1
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Kontodimas V, Yaman M, Greis K, Lettow M, Pagel K, Marianski M. Reinvestigation of the internal glycan rearrangement of Lewis a and blood group type H1 epitopes. Phys Chem Chem Phys 2024; 26:14160-14170. [PMID: 38712976 PMCID: PMC11147448 DOI: 10.1039/d3cp04491b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Protonated ions of fucose-containing oligosaccharides are prone to undergo internal glycan rearrangement which results in chimeric fragments that obfuscate mass-spectrometric analysis. Lack of accessible tools that would facilitate systematic analysis of glycans in the gas phase limits our understanding of this phenomenon. In this work, we use density functional theory modeling to interpret cryogenic IR spectra of Lewis a and blood group type H1 trisaccharides and to establish whether these trisaccharides undergo the rearrangement during gas-phase analysis. Structurally unconstrained search reveals that none of the parent ions constitute a thermodynamic global minimum. In contrast, predicted collision cross sections and anharmonic IR spectra provide a good match to available experimental data which allowed us to conclude that fucose migration does not occur in these antigens. By comparing the predicted structures with those obtained for Lewis x and blood group type H2 epitopes, we demonstrate that the availability of the mobile proton and a large difference in the relative stability of the parent ions and rearrangement products constitute the prerequisites for the rearrangement reaction.
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Affiliation(s)
- Vasilis Kontodimas
- Department of Chemistry, Hunter College, The City University of New York, New York, NY 10065, USA.
| | - Murat Yaman
- Department of Chemistry, Hunter College, The City University of New York, New York, NY 10065, USA.
- Ph.D. Programs in Chemistry and Biochemistry, The Graduate Center, The City University of New York, New York, NY 10016, USA
| | - Kim Greis
- Fritz-Haber-Intitut der Max Planck Gesellschaft, 14195 Berlin, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
- Laboratory of Organic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Maike Lettow
- Fritz-Haber-Intitut der Max Planck Gesellschaft, 14195 Berlin, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Kevin Pagel
- Fritz-Haber-Intitut der Max Planck Gesellschaft, 14195 Berlin, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Mateusz Marianski
- Department of Chemistry, Hunter College, The City University of New York, New York, NY 10065, USA.
- Ph.D. Programs in Chemistry and Biochemistry, The Graduate Center, The City University of New York, New York, NY 10016, USA
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2
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Lettow M, Greis K, Mucha E, Lambeth TR, Yaman M, Kontodimas V, Manz C, Hoffmann W, Meijer G, Julian RR, von Helden G, Marianski M, Pagel K. Decoding the Fucose Migration Product during Mass-Spectrometric analysis of Blood Group Epitopes. Angew Chem Int Ed Engl 2023; 62:e202302883. [PMID: 36939315 PMCID: PMC10299593 DOI: 10.1002/anie.202302883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 03/21/2023]
Abstract
Fucose is a signaling carbohydrate that is attached at the end of glycan processing. It is involved in a range of processes, such as the selectin-dependent leukocyte adhesion or pathogen-receptor interactions. Mass-spectrometric techniques, which are commonly used to determine the structure of glycans, frequently show fucose-containing chimeric fragments that obfuscate the analysis. The rearrangement leading to these fragments-often referred to as fucose migration-has been known for more than 25 years, but the chemical identity of the rearrangement product remains unclear. In this work, we combine ion-mobility spectrometry, radical-directed dissociation mass spectrometry, cryogenic IR spectroscopy of ions, and density-functional theory calculations to deduce the product of the rearrangement in the model trisaccharides Lewis x and blood group H2. The structural search yields the fucose moiety attached to the galactose with an α(1→6) glycosidic bond as the most likely product.
