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Articles 31 - 60 of 73

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

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, …


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 …


Cell Division Regulation In Staphylococcus Aureus, Catherine M. Spanoudis Oct 2017

Cell Division Regulation In Staphylococcus Aureus, Catherine M. Spanoudis

USF Tampa Graduate Theses and Dissertations

Cell division is a fundamental biological process that occurs in all kingdoms of life. Our understanding of cell division in bacteria stems from studies in the rod-shaped model organisms: Gram-negative Escherichia coli and Gram-positive Bacillus subtilis. The molecular underpinnings of cell division regulation in non-rod-shaped bacteria remain to be studied in detail. Rod-shaped bacteria possess many positive and negative regulatory proteins that are essential to the proper placement of the division septa and ultimately the production of two identical daughter cells, many of which are absent in cocci. Given that essential cell division proteins are attractive antibacterial drug targets, it …


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 …


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 …


Mass Spectrometric Analysis And Machine Learning Enable Microorganism Classification Based On Rna Posttranscriptional Modifications, Colin Christopher Aldrich Jan 2017

Mass Spectrometric Analysis And Machine Learning Enable Microorganism Classification Based On Rna Posttranscriptional Modifications, Colin Christopher Aldrich

Legacy Theses & Dissertations (2009 - 2024)

RNA post-transcriptional modifications (PTMs) are dynamic features that can be up- or down-regulated by the health and metabolic state of a cell. These covalent modifications are installed and removed on RNA nucleosides by enzymes controlled by the activation and deactivation of specific genes. The goal of this research was to demonstrate that RNA PTMs can serve as a unique feature for the classification/identification of microorganisms. We utilized a scheme based on electrospray ionization mass spectrometry (ESI-MS) to obtain global PTM profiles from total RNA extracted from various microorganisms in optimal growth conditions as well as Salmonella typhimurium (S. typhimurium) spiked …


Further Development Of Raman Spectroscopy For Body Fluid Investigation : Forensic Identification, Limit Of Detection, And Donor Characterization, Claire K. Muro Jan 2017

Further Development Of Raman Spectroscopy For Body Fluid Investigation : Forensic Identification, Limit Of Detection, And Donor Characterization, Claire K. Muro

Legacy Theses & Dissertations (2009 - 2024)

The challenges to forensic body fluid analysis have placed limitations on the type of information that investigators can acquire and how that information can be collected. In recent years, Raman spectroscopy has proven itself useful for characterizing body fluids. In 2008, a large-scale investigation was undertaken to explore the use of Raman spectroscopy as a means of identifying body fluids. This work resulted in multidimensional Raman spectroscopic signatures for the five main body fluids: semen, peripheral blood, saliva, vaginal fluid, and sweat. These studies were incredibly successful and created the foundation for years of continued research. Accordingly, the studies included …


Oxidative Stress, Metabolomics Profiling, And Mechanism Of Local Anesthetic Induced Cell Death In Yeast, Cory Honsinger Thomas Boone, Ryan A. Grove, Dana Adamcova, Javier Seravalli, Jiri Adamec Jan 2017

Oxidative Stress, Metabolomics Profiling, And Mechanism Of Local Anesthetic Induced Cell Death In Yeast, Cory Honsinger Thomas Boone, Ryan A. Grove, Dana Adamcova, Javier Seravalli, Jiri Adamec

Department of Biochemistry: Faculty Publications

The World Health Organization designates lidocaine as an essential medicine in healthcare, greatly increasing the probability of human exposure. Its use has been associated with ROS generation and neurotoxicity. Physiological and metabolomic alterations, and genetics leading to the clinically observed adverse effects have not been temporally characterized. To study alterations that may lead to these undesirable effects, Saccharomyces cerevisiae grown on aerobic carbon sources to stationary phase was assessed over 6 h. Exposure of an LC50 dose of lidocaine, increased mitochondrial depolarization and ROS/RNS generation assessed using JC-1, ROS/RNS specific probes, and FACS. Intracellular calcium also increased, assessed by …


Metabolic Investigations Of The Molecular Mechanisms Associated With Parkinson’S Disease, Robert Powers, Shulei Lei, Annadurai Anandhan, Darrell D. Marshall, Bradley Worley, Ronald Cerny, Eric D. Dodds, Yuting Huang, Mihalis I. Panayiotidis, Aglaia Pappa, Rodrigo Franco Jan 2017

