data), Hsien-Jung Lavender Lin

ScholarsArchive Data

This data set includes the supplementary data for chpaters 3 and 4 in the dissertation Quantifying Protein Quality to Understand Protein Homeostasis. It includes various excel worksheets that were used to generate the data reported in the dissertation. We make this data available to the public so anyone who wants to reproduce the results has the resources and access to other perspectives that weren't discussed in depth in the dissertation. Chapter 3 used mass-spectrometry to quantify the surface accessibility differences in human serum albumin (HSA)between patients with and without rheumatoid arthritis (RA). We found certain residues are less reactive …


A Glass Bead Semi‑Hydroponic System For Intact Maize Root Exudate Analysis And Phenotyping, Martha G. Lopez-Guerrero, Peng Wang, Felicia Phares4, Daniel P. Schachtman, Sophie Alvarez, Karin Van Dijk Mar 2022

A Glass Bead Semi‑Hydroponic System For Intact Maize Root Exudate Analysis And Phenotyping, Martha G. Lopez-Guerrero, Peng Wang, Felicia Phares4, Daniel P. Schachtman, Sophie Alvarez, Karin Van Dijk

Department of Biochemistry: Faculty Publications

Background: Although there have been numerous studies describing plant growth systems for root exudate collection, a common limitation is that these systems require disruption of the plant root system to facilitate exudate collection. Here, we present a newly designed semi-hydroponic system that uses glass beads as solid support to simulate soil impedance, which combined with drip irrigation, facilitates growth of healthy maize plants, collection and analysis of root exudates, and phenotyping of the roots with minimal growth disturbance or root damage.

Results: This system was used to collect root exudates from seven maize genotypes using water or 1 mM CaCl …


Microbial Labilization And Diversification Of Pyrogenic Dissolved Organic Matter, Aleksandar I. Goranov, Andrew S. Wozniak, Kyle W. Bostick, Andrew R. Zimmerman, Siddhartha Mitra, Patrick G. Hatcher Jan 2022

Microbial Labilization And Diversification Of Pyrogenic Dissolved Organic Matter, Aleksandar I. Goranov, Andrew S. Wozniak, Kyle W. Bostick, Andrew R. Zimmerman, Siddhartha Mitra, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

With the increased occurrence of wildfires around the world, interest in the chemistry of pyrogenic organic matter (pyOM) and its fate in the environment has increased. Upon leaching from soils by rain events, significant amounts of dissolved pyOM (pyDOM) enter the aquatic environment and interact with microbial communities that are essential for cycling organic matter within the different biogeochemical cycles. To evaluate the biodegradability of pyDOM, aqueous extracts of laboratory-produced biochars were incubated with soil microbes, and the molecular changes to the composition of pyDOM were probed using ultrahigh-resolution mass spectrometry (Fourier transform–ion cyclotron resonance–mass spectrometry). Given that solar irradiation …


Rnp Granules In Toxoplasma Gondii: Function And Formation, Scott Roscoe Jan 2022

Rnp Granules In Toxoplasma Gondii: Function And Formation, Scott Roscoe

Electronic Theses and Dissertations

Toxoplasma gondii is an obligate intracellular parasite capable of infecting mammals, birds, reptiles, and fish. T. gondii only undergoes sexual reproduction in a feline host. In all other organisms the parasite reproduces asexually, either as fast growing tachyzoites or slow growing bradyzoites. Bradyzoites form latent cysts inside the host cell that can lay dormant for years and convert back to tachyzoites when the host’s immune system becomes weakened. Tachyzoites rapidly replicate in the host cell, eventually causing it to lyse. While extracellular, tachyzoites repress their own translation by phosphorylating the eukaryotic initiation factor eIF2α and form microscopically visible aggregates of …


The Study Of The Structure And Dynamics Of Parkin Activation, Elaine Aisha Freeman Dec 2021

The Study Of The Structure And Dynamics Of Parkin Activation, Elaine Aisha Freeman

Electronic Thesis and Dissertation Repository

Parkin is an RBR E3 ubiquitin ligase that has been implicated in both sporadic and familial Parkinson’s disease. Upon mitochondrial damage, parkin is activated step-wise to recruit and ligate ubiquitin to a substrate on the outer mitochondrial membrane. Disruption of this activation and ligation cascade is hypothesized to result in neuronal death related to Parkinson’s disease.