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Affiliation(s)
- Maike Lettow
- Fritz-Haber-Intitut der Max-Planck-Gesellschaft, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Germany
| | - Kim Greis
- Fritz-Haber-Intitut der Max-Planck-Gesellschaft, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Germany
| | - Eike Mucha
- Fritz-Haber-Intitut der Max-Planck-Gesellschaft, Germany
| | - Tyler R Lambeth
- Department of Chemistry, University of California, Riverside, USA
| | - Murat Yaman
- Department of Chemistry and Biochemistry, Hunter College, The City University of New York, USA
- The PhD Program in Chemistry and Biochemistry, The Graduate Center, The City University of New York, USA
| | - Vasilis Kontodimas
- Department of Chemistry and Biochemistry, Hunter College, The City University of New York, USA
| | - Christian Manz
- Fritz-Haber-Intitut der Max-Planck-Gesellschaft, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Germany
| | - Waldemar Hoffmann
- Fritz-Haber-Intitut der Max-Planck-Gesellschaft, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Germany
| | - Gerard Meijer
- Fritz-Haber-Intitut der Max-Planck-Gesellschaft, Germany
| | - Ryan R Julian
- Department of Chemistry, University of California, Riverside, USA
| | | | - Mateusz Marianski
- Department of Chemistry and Biochemistry, Hunter College, The City University of New York, USA
- The PhD Program in Chemistry and Biochemistry, The Graduate Center, The City University of New York, USA
| | - Kevin Pagel
- Fritz-Haber-Intitut der Max-Planck-Gesellschaft, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Germany
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3
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Tolpina MD, Vasileva ID, Samgina TY. Modern Approaches in de novo Sequencing of Nontryptic Peptides of Ranid and Hylid Frogs by Means of Mass Spectrometry: A Review. JOURNAL OF ANALYTICAL CHEMISTRY 2022. [DOI: 10.1134/s1061934822130081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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4
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Grabarics M, Lettow M, Kirschbaum C, Greis K, Manz C, Pagel K. Mass Spectrometry-Based Techniques to Elucidate the Sugar Code. Chem Rev 2022; 122:7840-7908. [PMID: 34491038 PMCID: PMC9052437 DOI: 10.1021/acs.chemrev.1c00380] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Indexed: 12/22/2022]
Abstract
Cells encode information in the sequence of biopolymers, such as nucleic acids, proteins, and glycans. Although glycans are essential to all living organisms, surprisingly little is known about the "sugar code" and the biological roles of these molecules. The reason glycobiology lags behind its counterparts dealing with nucleic acids and proteins lies in the complexity of carbohydrate structures, which renders their analysis extremely challenging. Building blocks that may differ only in the configuration of a single stereocenter, combined with the vast possibilities to connect monosaccharide units, lead to an immense variety of isomers, which poses a formidable challenge to conventional mass spectrometry. In recent years, however, a combination of innovative ion activation methods, commercialization of ion mobility-mass spectrometry, progress in gas-phase ion spectroscopy, and advances in computational chemistry have led to a revolution in mass spectrometry-based glycan analysis. The present review focuses on the above techniques that expanded the traditional glycomics toolkit and provided spectacular insight into the structure of these fascinating biomolecules. To emphasize the specific challenges associated with them, major classes of mammalian glycans are discussed in separate sections. By doing so, we aim to put the spotlight on the most important element of glycobiology: the glycans themselves.
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Affiliation(s)
- Márkó Grabarics
- Institute
of Chemistry and Biochemistry, Freie Universität
Berlin, Arnimallee 22, 14195 Berlin, Germany
- Department
of Molecular Physics, Fritz Haber Institute
of the Max Planck Society, Faradayweg 4−6, 14195 Berlin, Germany
| | - Maike Lettow
- Institute
of Chemistry and Biochemistry, Freie Universität
Berlin, Arnimallee 22, 14195 Berlin, Germany
- Department
of Molecular Physics, Fritz Haber Institute
of the Max Planck Society, Faradayweg 4−6, 14195 Berlin, Germany
| | - Carla Kirschbaum
- Institute
of Chemistry and Biochemistry, Freie Universität
Berlin, Arnimallee 22, 14195 Berlin, Germany
- Department
of Molecular Physics, Fritz Haber Institute
of the Max Planck Society, Faradayweg 4−6, 14195 Berlin, Germany
| | - Kim Greis
- Institute
of Chemistry and Biochemistry, Freie Universität
Berlin, Arnimallee 22, 14195 Berlin, Germany
- Department
of Molecular Physics, Fritz Haber Institute
of the Max Planck Society, Faradayweg 4−6, 14195 Berlin, Germany
| | - Christian Manz
- Institute
of Chemistry and Biochemistry, Freie Universität
Berlin, Arnimallee 22, 14195 Berlin, Germany
- Department
of Molecular Physics, Fritz Haber Institute
of the Max Planck Society, Faradayweg 4−6, 14195 Berlin, Germany
| | - Kevin Pagel
- Institute
of Chemistry and Biochemistry, Freie Universität
Berlin, Arnimallee 22, 14195 Berlin, Germany
- Department
of Molecular Physics, Fritz Haber Institute
of the Max Planck Society, Faradayweg 4−6, 14195 Berlin, Germany
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5
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Lebedev AT, Vasileva ID, Samgina TY. FT-MS in the de novo top-down sequencing of natural nontryptic peptides. MASS SPECTROMETRY REVIEWS 2022; 41:284-313. [PMID: 33347655 DOI: 10.1002/mas.21678] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 11/25/2020] [Accepted: 11/25/2020] [Indexed: 06/12/2023]
Abstract
The present review covers available results on the application of FT-MS for the de novo sequencing of natural peptides of various animals: cones, bees, snakes, amphibians, scorpions, and so forth. As these peptides are usually bioactive, the animals efficiently use them as a weapon against microorganisms or higher animals including predators. These peptides represent definite interest as drugs of future generations since the mechanism of their activity is completely different in comparison with that of the modern antibiotics. Utilization of those peptides as antibiotics can eliminate the problem of the bacterial resistance development. Sequence elucidation of these bioactive peptides becomes even more challenging when the species genome is not available and little is known about the protein origin and other properties of those peptides in the study. De novo sequencing may be the only option to obtain sequence information. The benefits of FT-MS for the top-down peptide sequencing, the general approaches of the de novxxo sequencing, the difficult cases involving sequence coverage, isobaric and isomeric amino acids, cyclization of short peptides, the presence of posttranslational modifications will be discussed in the review.