Metabolic Investigations Of The Molecular Mechanisms Associated With Parkinson’S Disease, Robert Powers, Shulei Lei, Annadurai Anandhan, Darrell D. Marshall, Bradley Worley, Ronald Cerny, Eric D. Dodds, Yuting Huang, Mihalis I. Panayiotidis, Aglaia Pappa, Rodrigo Franco

Robert Powers Publications

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by fibrillar cytoplasmic aggregates of α-synuclein (i.e., Lewy bodies) and the associated loss of dopaminergic cells in the substantia nigra. Mutations in genes such as α -synuclein (SNCA) account for only 10% of PD occurrences. Exposure to environmental toxicants including pesticides and metals (e.g., paraquat (PQ) and manganese (Mn)) is also recognized as an important PD risk factor. Thus, aging, genetic alterations, and environmental factors all contribute to the etiology of PD. In fact, both genetic and environmental factors are thought to interact in the promotion of idiopathic PD, but the mechanisms …


Metagomics: A Web-Based Tool For Peptide-Centric Functional And Taxonomic Analysis Of Metaproteomics Data, Michael Riffle, Damon H. May, Emma Timmins-Schiffman, Molly P. Mikan, Daniel Jaschob, William S. Noble, Brook L. Nunn Jan 2017

Metagomics: A Web-Based Tool For Peptide-Centric Functional And Taxonomic Analysis Of Metaproteomics Data, Michael Riffle, Damon H. May, Emma Timmins-Schiffman, Molly P. Mikan, Daniel Jaschob, William S. Noble, Brook L. Nunn

OES Faculty Publications

Metaproteomics is the characterization of all proteins being expressed by a community of organisms in a complex biological sample at a single point in time. Applications of metaproteomics range from the comparative analysis of environmental samples (such as ocean water and soil) to microbiome data from multicellular organisms (such as the human gut). Metaproteomics research is often focused on the quantitative functional makeup of the metaproteome and which organisms are making those proteins. That is: What are the functions of the currently expressed proteins? How much of the metaproteome is associated with those functions? And, which microorganisms are expressing the …


Comparative Analysis Of In Situ Fibronectin Using Tof-Sims, Spi-Ms, And Dropdesi-Ms In A Microfluidic Reactor, Shannon Fasing, Xiao-Ying Yu, Juan Yao, Jiachao Yu Aug 2016

Comparative Analysis Of In Situ Fibronectin Using Tof-Sims, Spi-Ms, And Dropdesi-Ms In A Microfluidic Reactor, Shannon Fasing, Xiao-Ying Yu, Juan Yao, Jiachao Yu

STAR Program Research Presentations

Fibronectin is an important biomolecule due to its role in cell differentiation, growth, kinesis, and adhesion. Such biological responses are mediated through membrane recognition and signaling; where fibronectin is found. Studying the outer molecular surface of fibronectin allows deeper insight into the microbiological reactions that occur during these processes. In situ mass spectrometry analysis in aqueous solution accurately represents fibronectin’s chemical components, made possible by a vacuum compatible microfluidic reactor, SALVI (System for Analysis at the Liquid Vacuum Interface). SALVI was paired with the analytical tools: time-of-flight secondary ion mass spectrometer (ToF-SIMS), single photon ionization mass spectrometer (SPI-MS) and drop …


Quantitative Mass Spectrometry Reveals Changes In Histone H2b Variants As Cells Undergo Inorganic Arsenic-Mediated Cellular Transformation, Matthew Rea, Tingting Jiang, Rebekah Eleazer, Meredith Eckstein, Alan G. Marshall, Yvonne N. Fondufe-Mittendorf May 2016

Quantitative Mass Spectrometry Reveals Changes In Histone H2b Variants As Cells Undergo Inorganic Arsenic-Mediated Cellular Transformation, Matthew Rea, Tingting Jiang, Rebekah Eleazer, Meredith Eckstein, Alan G. Marshall, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

Exposure to inorganic arsenic, a ubiquitous environmental toxic metalloid, leads to carcinogenesis. However, the mechanism is unknown. Several studies have shown that inorganic arsenic exposure alters specific gene expression patterns, possibly through alterations in chromatin structure. While most studies on understanding the mechanism of chromatin-mediated gene regulation have focused on histone post-translational modifications, the role of histone variants remains largely unknown. Incorporation of histone variants alters the functional properties of chromatin. To understand the global dynamics of chromatin structure and function in arsenic-mediated carcinogenesis, analysis of the histone variants incorporated into the nucleosome and their covalent modifications is required. Here …