While structures of parkin for a number of these activation states exist, it is important to note they are not of full-length human parkin. These structures are often truncated and come from various non-human species to eliminate important, yet hard to quantify structural elements. …


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 …


Identification Of Fluoxetine-Sert Interactions And Apo-Sert Studies Via Crosslinking Mass Spectrometry, Elizabeth Castellano Aug 2021

Identification Of Fluoxetine-Sert Interactions And Apo-Sert Studies Via Crosslinking Mass Spectrometry, Elizabeth Castellano

Electronic Theses and Dissertations

The serotonin transporter (SERT) is a member of the neurotransmitter sodium symporter family of transporters. SERT controls the magnitude and duration of serotonergic neurotransmission by facilitating the reuptake of serotonin back into the pre-synaptic neuron and is thus a target for antidepressants. Selective serotonin re-uptake inhibitors (SSRIs) such as fluoxetine, are commonly prescribed to treat depression. SSRIs act by blocking reuptake and prolonging serotonin signaling. However, significant problems regarding selectivity and mechanisms of action of these drugs remain unresolved. The structures of SERT and related transporters have been determined and serve as useful structural models. However, they are typically mutated …


Uncovering The Ubiquitin Ligase Activity And Substrates Of The Human C-Terminal To Lish (Ctlh) Complex, Matthew E.R. Maitland Apr 2021

Uncovering The Ubiquitin Ligase Activity And Substrates Of The Human C-Terminal To Lish (Ctlh) Complex, Matthew E.R. Maitland

Electronic Thesis and Dissertation Repository

Ubiquitination is the transfer of a ubiquitin molecule to protein substrates by the sequential actions of E1 activating enzymes, E2 conjugating enzymes, and E3 ligases. It is a post-translational modification that controls the fate and function of the substrate protein. Substrate specificity in the ubiquitination reaction is conferred by the E3 ligases. Sequence homology suggests the human C-terminal to LisH (CTLH) complex could be an E3 ligase; however, very little is known about this complex. In this thesis, I characterize the human CTLH complex as a multi-subunit E3 ligase and define its activity, structure, and substrates. I demonstrate that the …


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 …


A Proteomic Analysis Of Corydoras Sterbai Secretions And Tissues, Erik Powell Wictor Jan 2020

A Proteomic Analysis Of Corydoras Sterbai Secretions And Tissues, Erik Powell Wictor

University of the Pacific Theses and Dissertations

Defensive mechanisms vary widely in the animal kingdom ranging from physical defenses like spines to chemical defenses such as toxins. Toxins in these secretions and tissues can fluctuate from enzymes to lipids to uncharacterized chemicals. Next generation -omics technology and mass spectrometry are extremely important in analyzing these samples because of their ability to distinguish minute amounts of toxic substance within a complicated sample. The goal of this experiment was to look at secretions and tissues from Corydoras sterbai. All samples in this study were proteolyzed using a mixture of Trypsin and Lys-C, fractionated, and run through nanoLC-MS/MS analysis using …


Protein/Peptide Characterization Using Mass Spectrometry And Molecular Dynamics Simulations, Ahmad Kiani Karanji Jan 2020

Protein/Peptide Characterization Using Mass Spectrometry And Molecular Dynamics Simulations, Ahmad Kiani Karanji