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Affiliation(s)
- Albert T Lebedev
- Organic Chemistry Department, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Irina D Vasileva
- Organic Chemistry Department, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Tatiana Y Samgina
- Organic Chemistry Department, M.V. Lomonosov Moscow State University, Moscow, Russia
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6
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Kirschbaum C, Greis K, Polewski L, Gewinner S, Schöllkopf W, Meijer G, von Helden G, Pagel K. Unveiling Glycerolipid Fragmentation by Cryogenic Infrared Spectroscopy. J Am Chem Soc 2021; 143:14827-14834. [PMID: 34473927 PMCID: PMC8447261 DOI: 10.1021/jacs.1c06944] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
![]()
Mass spectrometry
is routinely employed for structure elucidation
of molecules. Structural information can be retrieved from intact
molecular ions by fragmentation; however, the interpretation of fragment
spectra is often hampered by poor understanding of the underlying
dissociation mechanisms. For example, neutral headgroup loss from
protonated glycerolipids has been postulated to proceed via an intramolecular
ring closure but the mechanism and resulting ring size have never
been experimentally confirmed. Here we use cryogenic gas-phase infrared
(IR) spectroscopy in combination with computational chemistry to unravel
the structures of fragment ions and thereby shed light on elusive
dissociation mechanisms. Using the example of glycerolipid fragmentation,
we study the formation of protonated five-membered dioxolane and six-membered
dioxane rings and show that dioxolane rings are predominant throughout
different glycerolipid classes and fragmentation channels. For comparison,
pure dioxolane and dioxane ions were generated from tailor-made dehydroxyl
derivatives inspired by natural 1,2- and 1,3-diacylglycerols and subsequently
interrogated using IR spectroscopy. Furthermore, the cyclic structure
of an intermediate fragment occurring in the phosphatidylcholine fragmentation
pathway was spectroscopically confirmed. Overall, the results contribute
substantially to the understanding of glycerolipid fragmentation and
showcase the value of vibrational ion spectroscopy to mechanistically
elucidate crucial fragmentation pathways in lipidomics.
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Affiliation(s)
- Carla Kirschbaum
- Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany.,Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany
| | - Kim Greis
- Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany.,Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany
| | - Lukasz Polewski
- Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany.,Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany
| | - Sandy Gewinner
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany
| | | | - Gerard Meijer
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany
| | - Gert von Helden
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany
| | - Kevin Pagel
- Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany.,Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany
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7
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Atik A, Arslanoglu A, Yalcin T. Gas-phase fragmentation reactions of a 7 ions containing a glutamine residue. JOURNAL OF MASS SPECTROMETRY : JMS 2021; 56:e4776. [PMID: 34268823 DOI: 10.1002/jms.4776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 06/08/2021] [Accepted: 06/15/2021] [Indexed: 06/13/2023]
Abstract
The gas-phase fragmentation reactions of the a7 ions derived from glutamine (Q) containing model heptapeptides have been studied in detail with low-energy collision-induced dissociation (CID) tandem mass spectrometry (MS/MS). Specifically, the positional effect of the Q residue has been investigated on the fragmentation reactions of a7 ions. The study involves two sets of permuted isomers of the Q containing model heptapeptides. The first set contains the QAAAAAA sequence, and the second set involves of QYAGFLV sequence, where the position of the Q residue is changed from N- to C-terminal gradually for both peptide series. An intense loss of ammonia from the a7 ions followed by internal amino acid eliminations strongly supports forming the imine-amides structure via cyclization/rearrangement reaction for all studied a7 ions. This is in agreement with the pioneering study reported by Bythell et al. (2010, 10.1021/ja101556g). A novel rearrangement reaction is detected upon fragmentation of imine-amide structure, which yields a protonated C-terminal amidated hexapeptide excluding the Q residue. A possible fragmentation mechanism was proposed to form the protonated C-terminal amidated hexapeptide, assisted via nucleophilic attack of the side chain amide nitrogen of the Q residue on its N-protonated imine carbon atom of the rearranged imine-amide structure. HIGHLIGHTS: The gas-phase fragmentation reactions of a7 ions obtained from protonated model peptides containing glutamine residue were studied by ESI-MS/MS. A rearranged imine-amide structure is the predominant even for a7 ions. Novel rearrangement reaction is observed which forms a protonated C-terminal amidated hexapeptide excluding Q residue upon fragmentation of the imine-amide structure.