Direct Analysis In Real Time (Dart) Of An Organothiophosphate At Ultrahigh Resolution By Fourier Transform Ion Cyclotron Resonance Mass Spectrometry And Tandem Mass Spectrometry, Laszlo Prokai, Stanley M. Stevens Jr. Jan 2016

Direct Analysis In Real Time (Dart) Of An Organothiophosphate At Ultrahigh Resolution By Fourier Transform Ion Cyclotron Resonance Mass Spectrometry And Tandem Mass Spectrometry, Laszlo Prokai, Stanley M. Stevens Jr.

Molecular Biosciences Faculty Publications

Direct analysis in real time (DART) is a recently developed ambient ionization technique for mass spectrometry to enable rapid and sensitive analyses with little or no sample preparation. After swab-based field sampling, the organothiophosphate malathion was analyzed using DART-Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry (MS) and tandem mass spectrometry (MS/MS). Mass resolution was documented to be over 800,000 in full-scan MS mode and over 1,000,000 for an MS/MS product ion produced by collision-induced dissociation of the protonated analyte. Mass measurement accuracy below 1 ppm was obtained for all DART-generated ions that belonged to the test compound in the …


The Development Of Peptide Ligands To Target H69 Rrna, Danielle Nicole Dremann Jan 2016

The Development Of Peptide Ligands To Target H69 Rrna, Danielle Nicole Dremann

Wayne State University Dissertations

ABSTRACT

THE DEVELOPMENT OF PEPTIDE LIGANDS TO TARGET H69

by

DANIELLE NICOLE DREMANN

December 2015

Advisor: Prof. Christine S. Chow

Major: Chemistry (Biochemistry)

Degree: Doctor of Philosophy

In the development of peptide ligands to target H69, SPPS and ESI MS was used to determine if 1) peptides could bind to modified H69 and 2) if increased affinity for the target RNA could be enhanced with modification. An alanine and arginine scan was synthesized and tested for this determination. Selected peptides were then tested using biophysical techniques such as circular dichroism and isothermal titration calorimetry. An assay was also designed to …


Image-Charge Detection €“ Novel Instrumentation And Applications, Brandon Lee Barney Oct 2015

Image-Charge Detection €“ Novel Instrumentation And Applications, Brandon Lee Barney

Theses and Dissertations

Image-charge detection is an analytical technique in which a highly-charged particle is detected by the magnitude of the image current that it generates in a detecting electrode. This current is represented as a voltage between the charged particle and the sensing electrode. It is a single particle detection method, ideal for the analysis of large, variable mass particles such as biological cells. Some of the physical properties of Bacillus subtilis spores were explored using different applications of image-charge detection. B. subtilis is a gram-negative spore-forming bacteria that has been shown to exhibit extremophile behavior. The particular extremophile behavior that was …


Distinguishing Macrophage Activation States By Mass Spectrometry, Matthias Manfred Knust May 2015

Distinguishing Macrophage Activation States By Mass Spectrometry, Matthias Manfred Knust

Graduate Theses and Dissertations

Macrophages are versatile and highly adaptive cells that are involved in a wide range of physiological processes including host defense, homeostasis or regeneration, as well as pathogenesis. They react to their microenvironment, assuming various roles based on chemical and/or physical cues, and can reversibly shift between these so-called activation states. Concurrently, the technique of immunohistochemistry is used to gain spatial information on activated macrophages on tissue sections. The aim of this work was to find mass spectral biomarkers that allow the differentiation of activation states, and establish conditions that can be used in imaging mass spectrometry (IMS) experiments to investigate …


Investigation Into The Biological Importance And Function Of Proinsulin C-Peptide, Christina L. Newsome Jan 2015

Investigation Into The Biological Importance And Function Of Proinsulin C-Peptide, Christina L. Newsome

Theses, Dissertations and Capstones

The C-peptide of insulin was thought to be biologically inactive, but recent studies have shown that the C-peptide causes multiple molecular and physiological effects. Evidence has shown that C-peptide binds to a cell surface receptor, probably a G-protein coupled receptor, and that the COOH-terminal pentapeptide is essential for binding and constitutes an active site. For a further understanding of the detailed nature of the physiological effects of C-peptide, the receptor structure needs to be determined. We designed an affinity column using C-peptide to try and gain a better understanding of the biological effects by examining what proteins the affinity column …