Graduate Theses, Dissertations, and Problem Reports

Mass spectrometry (MS) based-techniques and molecular dynamics (MD) simulations have been used to characterize protein/peptide structure as well as their interactions with lipid vesicles and detergents. Chapter 1 introduces an introduction to the concepts and tools that were used in this work. In Chapter 2, the dominant gas-phase conformer of [M+3H]3+ ions of the model peptide Acetyl-PSSSSKSSSSKSSSSKSSSSK are examined with ion mobility spectrometry (IMS), gas-phase hydrogen deuterium exchange (HDX), and mass spectrometry (MS) techniques. This section furthers the development of a protein structural prediction tool by providing information about gas-phase ion conformers of two model peptides having different solution conformational …


Systematic Identification Of The Lysine Methylome Using Methyllysine Binding Domains, Wen Qin Oct 2019

Systematic Identification Of The Lysine Methylome Using Methyllysine Binding Domains, Wen Qin

Electronic Thesis and Dissertation Repository

Post-translational modifications (PTM) are vital regulators of protein function and homeostasis. The role of dynamic regulations of non-histone lysine methylated proteins (NHKMP) recently began to be recognized in DNA damage repair, apoptosis and transcriptional pathways. My goal was to identify components of the NHKMP network to understand its importance in a healthy versus diseased cellular state. I used membrane peptide arrays to systematically characterize nine naturally occurring lysine methyl binding domains (KMBD). Five KMBDs were chosen based on their overlapping specificities to achieve maximum coverage of lysine methylated peptides. These five KMBDs was used to enrich for methylated lysine peptides …


Ni Site Structure And Function In Biological Sensing And Enzyme Activity, Hsin-Ting Huang Jul 2019

Ni Site Structure And Function In Biological Sensing And Enzyme Activity, Hsin-Ting Huang

Doctoral Dissertations

Ni(II) is one of the important cofactors involved in various enzyme functions. For organisms utilizing Ni(II), a regulation system is required to maintain Ni(II) homeostasis and prevent toxicity. The focus of this dissertation is on investigating the relationship between the Ni(II) site structure and the function of proteins, a Ni(II) sensor and a Ni(II) enzyme. RcnR, a Ni(II)/Co(II) sensor in E. coli, controls the expression of the Ni(II)/Co(II) exporter proteins, RcnAB. Due to the lack of structural information, the mechanism of metal induced allosteric regulation and metal selection is not fully elucidated. Results presented here show that binding of …


Mass Spectrometry-Based Proteomics Analysis Of Bioactive Proteins In Emd That Modulate Adhesion Of Gingival Fibroblast To Improve Bio-Integration Of Dental Implants, David Zuanazzi Machado Jr Mar 2019

Mass Spectrometry-Based Proteomics Analysis Of Bioactive Proteins In Emd That Modulate Adhesion Of Gingival Fibroblast To Improve Bio-Integration Of Dental Implants, David Zuanazzi Machado Jr

Electronic Thesis and Dissertation Repository

Titanium implants are used in dental practice to replace damaged or lost teeth. The implant needs to integrate with the surrounding gingiva to protect it against bacterial invasion that leads to implant loss. The biointegration is dependent on the implant surface that interacts with proteins from biological fluids to modulate tissues response. Tailoring the surface with specific proteins from the enamel matrix derivative (EMD) would be beneficial to improve the implant-gingiva interface since EMD can affect various cells including gingival fibroblasts. A surface-affinity approach using three different titanium surfaces and saliva was utilized as a model in combination with tandem …


Amino Acids Profiling For The Diagnosis Of Metabolic Disorders, Yana Sandlers Jan 2019

Amino Acids Profiling For The Diagnosis Of Metabolic Disorders, Yana Sandlers

Chemistry Faculty Publications

Inborn errors of metabolism (IEM) represent a group of inherited diseases in which genetic defect leads to the block on a metabolic pathway, resulting in a single enzyme dysfunction. As a downstream consequence of the residual or full loss of the enzymatic activity, there is an accumulation of toxic metabolites in the proximity of the metabolic block and/or a deficiency of an essential metabolic product which leads to the clinical presentation of the disease. While individually IEMs are rare, a collectively estimated incidence of metabolic inherited disorders is 1:800. The genetic basis of IEMs can involve abnormalities such as point …