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Affiliation(s)
- Ahmet Atik
- Department of Natural Sciences, Faculty of Engineering, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
- Biotechnology Group, Turgut Pharmaceuticals, Istanbul, Turkey
| | - Alper Arslanoglu
- Departmen of Molecular Biology and Genetics, Faculty of Science, Izmir Institute of Technology, Izmir, Turkey
| | - Talat Yalcin
- Department of Chemistry, Faculty of Science, Izmir Institute of Technology, Izmir, Turkey
- Integrated Research Centers, National Mass Spectrometry Application and Research Center, Izmir, Turkey
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8
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Dörner S, Schwob L, Atak K, Schubert K, Boll R, Schlathölter T, Timm M, Bülow C, Zamudio-Bayer V, von Issendorff B, Lau JT, Techert S, Bari S. Probing Structural Information of Gas-Phase Peptides by Near-Edge X-ray Absorption Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:670-684. [PMID: 33573373 DOI: 10.1021/jasms.0c00390] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Near-edge X-ray absorption mass spectrometry (NEXAMS) is an action-spectroscopy technique of growing interest for investigations into the spatial and electronic structure of biomolecules. It has been used successfully to give insights into different aspects of the photodissociation of peptides and to probe the conformation of proteins. It is a current question whether the fragmentation pathways are sensitive toward effects of conformational isomerism, tautomerism, and intramolecular interactions in gas-phase peptides. To address this issue, we studied the cationic fragments of cryogenically cooled gas-phase leucine enkephalin ([LeuEnk+H]+) and methionine enkephalin ([MetEnk+H]+) produced upon soft X-ray photon absorption at the carbon, nitrogen, and oxygen K-edges. The interpretation of the experimental ion yield spectra was supported by density-functional theory and restricted-open-shell configuration interaction with singles (DFT/ROCIS) calculations. The analysis revealed several effects that could not be rationalized based on the peptide's amino acid sequences alone. Clear differences between the partial ion yields measured for both peptides upon C 1s → π*(C═C) excitations in the aromatic amino acid side chains give evidence for a sulfur-aromatic interaction between the methionine and phenylalanine side chain of [MetEnk+H]+. Furthermore, a peak associated with N 1s → π*(C═N) transitions, linked to a tautomeric keto-to-enol conversion of peptide bonds, was only present in the photon energy resolved ion yield spectra of [MetEnk+H]+.
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Affiliation(s)
- Simon Dörner
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Lucas Schwob
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Kaan Atak
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Kaja Schubert
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Rebecca Boll
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Thomas Schlathölter
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Martin Timm
- Abteilung Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - Christine Bülow
- Abteilung Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - Vicente Zamudio-Bayer
- Abteilung Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - Bernd von Issendorff
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| | - J Tobias Lau
- Abteilung Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| | - Simone Techert
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
- Institut für Röntgenphysik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Sadia Bari
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
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9
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Martin Somer A, Macaluso V, Barnes GL, Yang L, Pratihar S, Song K, Hase WL, Spezia R. Role of Chemical Dynamics Simulations in Mass Spectrometry Studies of Collision-Induced Dissociation and Collisions of Biological Ions with Organic Surfaces. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:2-24. [PMID: 32881516 DOI: 10.1021/jasms.9b00062] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In this article, a perspective is given of chemical dynamics simulations of collisions of biological ions with surfaces and of collision-induced dissociation (CID) of ions. The simulations provide an atomic-level understanding of the collisions and, overall, are in quite good agreement with experiment. An integral component of ion/surface collisions is energy transfer to the internal degrees of freedom of both the ion and the surface. The simulations reveal how this energy transfer depends on the collision energy, incident angle, biological ion, and surface. With energy transfer to the ion's vibration fragmentation may occur, i.e. surface-induced dissociation (SID), and the simulations discovered a new fragmentation mechanism, called shattering, for which the ion fragments as it collides with the surface. The simulations also provide insight into the atomistic dynamics of soft-landing and reactive-landing of ions on surfaces. The CID simulations compared activation by multiple "soft" collisions, resulting in random excitation, versus high energy single collisions and nonrandom excitation. These two activation methods may result in different fragment ions. Simulations provide fragmentation products in agreement with experiments and, hence, can provide additional information regarding the reaction mechanisms taking place in experiment. Such studies paved the way on using simulations as an independent and predictive tool in increasing fundamental understanding of CID and related processes.
