DOCSLIB.ORG

Hybrid Mass Spectrometers for Tandem Mass Spectrometry

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

FOCUS: COOKS, 2006 DISTINGUISHED CONTRIBUTION IN MASS SPECTROMETRY AWARDEE ACCOUNT AND PERSPECTIVE Hybrid Mass Spectrometers for Tandem Mass Spectrometry Gary L. Glisha and David J. Burinskyb a Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina, USA b GlaxoSmithKline, Five Moore Drive, P.O. Box 13398, Research Triangle Park, North Carolina, USA Mass spectrometers that use different types of analyzers for the first and second stages of mass analysis in tandem mass spectrometry (MS/MS) experiments are often referred toas “hybrid” mass spectrometers. The general goal in the design of a hybrid instrument is to combine different performance characteristics offered by various types of analyzers into one mass spectrometer. These performance characteristics may include mass resolving power, the ion kinetic energy for collision-induced dissociation, and speed of analysis. This paper provides a review of the development of hybrid instruments over the last 30 years for analytical applications. (J Am Soc Mass Spectrom 2008, 19, 161–172) © 2008 American Society for Mass Spectrometry andem mass spectrometry (MS/MS), in a very “high” ion kinetic energies (5–20 keV), whereas “low” generic description, is a process in which an ion ion kinetic energies (Ͻ50 eV) are typical in quadrupole Tformed in anion source is mass-selected in the mass filters and ion traps. The ion kinetic energy is an firststage of analysis, reacted, and thenthe charged important parameter in MS/MS experiments because products from the reaction are analyzed in the second the most common reaction involves colliding the ion of stage of analysis. The type and quality of data that is interest with a target gas atom or molecule. When obtained can vary greatly depending upon the type of performing ion-neutral collision experiments, the pos- analyzer used in the first and second stages of analysis, sible reactions that can be accessed (e.g., collision- and the type ofreaction performed betweenthe stages induced dissociation, collisional cooling, charge permu- of analysis. The reactions that can be done also can tation, ion/molecule reaction) depends upon the ion depend upon the type of analyzer. Over the years there kinetic energy.The appearance of the MS/MS spectrum have been a variety of means developed to measure the can change drastically as a function of the collision (ion mass-to-charge ratio of gas-phase ions.The most com- kinetic) energy. A related factor that is equally impor- mon methods involve: dispersion based on ion momen- tant, but often not considered, is the time frame of the tum or kinetic energy (magnetic and electric sector experiment, that is, the elapsed time between the colli- instruments); separation in time based onion velocity sion event and the second (or next) stage of analysis. (time-of-flight); transmissionthrough an electrody- With high kinetic energies, the experimental time frame namic field (quadrupole mass filter); and periodic mo- is typicallyquite short (i.e., microseconds). Short disso- tion in a magnetic or electrodynamic field (ion traps). ciation times mean a greater kinetic shift. A large kinetic There are differences in the experimental parameters shift typically favors dissociations that occur faster, but associated with these various analysis methods that are that also require more internal energy to dissociate fast pertinent to the MS/MS experiment. Some parameters enough to be observed on the time scale of the experi- are obvious, typically related to the performance of the ment. Not only does this lead to differences in the mass analyzer while others are more subtle, related to appearance of high-energy and low-energy MS/MS the reactions/chemistry occurring between the stages spectra, but also to reduced MS/MS efficiency for of analysis. Many times these different parameters are higher kinetic energy CID. used to categorize MS/MS experiments. Another distinguishing feature by which tandem mass One parameter is the ion kinetic energy. Sector and spectrometry experiments can be classified or categorized time-of-flight (TOF) instruments typically operate at is whether the analysis and excitation events are separated spatially or temporally. Techniques in which the ions are separated “in space”—sector, TOF analyzers, and quad- Address reprint requests to Dr. G. L. Glish, Department of Chemistry, University of North Carolina-Chapel Hill, CB# 3290, Chapel Hill, NC rupole mass filters—are commonly referred to as “beam” 27599-3290, USA. E-mail: [email protected] techniques because ions traverse the analyzer as a contin- Published online January 9, 2008 © 2008 American Society for Mass Spectrometry. Published by Elsevier Inc. Received October 17, 2007 1044-0305/08/$32.00 Revised November 7, 2007 doi:10.1016/j.jasms.2007.11.013 Accepted November 8, 2007 162 GLISH AND BURINSKY J Am Soc Mass Spectrom 2008, 19, 161–172 Table 1. Comparison of mass analyzers with respect to key performance attributes Resolving power Mass accuracy Analyzer