Bioinformatic Solutions To Complex Problems In Mass Spectrometry Based Analysis Of Biomolecules, Ryan M. Taylor Jul 2014

Bioinformatic Solutions To Complex Problems In Mass Spectrometry Based Analysis Of Biomolecules, Ryan M. Taylor

Theses and Dissertations

Biological research has benefitted greatly from the advent of omic methods. For many biomolecules, mass spectrometry (MS) methods are most widely employed due to the sensitivity which allows low quantities of sample and the speed which allows analysis of complex samples. Improvements in instrument and sample preparation techniques create opportunities for large scale experimentation. The complexity and volume of data produced by modern MS-omic instrumentation challenges biological interpretation, while the complexity of the instrumentation, sample noise, and complexity of data analysis present difficulties in maintaining and ensuring data quality, validity, and relevance. We present a corpus of tools which improves …


Investigation Into The Cellular Actions Of Carnosine And C-Peptide, Emma H. Gardner Jan 2014

Investigation Into The Cellular Actions Of Carnosine And C-Peptide, Emma H. Gardner

Theses, Dissertations and Capstones

Carnosine is a dipeptide composed of beta-alanine and histidine found exclusively in long-lived animal tissues. The cellular action of carnosine is still under extensive investigation; however, it has been proposed to have a role as an anti-oxidant and oxygen free radical scavenger, a physiological buffer, a heavy metal chelator, and has been implicated as an anti-aging agent.2,4 Our lab has been studying the interaction between carnosine and heme by analyzing both the effect carnosine has on the glycation of the heme containing protein cytochrome c and the interaction of carnosine with free hemin. We have observed that the addition …


Monitoring Ligand-Induced Nucleic Acid Conformational Changes Using Ion Mobility Spectrometry-Mass Spectrometry, Bill Kenneth Redick Jan 2014

Monitoring Ligand-Induced Nucleic Acid Conformational Changes Using Ion Mobility Spectrometry-Mass Spectrometry, Bill Kenneth Redick

Legacy Theses & Dissertations (2009 - 2024)

Three-dimensional structures of biopolymers frequently dictate the biological role those molecules play. As such, investigation into structure of nucleic acids can provide important information pertaining to how those nucleic acids work. Many nucleic acid species, especially single-stranded RNA, fold into unique structures that allow them to function properly. Metals, and other cationic species, are often bound to the nucleic acid to make folding into the proper structure more favorable by neutralizing the negative charge on the nucleic acid imparted by the phosphate group. This investigation explores tertiary structure of nucleic acids that have been folded in the presence of ligands …


Gas-Phase Covalent And Non-Covalent Ion/Ion Chemistry Of Biological Macromolecules, John Robert Stutzman Oct 2013

Gas-Phase Covalent And Non-Covalent Ion/Ion Chemistry Of Biological Macromolecules, John Robert Stutzman

Open Access Dissertations

Gas-phase ion/ion chemistry involves the interaction of oppositely charged ions inside of the mass spectrometer. During this gas-phase chemistry, particle transfer (i.e., proton and electron) or synthesis can occur at rapid reaction rates. Particle transfer represents a mature area of ion/ion chemistry, while selective covalent modification represents a fairly new area of gas-phase chemistry. Gas-phase covalent chemistry is based on traditional solution phase organic chemistry.

The work demonstrated in this dissertation greatly involves gas-phase covalent and non-covalent Schiff base chemistry on peptide and protein ions. The reagent dianion, 4-formyl 1,3-benzene disulfonic acid, has been used to covalently modify unprotonated primary …


Bacterial Spores Remain Viable After Electrospray Charging And Desolvation, Sara Nielson Pratt Jun 2013

Bacterial Spores Remain Viable After Electrospray Charging And Desolvation, Sara Nielson Pratt

Theses and Dissertations

The electrospray survivability of B. subtilis spores and E. coli was tested in atmospheric mobility experiments. E. coli did not survive electrospray charging and desolvation, but B. subtilis did. Experimental conditions ensured that any surviving bacteria were charged, desolvated, and de-agglomerated. B. subtilis was also found to survive both positive and negative electrospray and subsequent introduction into vacuum conditions. Attempts were made to measure the charge distribution of viable B. subtilis spores using electrostatic deflection. From those experiments, it was found that either the spores do not become highly charged under the electrospray conditions used or only spores in a …