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Affiliation(s)
- Ana Martin Somer
- Departamento de Química, Facultad de Ciencias, Módulo 13 Universidad Autónoma de Madrid, Campus de Excelencia UAM-CSIC Cantoblanco, 28049 Madrid, Spain
| | - Veronica Macaluso
- LAMBE, Univ Evry, CNRS, CEA, Université Paris-Saclay, 91025 Evry, France
| | - George L Barnes
- Department of Chemistry and Biochemistry, Siena College, Loudonville, New York 12211, United States
| | - Li Yang
- MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, P.R. China
| | - Subha Pratihar
- Department of Chemistry and Biochemistry Texas Tech University, Lubbock, Texas 79409, United States
| | - Kihyung Song
- Department of Chemistry, Korea National University of Education, Chungbuk 28644, Republic of Korea
| | - William L Hase
- Department of Chemistry and Biochemistry Texas Tech University, Lubbock, Texas 79409, United States
| | - Riccardo Spezia
- Sorbonne Université, CNRS, Laboratoire de Chimie Théorique, LCT, 4, Place Jussieu, Paris, 75252 Cedex 05, France
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10
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Lettow M, Mucha E, Manz C, Thomas DA, Marianski M, Meijer G, von Helden G, Pagel K. The role of the mobile proton in fucose migration. Anal Bioanal Chem 2019; 411:4637-4645. [PMID: 30826852 PMCID: PMC6611747 DOI: 10.1007/s00216-019-01657-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 01/11/2019] [Accepted: 01/30/2019] [Indexed: 11/25/2022]
Abstract
Fucose migration reactions represent a substantial challenge in the analysis of fucosylated glycan structures by mass spectrometry. In addition to the well-established observation of transposed fucose residues in glycan-dissociation product ions, recent experiments show that the rearrangement can also occur in intact glycan ions. These results suggest a low-energy barrier for migration of the fucose residue and broaden the relevance of fucose migration to include other types of mass spectrometry experiments, including ion mobility-mass spectrometry and ion spectroscopy. In this work, we utilize cold-ion infrared spectroscopy to provide further insight into glycan scrambling in intact glycan ions. Our results show that the mobility of the proton is a prerequisite for the migration reaction. For the prototypical fucosylated glycans Lewis x and blood group antigen H-2, the formation of adduct ions or the addition of functional groups with variable proton affinity yields significant differences in the infrared spectra. These changes correlate well with the promotion or inhibition of fucose migration through the presence or absence of a mobile proton. ![]()
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Affiliation(s)
- Maike Lettow
- Department of Molecular Physics, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany.,Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany
| | - Eike Mucha
- Department of Molecular Physics, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany.,Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany
| | - Christian Manz
- Department of Molecular Physics, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany.,Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany
| | - Daniel A Thomas
- Department of Molecular Physics, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany
| | - Mateusz Marianski
- Department of Molecular Physics, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany.,Hunter College, The City University of New York, 695 Park Ave, New York, NY, 10065, USA
| | - Gerard Meijer
- Department of Molecular Physics, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany
| | - Gert von Helden
- Department of Molecular Physics, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany
| | - Kevin Pagel
- Department of Molecular Physics, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany. .,Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany.
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11
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Manz C, Grabarics M, Hoberg F, Pugini M, Stuckmann A, Struwe WB, Pagel K. Separation of isomeric glycans by ion mobility spectrometry – the impact of fluorescent labelling. Analyst 2019; 144:5292-5298. [DOI: 10.1039/c9an00937j] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Bloodgroup oligosaccharides have been derivatized with labels common in HPLC and evaluated regarding their ion mobility behaviour.