type Kinetic energy MS-1 MS-2 MS-1 MS-2 Measurement timea (seconds) Magnetic (B) sector High Medium Medium ppt ppt 10Ϫ5 Electric (E) sector Highnab Low nab ppt10Ϫ5 Electric and magnetic sectorc High High Medium ppm ppt 10Ϫ5 Time-of-flight (TOF) High Low Mediumd ppm ppm10Ϫ5 Quadrupole mass filter (Q) Low Low Low ppt ppt10Ϫ4 Quadrupole ion trap(QIT) Low Low Low ppt ppt10Ϫ2 FTICR Low High High ppm ppm 10Ϫ1 Orbitrap High nab High nab ppm 10Ϫ1 aThe time, after activation, for the ions to react prior to the second stage of analysis. bna: not applicable; this analyzer has not been used for the first stageofanMS/MS experiment. There is currently no mode of operation in which a parent ion can be mass selected for a subsequent stage of analysis. cWhen electric and magnetic sectors are used as a double focusing mass spectrometer for one stage of analysis, either prior to (MS-1) the reaction, or subsequent to (MS-2) the reaction. dThe resolving power is medium if the TOF ion axis is orthogonal to the first stage of MS; if the axes are coaxial, the resolving power is low. uous or pulsed beam (analogous to a laser beam). For the of an MS/MS experiment is no different than that beam techniques, every stage of mass-to-charge analysis is measured for a normal mass spectrum when using that done in a separate analyzer, such that the two (or more) analyzer. However, that is not necessarily true for the stages of analysis are separated (physically) in space. resolving power in the second stageof mass analysis. Conversely, trapping instruments such as quadrupole ion For example, because of the kinetic energy release traps, Fourier transform ion cyclotron resonance (FTICR) associated with dissociation of an ion, a single magnetic spectrometers, and orbitraps, characterize ions based sector or electric sector exhibits low mass resolving upon the frequency of their motion in a defined space. In power if CID occurs at high kinetic energies. Con- theMS/MS experiment using quadrupole ion traps and versely, if a double focusing electric/magnetic sector FTICR spectrometers, all stages of the experiment can combination is used medium resolving power is ob- performed in the same analyzer, with the different stages served. Table 1 summarizes the performance parame- being separated in time rather than spatially. The overall ters for the various analyzers. experimental efficiency is almost alwayshigher because 1) Hybrid MS/MS instruments use various combina- the ions do not have to be transferred from one analyzer to tions of these analyzers to obtain desirable performance another, and 2) there is typically a much longer time characteristics for the phenomena being investigated. period for reaction and dissociation, so the kinetic shift is Typically, resolving power and measurement accuracy small. However, the overall experiment can take signifi- in each stage of the mass spectral analysis are of cantly more time to complete compared withbeam-type primary importance. However, the kinetic energy used instruments. for CID can also be a critical parameter, depending on The last two attributes that can be used to classify the the information being sought. Additionally, the speed various mass analysis techniques are resolving power of analysis (duty cycle) can also be an important param- Ϫ [(m/z)(⌬m/z) 1] and measurement accuracy. Mass mea- eter. The development of many early hybrid instru- surement accuracy is either “high”, expressed in parts ments was motivated by the desire for fast MS/MS per million (ppm),or“low,” expressed in parts per spectral acquisition times required by the time scale of thousand (ppt). FTICR spectrometers, orbitrapsand a chromatographic separation. The early hybrid instru- TOF analyzers can routinely achieve low- or sub-ppm ments (1980s) all usedbeam type analyzers (beam-beam mass accuracies, while the other analyzers (i.e., quad- instruments) because these were the standards of the rupole mass filters or ion traps) are typically in the ppt day, with trapping instruments just being introduced as range. In terms of mass resolving power, analyzers of commercially viable mass analyzers. Two of these various types are capable of either low, medium, or beam-beam type hybrid instruments evolved into com- high resolving power. Clearly, relative terminology mercial instruments, sector/Q and Q/TOF, with the such as low, medium, andhigh can be debated.That latter one still being a popular instrument today. Sub- being said, for the purpose of this discussion, the sequently (1990s), beam-trap type instruments were following definitions apply to those terms: “low”, less explored, followed by trap-beam instruments. A hand- than 1000; “medium”, 1000 to 10,000; “high”, greater ful of beam-trap instruments (sector/QIT) have been than 10,000. It should also be noted that whilethe terms commercialized. The trap-beam instrument closely re- “resolving power” and “resolution” are often used lated to the Q/TOF, the QIT/TOF, has become commer- interchangeably in the mass spectrometry literature, cially available.
Recommended publications
  • About Magnetic Sector Mass Spec- Trometers