Evaluating Methods Of Obtaining Male Pheromone From Hymenochirus Sp. Using Analytical Chemistry, Vincent Wing-Kun Leung Jan 2019

Evaluating Methods Of Obtaining Male Pheromone From Hymenochirus Sp. Using Analytical Chemistry, Vincent Wing-Kun Leung

University of the Pacific Theses and Dissertations

Male Hymenochirus sp. frogs are known to release pheromone that attracts females of the same species. Four methods for collecting secretions containing pheromone in Hymenochirus sp. were tested: norepinephrine injection, gonadotropin-releasing hormone injection, homogenization of gland tissue, and electrostimulation of the skin over the breeding gland area. The samples collected were analyzed using high-performance liquid chromatography (HPLC) and mass spectrometry. The HPLC chromatograph for the male norepinephrine sample contained a peak at 6.4 min that was not in the female norepinephrine sample HPLC chromatograph. The male norepinephrine sample mass spectrum had a peak of m/z 292.0 not in the female …


The First In Vivo Human Methionine Sulfide Proteome And The Impact Of Smoking, Abdullah Qassab Dec 2018

The First In Vivo Human Methionine Sulfide Proteome And The Impact Of Smoking, Abdullah Qassab

Graduate Theses and Dissertations

Reactive oxygen species are naturally generated within the human body and they are known to modulate signaling pathway and mediate other physiological activities. However, excessive generation of ROS and the inability of body defense system in detoxifying them results in the so called “oxidative stress”. Methionine has powerful antioxidant properties due to the presence of electronegative sulfur in its structure. Therefore, Met is readily oxidized, and methionine sulfoxide has been linked to several pathological conditions.

The urinary proteome is an attractive candidate for the discovery of biomarkers to diagnose and classify health conditions because of the non-invasive collection procedure. However, …


Combining Mass Spectrometry And Nmr Improves Metabolite Detection And Annotation, Fatema Bhinderwala, Nishikant Wase, Concetta Dirusso, Robert Powers Nov 2018

Combining Mass Spectrometry And Nmr Improves Metabolite Detection And Annotation, Fatema Bhinderwala, Nishikant Wase, Concetta Dirusso, Robert Powers

Department of Biochemistry: Faculty Publications

Despite inherent complementarity, nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS) are routinely separately employed to characterize metabolomics samples. More troubling is the erroneous view that metabolomics is better served by exclusively utilizing MS. Instead, we demonstrate the importance of combining NMR and MS for metabolomics by using small chemical compound-treatments of Chlamydomonas reinhardtii as an illustrative example. A total of 102 metabolites were detected (82 by GC-MS, 20 by NMR and 22 by both techniques). Out of these 47 metabolites of interest were identified, where 14 metabolites were uniquely identified by NMR and 16 metabolites were uniquely identified …


Bayesian Analytical Approaches For Metabolomics : A Novel Method For Molecular Structure-Informed Metabolite Interaction Modeling, A Novel Diagnostic Model For Differentiating Myocardial Infarction Type, And Approaches For Compound Identification Given Mass Spectrometry Data., Patrick J. Trainor Aug 2018

Bayesian Analytical Approaches For Metabolomics : A Novel Method For Molecular Structure-Informed Metabolite Interaction Modeling, A Novel Diagnostic Model For Differentiating Myocardial Infarction Type, And Approaches For Compound Identification Given Mass Spectrometry Data., Patrick J. Trainor

Electronic Theses and Dissertations

Metabolomics, the study of small molecules in biological systems, has enjoyed great success in enabling researchers to examine disease-associated metabolic dysregulation and has been utilized for the discovery biomarkers of disease and phenotypic states. In spite of recent technological advances in the analytical platforms utilized in metabolomics and the proliferation of tools for the analysis of metabolomics data, significant challenges in metabolomics data analyses remain. In this dissertation, we present three of these challenges and Bayesian methodological solutions for each. In the first part we develop a new methodology to serve a basis for making higher order inferences in metabolomics, …