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Affiliation(s)
- Christian Manz
- Institute of Chemistry and Biochemistry
- Freie Universität Berlin
- 14195 Berlin
- Germany
- Fritz Haber Institute of the Max Planck Society
| | - Márkó Grabarics
- Institute of Chemistry and Biochemistry
- Freie Universität Berlin
- 14195 Berlin
- Germany
- Fritz Haber Institute of the Max Planck Society
| | - Friederike Hoberg
- Fritz Haber Institute of the Max Planck Society
- Department of Molecular Physics
- 14195 Berlin
- Germany
| | - Michele Pugini
- Institute of Chemistry and Biochemistry
- Freie Universität Berlin
- 14195 Berlin
- Germany
- Fritz Haber Institute of the Max Planck Society
| | - Alexandra Stuckmann
- Institute of Chemistry and Biochemistry
- Freie Universität Berlin
- 14195 Berlin
- Germany
| | - Weston B. Struwe
- Oxford Glycobiology Institute
- Department of Biochemistry
- University of Oxford
- Oxford OX1 3QU
- UK
| | - Kevin Pagel
- Institute of Chemistry and Biochemistry
- Freie Universität Berlin
- 14195 Berlin
- Germany
- Fritz Haber Institute of the Max Planck Society
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12
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Nelson CR, Abutokaikah MT, Harrison AG, Bythell BJ. Proton Mobility in b₂ Ion Formation and Fragmentation Reactions of Histidine-Containing Peptides. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:487-497. [PMID: 26602904 DOI: 10.1007/s13361-015-1298-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 10/13/2015] [Accepted: 10/19/2015] [Indexed: 06/05/2023]
Abstract
A detailed energy-resolved study of the fragmentation reactions of protonated histidine-containing peptides and their b2 ions has been undertaken. Density functional theory calculations were utilized to predict how the fragmentation reactions occur so that we might discern why the mass spectra demonstrated particular energy dependencies. We compare our results to the current literature and to synthetic b2 ion standards. We show that the position of the His residue does affect the identity of the subsequent b2 ion (diketopiperazine versus oxazolone versus lactam) and that energy-resolved CID can distinguish these isomeric products based on their fragmentation energetics. The histidine side chain facilitates every major transformation except trans-cis isomerization of the first amide bond, a necessary prerequisite to diketopiperazine b2 ion formation. Despite this lack of catalyzation, trans-cis isomerization is predicted to be facile. Concomitantly, the subsequent amide bond cleavage reaction is rate-limiting.
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Affiliation(s)
- Carissa R Nelson
- Department of Chemistry and Biochemistry, University of Missouri, St. Louis, MO, 63121, USA
| | - Maha T Abutokaikah
- Department of Chemistry and Biochemistry, University of Missouri, St. Louis, MO, 63121, USA
| | - Alex G Harrison
- Department of Chemistry, University of Toronto, Toronto, ON, M5S 1A1, Canada
| | - Benjamin J Bythell
- Department of Chemistry and Biochemistry, University of Missouri, St. Louis, MO, 63121, USA.
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13
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Plaviak A, Osburn S, Patterson K, van Stipdonk MJ. Even-electron [M-H](+) ions generated by loss of AgH from argentinated peptides with N-terminal imine groups. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:69-80. [PMID: 26661972 DOI: 10.1002/rcm.7415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 09/24/2015] [Accepted: 10/04/2015] [Indexed: 06/05/2023]
Abstract
RATIONALE Experiments were performed to probe the creation of apparent even-electron, [M-H](+) ions by CID of Ag-cationized peptides with N-terminal imine groups (Schiff bases). METHODS Imine-modified peptides were prepared using condensation reactions with aldehydes. Ag(+) -cationized precursors were generated by electrospray ionization (ESI). Tandem mass spectrometry (MS(n) ) and collision-induced dissociation (CID) were performed using a linear ion trap mass spectrometer. RESULTS Loss of AgH from peptide [M + Ag](+) ions, at the MS/MS stage, creates closed-shell [M-H](+) ions from imine-modified peptides. Isotope labeling unambiguously identifies the imine C-H group as the source of H eliminated in AgH. Subsequent CID of the [M-H](+) ions generated sequence ions that are analogous to those produced from [M + H](+) ions of the imine-modified peptides. CONCLUSIONS Experiments show (a) formation of novel even-electron peptide cations by CID and (b) the extent to which sequence ions (conventional b, a and y ions) are generated from peptides with fixed charge site and thus lacking a conventional mobile proton.