    About Magnetic Sector Mass Spec- Trometers

    About Magnetic Sector Mass Spec- trometers Double-focusing magnetic sector mass spectrometers provide high sensitivity, high resolution, and a reproducibility that is unmatched in any other kind of mass analyzer. A double-focusing magnetic sector mass spectrometer has at least four components: . An ion source in which ions are formed and accelerated to energies of up to as high as 10 kilovolts. A magnetic sector with a magnetic field that exerts a force perpendicular to the ion mo- tion to deflect ions according to their momentum. An electric sector with an electric field that exerts a force perpendicular to the ion mo- tion to deflect ions according to their kinetic energy. A detector that produces a response that is proportional to the number of ions. Slits are placed in the ion path to define the positions and energies of the ions that strike the detector. In general, decreasing the slit widths increases the mass resolution but re- duces the number of ions that are detected. Additional electrostatic lenses are com- monly used to shape and deflect the ion beam to optimize peak shape and maximize ion beam transmission from the source to the detector. JEOL uses octapole and quadrupole focusing lenses to simplify the ion optical design. Collision chambers in the first field-free region (just after the ion source) and second field-free region (just after the magnet and before the electric sector) are used to induce ions to fragment in collision-induced-dissociation experiments (MS/MS). The term "double-focusing" refers to the fact that the combination of electric and mag- netic sectors focuses ions according to both direction and energy to provide higher reso- lution than can be obtained with a single magnetic sector.
  • Tandem Mass Spectrometry (MS–MS)

    Tandem Mass Spectrometry (MS–MS)

    Advanced Analytical Chemistry Lecture 22 Chem 4631 Tandem Mass Spectrometry (MS–MS) Tandem mass spectrometry (MS–MS) is a term which covers a number of techniques where one stage of mass spectrometry (not necessarily the first) is used to isolate an ion of interest and a second stage is then used to probe the relationship of this ion with others from which it may have been generated or which it may generate on decomposition. Chem 5570 Tandem Mass Spectrometry (MS–MS) Chem 5570 The two analyzers (MS-MS) can be separated by a collision cell (can be another MS) into which an inert gas (e.g. argon, xenon) is admitted to collide with the selected sample ions and bring about their fragmentation. Tandem MS have the ability to perform multiple steps on a single sample. The MS selects a specific ion, fragment the ion, and generate another mass spec – able to repeat the cycle several times. Chem 5570 The analyzers can be of the same or of different types, the most common combinations being: quadrupole - quadrupole magnetic sector - quadrupole magnetic sector - magnetic sector quadrupole - time-of-flight Fragmentation experiments can also be performed on certain single analyzer mass spectrometers such as ion trap and time-of-flight instruments, the latter type using a post-source decay experiment to effect the fragmentation of sample ions. Chem 5570 Tandem Mass Spectrometry (MS–MS) TIC - Total ion current or total ion chromatogram The TIC represents the sum of all signal intensities of a single scan spectrum. The TIC is usually calculated by the data system of the mass spectrometer and plotted against time or scan number to give a measure for evaporation/ionization of a sample over the duration of the whole measurement.
  • Front-End Methods for Enhancing the Analytical Power of Mass Spectrometry