A Novel Algorithm For Validating Peptide Identification From A Shotgun Proteomics Search Engine, Ling Jian, Xinnan Niu, Zhonghang Xia, Parimal Samir, Chiranthani Sumanasekera, Zheng Mu, Jennifer L. Jennings, Kristen L. Hoek, Tara Allos, Leigh M. Howard, Kathryn M. Edwards, P. Anthony Weil, Andrew J. Link Feb 2013

A Novel Algorithm For Validating Peptide Identification From A Shotgun Proteomics Search Engine, Ling Jian, Xinnan Niu, Zhonghang Xia, Parimal Samir, Chiranthani Sumanasekera, Zheng Mu, Jennifer L. Jennings, Kristen L. Hoek, Tara Allos, Leigh M. Howard, Kathryn M. Edwards, P. Anthony Weil, Andrew J. Link

Chemistry Faculty Research

Liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) has revolutionized the proteomics analysis of complexes, cells, and tissues. In a typical proteomic analysis, the tandem mass spectra from a LC–MS/MS experiment are assigned to a peptide by a search engine that compares the experimental MS/MS peptide data to theoretical peptide sequences in a protein database. The peptide spectra matches are then used to infer a list of identified proteins in the original sample. However, the search engines often fail to distinguish between correct and incorrect peptides assignments. In this study, we designed and implemented a novel algorithm called De-Noise to …


Mass Spectrometry-Based Methods For The Detection And Characterization Of Protein-Tyrosine Nitration, Kent W. Seeley Jan 2013

Mass Spectrometry-Based Methods For The Detection And Characterization Of Protein-Tyrosine Nitration, Kent W. Seeley

USF Tampa Graduate Theses and Dissertations

Protein tyrosine nitration (PTN) is a posttranslational modification resulting from oxidative/nitrosative stress that has been implicated in a wide variety of disease states. Characterization of PTN is challenging due to several factors including its low abundance in a given proteome, preferential site modification, multiple target site proximity within unique peptide sequences, and analytical method and instrument limitations. Current analytical techniques are insufficiently sensitive to identify endogenous nitration sites without incorporation of either nitrotyrosine or target protein enrichment. However, enrichment proficiency can also be inadequate. Chemical derivatization of the nitro- moiety can be incomplete or result in undesirable byproduct formation, while …


Novel Ion Trap Made Using Lithographically Patterned Plates, Ying Peng Jul 2011

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, …


Method Development And Applications To Screening And Characterization Of Rrna-Targeting Small Molecules, Papa Nii Asare-Okai Jan 2011

Method Development And Applications To Screening And Characterization Of Rrna-Targeting Small Molecules, Papa Nii Asare-Okai

Wayne State University Dissertations

A series of single ring aminoglycoside analogues was tested for binding to a model RNA representing the A site using electrospray ionization mass spectrometry (ESI-MS). Several of the synthetic analogues with low molecular weights were found to bind to the RNA with affinities comparable to the parental aminoglycoside neamine, with apparent dissociation constants in the low micromolar range. Salt dependence of the affinity constants for the single ring analogues revealed a predominantly electrostatic binding mode. Footprinting experiments revealed that one of the compounds (DHR23) has a similar binding site as the antibiotic paromomycin. DMS chemical probing results also suggest that …


Targeted Identification Of Metastasis-Associated Cell-Surface Sialoglycoproteins In Prostate Cancer, Lifang Yang, Julius O. Nyalwidhe, Sigi Guo, Richard R. Drake, O. John Semmes Jan 2011

Targeted Identification Of Metastasis-Associated Cell-Surface Sialoglycoproteins In Prostate Cancer, Lifang Yang, Julius O. Nyalwidhe, Sigi Guo, Richard R. Drake, O. John Semmes

Bioelectrics Publications

Covalent attachment of carbohydrates to proteins is one of the most common post-translational modifications. At the cell surface, sugar moieties of glycoproteins contribute to molecular recognition events involved in cancer metastasis. We have combined glycan metabolic labeling with mass spectrometry analysis to identify and characterize metastasis-associated cell surface sialoglycoproteins. Our model system used syngeneic prostate cancer cell lines derived from PC3 (N2, nonmetastatic, and ML2, highly metastatic). The metabolic incorporation of AC4ManNAz and subsequent specific labeling of cell surface sialylation was confirmed by flow cytometry and confocal microscopy. Affinity isolation of the modified sialic-acid containing cell surface proteins …