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Affiliation(s)
- Alexandra Plaviak
- Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Ave, Pittsburgh, PA, 15282, USA
| | - Sandra Osburn
- Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Ave, Pittsburgh, PA, 15282, USA
| | - Khiry Patterson
- Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Ave, Pittsburgh, PA, 15282, USA
| | - Michael J van Stipdonk
- Department of Chemistry and Biochemistry, Duquesne University, 600 Forbes Ave, Pittsburgh, PA, 15282, USA
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14
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Ranković ML, Canon F, Nahon L, Giuliani A, Milosavljević AR. Photoinduced fragmentation of gas-phase protonated leucine- enkephalin peptide in the VUV range. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/1742-6596/635/1/012034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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15
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Chang J, Chen ZL, Wang Z, Shen JM, Chen Q, Kang J, Yang L, Liu XW, Nie CX. Ozonation degradation of microcystin-LR in aqueous solution: intermediates, byproducts and pathways. WATER RESEARCH 2014; 63:52-61. [PMID: 24981743 DOI: 10.1016/j.watres.2014.06.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 06/05/2014] [Accepted: 06/06/2014] [Indexed: 06/03/2023]
Abstract
The intermediates and byproducts formed during the ozonation of microcystin-LR (MC-LR, m/z = 995.5) and the probable degradation pathway were investigated at different initial molar ratios of ozone to MC-LR ([O3]0/[MC-LR]0). Seven reaction intermediates with m/z ≥ 795.4 were observed by LC/MS, and four of them (m/z = 815.4, 827.3, 853.3 and 855.3) have not been previously reported. Meanwhile, six aldehyde-based byproducts with molecular weights of 30-160 were detected for the first time. Intermediates structures demonstrated that ozone reacted with two sites of MC-LR: the diene bonds in the Adda side chain and the Mdha amino acid in the cyclic structure. The fragment from the Adda side chain oxidative cleavage could be further oxidized to an aldehyde with a molecular weight of 160 at low [O3]0/[MC-LR]0. Meanwhile, the polypeptide structure of MC-LR was difficult to be further oxidized, unless [O3]0/[MC-LR]0 > 10. After further oxidation of the intermediates, five other aldehyde-based byproducts were detected by GC/MS: formaldehyde, acetaldehyde, isovaleraldehyde, glyoxal and methylglyoxal. Formaldehyde, isovaleraldehyde and methylglyoxal were the dominant species. The yields of the aldehydes varied greatly, depending on the value of [O3]0/[MC-LR]0.
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Affiliation(s)
- Jing Chang
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Zhong-lin Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Zhe Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Ji-min Shen
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
| | - Qian Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Jing Kang
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Lei Yang
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Xiao-wei Liu
- Institute of Municipal Engineering, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China
| | - Chang-xin Nie
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
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16
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Lebedev AT, Damoc E, Makarov AA, Samgina TY. Discrimination of Leucine and Isoleucine in Peptides Sequencing with Orbitrap Fusion Mass Spectrometer. Anal Chem 2014; 86:7017-22. [DOI: 10.1021/ac501200h] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Albert T. Lebedev
- Chemistry
Department, M.V. Lomonosov Moscow State University, Leninskie
Gory 1/3, Moscow, 119991, Russia
| | - Eugen Damoc
- ThermoFisher Scientific (Bremen) GmbH, Hanna-Kunath Strasse 11, 28199, Bremen, Germany
| | - Alexander A. Makarov
- ThermoFisher Scientific (Bremen) GmbH, Hanna-Kunath Strasse 11, 28199, Bremen, Germany
| | - Tatiana Yu. Samgina
- Chemistry
Department, M.V. Lomonosov Moscow State University, Leninskie
Gory 1/3, Moscow, 119991, Russia
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17
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The fate of b-ions in the two worlds of collision-induced dissociation. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:2843-8. [DOI: 10.1016/j.bbapap.2013.08.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 08/14/2013] [Accepted: 08/16/2013] [Indexed: 11/21/2022]
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18
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Zhao J, Lau JKC, Grzetic J, Verkerk UH, Oomens J, Siu KWM, Hopkinson AC. Structures of a(n)* ions derived from protonated pentaglycine and pentaalanine: results from IRMPD spectroscopy and DFT calculations. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2013; 24:1957-1968. [PMID: 24026976 DOI: 10.1007/s13361-013-0728-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 08/02/2013] [Accepted: 08/05/2013] [Indexed: 06/02/2023]
Abstract
Infrared multiple-photon dissociation (IRMPD) spectroscopy and DFT calculations have been used to probe the most stable structures of a3(*) and a4(*) ions derived from both protonated pentaglycine (denoted G5) and pentaalanine (A5). The a3(*) and a4(*) ions derived from protonated A5 feature a CHR=N-CHR'- group at the N-terminus and an oxazolone ring at the C-terminus, as proposed previously [J. Am. Soc. Mass Spectrom. 19, 1788-1798 (2008)]. The isomeric a4(*) ion derived from A5 with a 3,5-dihydro-4H-imidazol-4-one ring structure was calculated to have a slightly better energy than the oxazolone, but the barrier to its formation is higher and there was no evidence of this ion in the IRMPD spectrum. By contrast, the a4(*) and [a4 - H2O](+) (denoted a4(0)) ions from G5 gave strikingly similar IRMPD spectra and both have the 3,5-dihydro-4H-imidazol-4-one ring structure similar to that recently reported for the [GGGG + H - H2O](+) ion [Int. J. Mass Spectrom. 316-318, 268-272 (2012)]. In the absence of a solvent molecule, the pathway to the oxazolone is calculated to be lower than those to thermodynamically more stable products, the a4(0) and the a4(*) with the 3,5-dihydro-4H-imidazol-4-one ring structure. Incorporation of one water molecule is sufficient to reduce the barrier to formation of the a4(0) of G5 to below that for formation of the oxazolone. On the equivalent potential energy surface for protonated A5 the barrier to formation of the a4(0) ion is 12.3 kcal mol(-1) higher than that for oxazolone formation and the a4(0) ion is not observed experimentally.