    Front-End Methods for Enhancing the Analytical Power of Mass Spectrometry

    FRONT-END METHODS FOR ENHANCING THE ANALYTICAL POWER OF MASS SPECTROMETRY PETER PAUL LIUNI A DISSERTAITON SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FUFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY GRADUATE PROGRAM IN CHEMISTRY YORK UNIVERSITY TORONTO, ONTARIO December 2015 © Peter Paul Liuni, 2015 Abstract The analytical power and versatility of mass spectrometry can be enhanced by adding ‘front-end’ devices, which provide additional functionality before, during or immediately after ElectroSpray Ionization (ESI). Such devices can include Ion mobility spectrometry (IMS) and Time-Resolved ElectroSpray Ionization (TRESI) which provide enhanced analysis of illicit compounds, protein folding, enzyme kinetics, and catalysis-linked dynamics. With respect to IMS, this work describes implementation of a hybrid Trace Compound Detector (TCD) system that combines IMS and MS to allow for rapid front- end mobility separation, followed by characterization and identification of analytical markers of seized opium by mass spectrometry. Ultimately, this device provides an avenue for rapid prosecution based on simultaneous detection and unambiguous identification of illicit drugs. TRESI is used to extend Mass Spectrometry (MS) to millisecond-timescale reaction studies. In the first instance, we combine TRESI with Travelling Wave Ion Mobility Spectrometry (TWIMS) to compare equilibrium and kinetic unfolding intermediates of cytochrome c, showing a high degree of correlation between all species populated under these substantially different regimes. We then combine TRESI with Hydrogen Deuterium Exchange (TRESI-HDX) to elucidate the relationship between structural fluctuations (conformational dynamics) of enzymes and their catalytic activity. The results of this work include a new model for catalysis-linked dynamics, in which the nature of the conformational landscape explored by an enzyme is independent of catalysis, but the rate at which the landscape is explored is enhanced for catalytically active species.
  • Novel Quadrupole Time-Of-Flight Mass Spectrometry for Shotgun Proteomics

    Novel Quadrupole Time-Of-Flight Mass Spectrometry for Shotgun Proteomics

    DISSERTATION ZUR ERLANGUNG DES DOKTORGRADES DER FAKULTÄT FÜR CHEMIE UND PHARMAZIE DER LUDWIG-MAXIMILIANS-UNIVERSITÄT MÜNCHEN Novel quadrupole time-of-flight mass spectrometry for shotgun proteomics von Scarlet Svenja Anna-Maria Beck aus Tettnang 2016 ii Erklärung Diese Dissertation wurde im Sinne von §7 der Promotionsordnung vom 28. November 2011 von Herrn Prof. Dr. Matthias Mann betreut. Eidesstattliche Versicherung Diese Dissertation wurde eigenständig und ohne unerlaubte Hilfe erarbeitet. München, den 25.04.2017 …………………………………………………………………………………………Scarlet Beck Dissertation eingereicht am 23.09.2016 1. Gutachter: Prof. Dr. Matthias Mann 2. Gutachter: Prof. Dr. Jürgen Cox Mündliche Prüfung am 04.11.2016 iii iv ABSTRACT Mass spectrometry (MS)-based proteomics has become a powerful technology for the identification and quantification of thousands of proteins. However, the coverage of complete proteomes is still very challenging due to the high sample complexity and the difference in protein concentrations. In data-dependent shotgun proteomics several peptides elute simultaneously from the column and are isolated by the quadrupole and fragmented by the collision cell one at a time. This method has two major disadvantages. On the one hand, a large number of eluting peptides cannot be targeted since the sequencing speeds of current instruments are too slow and on the other hand, peptides that only differ slightly in mass and elute together are co-isolated and co-fragmented, resulting in chimeric MS2 spectra. Therefore an urgent need for further developments and improvements of mass spectrometers remains. The aim of this thesis was to co-develop, evaluate and improve novel quadrupole time-of-flight (QTOF) mass spectrometers. In my first project I have described the developments and improvements of the hardware of the high-resolution QTOF mass spectrometer, the impact II, and have shown that this instrument can be used for very deep coverage of diverse proteomes as well as for accurate and reproducible quantification.
  • An Introduction to Mass Spectrometry

    An Introduction to Mass Spectrometry

    An Introduction to Mass Spectrometry by Scott E. Van Bramer Widener University Department of Chemistry One University Place Chester, PA 19013 [email protected] http://science.widener.edu/~svanbram revised: September 2, 1998 © Copyright 1997 TABLE OF CONTENTS INTRODUCTION ........................................................... 4 SAMPLE INTRODUCTION ....................................................5 Direct Vapor Inlet .......................................................5 Gas Chromatography.....................................................5 Liquid Chromatography...................................................6 Direct Insertion Probe ....................................................6 Direct Ionization of Sample ................................................6 IONIZATION TECHNIQUES...................................................6 Electron Ionization .......................................................7 Chemical Ionization ..................................................... 9 Fast Atom Bombardment and Secondary Ion Mass Spectrometry .................10 Atmospheric Pressure Ionization and Electrospray Ionization ....................11 Matrix Assisted Laser Desorption/Ionization ................................ 13 Other Ionization Methods ................................................13 Self-Test #1 ...........................................................14 MASS ANALYZERS .........................................................14 Quadrupole ............................................................15
  • Peptide and Protein Quantification Using Itraq with Electron Transfer Dissociation