Examining Shsp-Substrate Capture And Chaperone Network Coordination Through Cross-Linking, Keith Ballard Jul 2018

Examining Shsp-Substrate Capture And Chaperone Network Coordination Through Cross-Linking, Keith Ballard

Doctoral Dissertations

Small heat shock proteins (sHSPs) and related α-crystallins are virtually ubiquitous, ATP-independent molecular chaperones linked to protein misfolding diseases. They comprise a conserved core α-crystallin domain (ACD) flanked by an evolutionarily variable N-terminal domain (NTD) and semi-conserved C-terminal extension/domain (CTD). They are capable of binding up to an equal mass of unfolding protein, forming large, heterogeneous sHSP-substrate complexes that coordinate with ATP-dependent chaperones for refolding. To derive common features of sHSP-substrate recognition, I compared the chaperone activity and specific sHSP-substrate interaction sites for three different sHSPs from Arabidopsis (At17.6B), pea (Ps18.1) and wheat (Ta16.9), for which the atomic solution-state structures …


Detection Of Semi-Polar Vitamins And Nutrients In Biological Samples, Jennifer Janovick Jan 2018

Detection Of Semi-Polar Vitamins And Nutrients In Biological Samples, Jennifer Janovick

Williams Honors College, Honors Research Projects

Metabolomics is used to examine metabolite fluctuations in biological systems and enables the diagnosis of metabolic disorders and the identification of new therapeutic targets.1 Liquid chromatography-mass spectrometry (LC-MS) was utilized to develop a new method using a T3 column to separate small molecule nutrients and vitamins in a tissue sample. Initial tests of column performance used standard solutions; the amount of metabolites identified and the elution profile of these metabolites was examined. Both the standard solution and sample of brain tissue were tested with the final method developed. Six metabolites were identified in the standard and 31 were identified …


Mass Spectrometry-Based Structural Proteomics: Methodology And Application Of Fast Photochemical Oxidation Of Proteins (Fpop), Ben Niu Aug 2017

Mass Spectrometry-Based Structural Proteomics: Methodology And Application Of Fast Photochemical Oxidation Of Proteins (Fpop), Ben Niu

Arts & Sciences Electronic Theses and Dissertations

The dissertation will be solely focused on using mass spectrometry to characterize protein high order structures (HOS), it emphasizes the use of hydroxyl radical footprinting (FPOP) coupled to bottom-up MS approach. A detailed background information about FPOP, and the corresponding method developments as well as applications will be covered.

The first chapter will be a comprehensive review regarding the FPOP. Following this, chapter 2, 3, and 4 will be focused on the method developments. Chapter 2 describes an isotope dilution GC-MS method to quantitate OH radicals in FPOP; chapter 3 describes the incorporation of Leu-enkephalin as reporter peptide for a …


Characterizing Reactive Glutamines In Fibrinogen And Elucidating Factor Xiii Substrate Specificity., Kelly Njine Mouapi Aug 2017

Characterizing Reactive Glutamines In Fibrinogen And Elucidating Factor Xiii Substrate Specificity., Kelly Njine Mouapi

Electronic Theses and Dissertations

Fibrinogen is the most abundant protein involved in blood coagulation and has been associated with many pathological implications in cardiovascular disease. At the final stages of blood clot formation, the transglutaminase Factor XIIIa introduces γ-glutamyl-ε-lysinyl covalent bonds between reactive glutamines and lysines in fibrin, which results in a tighter clot network that is resistant to fibrinolysis. Factor XIIIa crosslinks specific reactive glutamines on fibrinogen, selecting more reactive glutamines in the αC region of fibrinogen than any other chain. Although crosslinking pairs in the αC region have been identified, little is known about the extent of crosslinking and the role played …