    Peptide and Protein Quantification Using Itraq with Electron Transfer Dissociation

    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Peptide and Protein Quantification Using iTRAQ with Electron Transfer Dissociation Doug Phanstiel,a Yi Zhang,c Jarrod A. Marto,c,d and Joshua J. a,bCoon a Department of Chemistry, University of Wisconsin, Madison, Wisconsin, USA b Department of Biomolecular Chemistry, University of Wisconsin, Madison, Wisconsin, USA c Department of Cancer Biology and Blais Proteomics Center, Dana-Farber Cancer Institute, Boston, Massachusetts, USA d Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA Electron transfer dissociation (ETD) has become increasingly used in proteomic analyses due to its complementarity to collision-activated dissociation (CAD) and its ability to sequence peptides with post-translation modifications (PTMs). It was previously unknown, however, whether ETD would be compatible with a commonly employed quantification technique, isobaric tags for relative and absolute quantification (iTRAQ), since the fragmentation mechanisms and pathways of ETD differ significantly from CAD. We demonstrate here that ETD of iTRAQ labeled peptides producesc- and z˙ -type fragment ions as well as reporter ions that are unique from those produced by CAD. Exact molecular formulas of product ions were determined by ETD fragmentation of iTRAQ-labeled synthetic peptides followed by high mass accuracy orbitrap mass analysis. These experiments revealed that ETD cleavage␣ of the N–C bond of the iTRAQ tag results in fragment ions that could be used for quantification. Synthetic peptide work demonstrates that these fragment ions provide up to three channels of quantification and that the quality is similar to that provided by beam-type CAD.
  • Dynamic Range of Mass Accuracy in LTQ Orbitrap Hybrid Mass Spectrometer

    Dynamic Range of Mass Accuracy in LTQ Orbitrap Hybrid Mass Spectrometer

    Dynamic Range of Mass Accuracy in LTQ Orbitrap Hybrid Mass Spectrometer Alexander Makarov, Eduard Denisov, Oliver Lange, and Stevan Horning Thermo Electron (Bremen) GmbH, Bremen, Germany Using a novel orbitrap mass spectrometer, the authors investigate the dynamic range over which accurate masses can be determined (extent of mass accuracy) for short duration experiments typical for LC/MS. A linear ion trap is used to selectively fill an intermediate ion storage device (C-trap) with ions of interest, following which the ensemble of ions is injected into an orbitrap mass analyzer and analyzed using image current detection and fast Fourier transformation. Using this technique, it is possible to generate ion populations with intraspec- trum intensity ranges up to 104. All measurements (including ion accumulation and image current detection) were performed in less than1sataresolving power of 30,000. It was shown that 5-ppm mass accuracy of the orbitrap mass analyzer is reached with Ͼ95% probability at a dynamic range of more than 5000, which is at least an order of magnitude higher than typical values for time-of-flight instruments. Due to the high resolving power of the orbitrap, accurate mass of an ion could be determined when the signal was reliably distinguished from noise Ͼ ѧ (S/Np-p 2 3). (J Am Soc Mass Spectrom 2006, 17, 977–982) © 2006 American Society for Mass Spectrometry he dynamic range over which accurate measure- troiding introduced by the noise of the image current ments of mass can be made (“extent of mass preamplifier[5–8].UnlikeTOFs,FTICRemploysmuch Taccuracy”) is a key analytical figure-of-merit for slower acquisition systems with much higher dynamic any accurate-mass analyzer.
  • Implementation of Electron-Transfer Dissociation on a Hybrid Linear Ion Trap-Orbitrap Mass Spectrometer

    Implementation of Electron-Transfer Dissociation on a Hybrid Linear Ion Trap-Orbitrap Mass Spectrometer

    Anal. Chem. 2007, 79, 3525-3534 Accelerated Articles Implementation of Electron-Transfer Dissociation on a Hybrid Linear Ion Trap-Orbitrap Mass Spectrometer Graeme C. McAlister,† Doug Phanstiel,† David M. Good,† W. Travis Berggren,‡ and Joshua J. Coon*,†,§ Departments of Chemistry and Biomolecular Chemistry, University of Wisconsin, Madison, Wisconsin 53706, and WiCell Research Institute, Madison, Wisconsin 53706 We describe the adaptation of a hybrid quadrupole linear electron-transfer dissociation (ETD) has generated considerable ion trap-orbitrap mass spectrometer to accommodate interest in the field of proteomic research.1-3 The utility of the electron-transfer ion/ion reactions (ETD) for peptide and technique to localize post-translational modifications (PTMs), its protein characterization. The method utilizes pulsed, dual relative indifference to amino acid composition or order, and electrospray ion sources and requires minimal instrument capacity to randomly dissociate large peptide and even whole modification. Switching between cation and reagent anion protein cations on a chromatographic time scale make it the injection schemes is automated and accomplished within perfect complement to conventional collision-activated methodol- a few hundred milliseconds. Ion/ion reactions are con- ogy (CAD).4-8 Still, because they are generated within the context ducted within the linear ion trap, after which the c- and of a radio frequency (rf) ion trap, ETD-type product ions are almost z-type product ions are passed to the orbitrap for high- exclusively mass analyzed with low m/z resolution and accuracy resolution m/z analysis. With this arrangement, mass (i.e., that typically achieved with ion trap devices). Doubtless ion accuracies are typically measured to within 2 ppm at a trap MS systems offer a splendid format for conducting ion/ion resolving power of 60 000.
  • Compositional Analysis of Complex Organic Mixtures by Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Zhigang Wu

    Compositional Analysis of Complex Organic Mixtures by Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Zhigang Wu

    Florida State University Libraries Electronic Theses, Treatises and Dissertations The Graduate School 2004 Compositional Analysis of Complex Organic Mixtures by Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry Zhigang Wu Follow this and additional works at the FSU Digital Library. For more information, please contact [email protected] THE FLORIDA STATE UNIVERSITY COLLEGE OF ARTS AND SCIENCES Compositional Analysis of Complex Organic Mixtures by Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry By Zhigang Wu A Dissertation submitted to the Department of Chemistry and Biochemistry in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Degree Awarded: Spring Semester, 2004 Copyright2004 Zhigang Wu All Rights Reserved The members of the Committee approve the Dissertation of Zhigang Wu Defended on April 7, 2004. Alan G. Marshall Professor Directing Dissertation William M. Landing Outside Committee Member William T. Cooper Committee Member Timothy A. Cross Committee Member Ryan P. Rodgers Committee Member The Office of Graduate Studies has verified and approved the above named committee members. ii To my parents, Xiaohua Wu and Shiping Cao; iii ACKNOWLEDGMENTS First, I need to thank Dr. Alan G. Marshall, my academic graduate advisor and supporter. His deep and broad academic knowledge and great personality are invaluable throughout my graduate career. His wise and forecasting advices has helped me directly cut to the “point” and inspired me to discover more underneath. I also wish to acknowledge Dr. Ryan P. Rodgers, my supervisor, for his expertise, direction, and support. His initiation and development in petroleum applications have led me to a broader and better understanding of this area.
  • Utilizing a Hybrid Mass Spectrometer to Enable Fundamental Protein Characterization: Intact Mass Analysis and Top-Down Fragmentation with the LTQ Orbitrap MS

    Utilizing a Hybrid Mass Spectrometer to Enable Fundamental Protein Characterization: Intact Mass Analysis and Top-Down Fragmentation with the LTQ Orbitrap MS

    Application Note: 498 Utilizing a Hybrid Mass Spectrometer to Enable Fundamental Protein Characterization: Intact Mass Analysis and Top-Down Fragmentation with the LTQ Orbitrap MS Tonya Pekar Second, Vlad Zabrouskov, Thermo Fisher Scientific, San Jose, CA, USA Alexander Makarov, Thermo Fisher Scientific, Bremen, Germany Introduction Experimental Key Words A fundamental stage in protein characterization is to Protein standards, including bovine carbonic anhydrase, • LTQ Orbitrap Velos determine and verify the intact state of the macromolecule. yeast enolase, bovine transferrin and human monoclonal This is often accomplished through the use of mass IgG, were purchased from Sigma-Aldrich. For direct • LTQ Orbitrap XL spectrometry (MS) to first detect and measure the molecular infusion, proteins in solution were purified by either a • Applied mass. Beyond confirmation of intact mass, the next objective Thermo Scientific Vivaspin centrifugal spin column or a Fragmentation is the verification of its primary structure, the amino acid size-exclusion column (GE Healthcare), employing at least Techniques sequence of the protein. Traditionally, a map of the two rounds of buffer exchange into 10 mM ammonium macromolecule is reconstructed from matching masses of acetate. Protein solutions were at a concentration of least • Electron Transfer peptide fragments produced through external enzymatic 1 mg/mL prior to clean-up. Samples were diluted into Dissociation ETD digestion of the protein to masses calculated from an in 50:50:0.1 acetonitrile:water:formic acid prior to infusion silico • Top-Down digest of the target protein sequence. A more direct into the mass spectrometer. Instrument parameters were approach involves top-down MS/MS of the intact protein altered during infusion of protein solutions to optimize the Proteomics molecular ion.
  • Orbitrap Elite Hybrid MS Provides the Ultimate Level of Versatility and Performance for Your Research