Biochemical Characterization Of Arsi: A Novel C-As Lyase For Degradation Of Environmental Organoarsenicals, Shashank Suryakant Pawitwar Jun 2017

Biochemical Characterization Of Arsi: A Novel C-As Lyase For Degradation Of Environmental Organoarsenicals, Shashank Suryakant Pawitwar

FIU Electronic Theses and Dissertations

Organoarsenicals such as methylarsenical methylarsenate (MAs(V)) and aromatic arsenicals including roxarsone (4-hydroxy-3-nitrophenylarsenate or Rox(V)) have been extensively used as an herbicide and growth enhancers in animal husbandry, respectively. They undergo environmental degradation to more toxic inorganic arsenite (As(III)) that contaminates crops and drinking water. We previously identified a bacterial gene (arsI) responsible for aerobic MAs(III) demethylation. The gene product, ArsI, is a Fe(II)-dependent extradiol dioxygenase that cleaves the carbon-arsenic (C-As) bond in MAs(III) and trivalent aromatic arsenicals. The objective of this study was to elucidate the ArsI mechanism. Using isothermal titration calorimetry, we determined the dissociation constants (Kd) and ligand-to-protein …


Mapping Analyte-Signal Relations In Lc-Ms Based Untargeted Metabolomics, Nathaniel Guy Mahieu May 2017

Mapping Analyte-Signal Relations In Lc-Ms Based Untargeted Metabolomics, Nathaniel Guy Mahieu

Arts & Sciences Electronic Theses and Dissertations

The goal of untargeted metabolomics is to profile metabolism by measuring as many metabolites as possible. A major advantage of the untargeted approach is the detection of unexpected or unknown metabolites. These metabolites have chemical structures, metabolic pathways, or cellular functions that have not been previously described. Hence, they represent exciting opportunities to advance our understanding of biology. This beneficial approach, however, also adds considerable complexity to the analysis of metabolomics data - an individual signal cannot be readily identified as a unique metabolite. As such, a major challenge faced by the untargeted metabolomic workflow is extracting the analyte content …


Reactivity Of Ketyl And Acetyl Radicals From Direct Solar Actinic Photolysis Of Aqueous Pyruvic Acid, Alexis J. Eugene, Marcelo I. Guzman Mar 2017

Reactivity Of Ketyl And Acetyl Radicals From Direct Solar Actinic Photolysis Of Aqueous Pyruvic Acid, Alexis J. Eugene, Marcelo I. Guzman

Chemistry Faculty Publications

The variable composition of secondary organic aerosols (SOA) contributes to the large uncertainty for predicting radiative forcing. A better understanding of the reaction mechanisms leading to aerosol formation such as for the photochemical reaction of aqueous pyruvic acid (PA) at λ ≥ 305 nm can contribute to constrain these uncertainties. Herein, the photochemistry of aqueous PA (5-300 mM) continuously sparged with air is re-examined in the laboratory under comparable irradiance at 38° N at noon on a summer day. Several analytical methods are employed to monitor the time series of the reaction, including (1) the derivatization of carbonyl (C═O) functional …


Quantitative Proteomic Characterization Of Cx-4945, A Clinical Stage Inhibitor Of Protein Kinase Ck2, Adam J. Rabalski Feb 2017

Quantitative Proteomic Characterization Of Cx-4945, A Clinical Stage Inhibitor Of Protein Kinase Ck2, Adam J. Rabalski

Electronic Thesis and Dissertation Repository

Protein phosphorylation is controlled by protein kinases, and represents a critical signaling mechanism involved in the regulation of fundamental biological processes. Furthermore, the aberrant regulation of kinase activity is implicated in diseases such as cancer and has resulted in efforts to target kinases therapeutically. Protein kinase CK2, although frequently considered constitutively active, has emerged as a clinical target on the basis of its altered expression in different types of human cancers and its regulatory participation in multiple biological processes. In fact, CX-4945, a small molecule ATP-competitive inhibitor of CK2 has advanced to clinical trial and has been widely used to …