    Orbitrap Elite Hybrid MS Provides the Ultimate Level of Versatility and Performance for Your Research

    mass spectrometry Product Specifications Combining the next generation Thermo Scientific Velos Pro ion trap with the new high-field Orbitrap technology, the Thermo Scientific Orbitrap Elite hybrid MS provides the ultimate level of versatility and performance for your research. Thermo Scientific Orbitrap Elite High-Field Orbitrap Hybrid Mass Spectrometer • Novel high-field Orbitrap analyzer The ultrahigh resolution provides • Resolving power > 240,000 FWHM certainty in analytical results by enabling • Advanced signal processing molecular weight determination for intact • Multiple fragmentation techniques: CID, proteins and in-depth analysis of isobaric HCD and optionally ETD species. The unsurpassed resolution of the • Parallel MS and MSn analysis system is especially useful when dealing • Velos Pro ion trap generation II ion optics with complex and low abundance samples, with neutral blocking technology increase in applications such as proteomics, metabo- robustness lomics and lipidomics. The Orbitrap Elite hybrid MS can The Thermo Scientific Orbitrap Elite MS is perform a wide variety of experiments from the industry-leading high performance in-depth discovery based experiments to hybrid mass spectrometer combining the comprehensive qual/quan experiments. The novel high-field Orbitrap™ analyzer with availability of multiple fragmentation tech- the latest dual-pressure linear ion trap, the niques (CID, HCD and optional ETD) offers Thermo Scientific Velos Pro. a new level of versatility and performance The high-field Orbitrap analyzer
  • 82756031.Pdf

    82756031.Pdf

    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Do Charge-Remote Fragmentations Occur under Matrix-Assisted Laser Desorption Ionization Post-Source Decompositions and Matrix-Assisted Laser Desorption Ionization Collisionally Activated Decompositions? M. Rosario M. Domingues, M. Grac¸a O. S.-Marques, Carla A. M. Vale, M. Grac¸a Neves, J. A. S. Cavaleiro, and A. J. Ferrer-Correia Department of Chemistry, University of Aveiro, Aveiro, Portugal Olga V. Nemirovskiy and Michael L. Gross Department of Chemistry, Washington University, St Louis, Missouri, USA The precursor ions of tetraphenylporphyrins that are substituted with fatty acids can be introduced into the gas phase by matrix-assisted laser desorption ionization (MALDI) and undergo post-source and collisionally activated decompositions (CAD) in a time-of-flight mass spectrometer. The goal of the research is to obtain a better understanding of post-source decompositions (PSD); specifically, we asked the question of whether ions undergoing PSD have sufficient energy to give charge-remote fragmentations along an alkyl chain. We chose the porphyrin macrocycle because we expected it to act as an inert “support,” allowing the molecule to be desorbed by MALDI and to be amenable to charge-remote fragmentation. MALDI-PSD and MALDI-CAD spectra are similar to high-energy CAD spectra and consid- erably more informative than low-energy CAD spectra, showing that charge-remote fragmen- tations of the fatty acid moieties do occur upon MALDI-PSD and MALDI-CAD. (J Am Soc Mass Spectrom 1999, 10, 217–223) © 1999 American Society for Mass Spectrometry ost-source decompositions (PSD) of ions pro- ever, observed different fragmentation pathways in duced by matrix-assisted laser desorption (MALDI) MALDI-PSD spectra when compared with those ob- Phas become a valuable structural tool for peptides served in LE-CAD and HE-CAD spectra.