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Affiliation(s)
- Junfang Zhao
- Department of Chemistry and Centre for Research in Mass Spectrometry, York University, Toronto, ON, M3J 1P3, Canada
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19
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Harrison AG. Fragmentation reactions of methionine-containing protonated octapeptides and fragment ions therefrom: an energy-resolved study. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2013; 24:1555-1564. [PMID: 23943431 DOI: 10.1007/s13361-013-0706-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 05/27/2013] [Accepted: 06/03/2013] [Indexed: 06/02/2023]
Abstract
The fragmentation reactions of the MH(+) ions as well as the b7, a7, and a7* ions derived therefrom have been studied in detail for the octapeptides MAAAAAAA, AAMAAAAA, AAAAMAAA, and AAAAAAMA. Ionization was by electrospray using a QqToF mass spectrometer, which allowed a study of the evolution of the fragmentation channels as a function of the collision energy. Not surprisingly, the product ion mass spectra for the b7 ions are independent of the original precursor sequence, indicating macrocyclization and reopening to the same mixture of protonated oxazolones prior to fragmentation. The results show that this sequence scrambling results in a distinct preference to place the Met residue in the C-terminal position of the protonated oxazolones. The a7 and a7* ions also produce product ion mass spectra independent of the original peptide sequence. The results for the a7 ions indicate that fragmentation occurs primarily from an amide structure analogous to that observed for a4 ions (Bythell et al. in J Am Chem Soc 132:14766-14779, 2010). Clearly, the rearrangement reaction they have proposed applies equally well to an ions as large as a7. The major fragmentation modes of the MH(+) ions at low collision energies produce b7, b6, and b5 ions. As the collision energy is increased further fragmentation of these primary products produces, in part, non-direct sequence ions, which become prominent at lower m/z values, particularly for the peptides with the Met residue near the N-terminus.
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Affiliation(s)
- Alex G Harrison
- Department of Chemistry, University of Toronto, Toronto, ON, M5S 3H6, Canada,
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20
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Bianco G, Labella C, Pepe A, Cataldi TRI. Scrambling of autoinducing precursor peptides investigated by infrared multiphoton dissociation with electrospray ionization and Fourier transform ion cyclotron resonance mass spectrometry. Anal Bioanal Chem 2012. [PMID: 23208287 DOI: 10.1007/s00216-012-6583-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Two synthetic precursor peptides, H(2)N-CVGIW and H(2)N-LVMCCVGIW, involved in the quorum sensing of Lactobacillus plantarum WCFS1, were characterized by mass spectrometry (MS) with electrospray ionization and 7-T Fourier transform ion cyclotron resonance (ESI-FTICR) instrument. Cell-free bacterial supernatant solutions were analyzed by reversed-phase liquid chromatography with ESI-FTICR MS to verify the occurrence of both pentapeptide and nonapeptide in the bacterial broth. The structural characterization of both protonated peptides was performed by infrared multiphoton dissociation using a continuous CO(2) laser source at a wavelength of 10.6 μm. As their fragmentation behavior cannot be directly derived from the primary peptide structure, all anomalous fragments were interpreted as neutral loss of amino acids from the interior of both peptides, i.e., loss of V, G, VG and M, MC, V, CC, from H(2)N-CVGIW and H(2)N-LVMCCVGIW, respectively. Mechanisms of this scrambling are proposed. FTICR MS provides accurate masses of all fragment ions with very low absolute mass errors (<1.6 ppm), which facilitated the reliable assignment of their elemental compositions. The resolving power was more than sufficient to resolve closely isobaric product ions with routine subparts per million mass accuracies. Only the occurrence of pentapeptide was found in the cell-free culture of L. plantarum, grown in Waymouth's medium broth, with a low content of 5.2 ± 2.6 μM by external calibration. Most of it was present as oxidized H(2)N-CVGIW, that is, the soluble disulfide pentapeptide with a level tenfold higher (i.e., 50 ± 4 μM, n = 3).
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Affiliation(s)
- Giuliana Bianco
- Dipartimento di Scienze, Università degli Studi della Basilicata, Potenza, Italy
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21
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Banerjee S, Mazumdar S. Selective deletion of the internal lysine residue from the peptide sequence by collisional activation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2012; 23:1967-1980. [PMID: 22923014 DOI: 10.1007/s13361-012-0456-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 07/15/2012] [Accepted: 07/20/2012] [Indexed: 06/01/2023]
Abstract
The gas-phase peptide ion fragmentation chemistry is always the center of attraction in proteomics to analyze the amino acid sequence of peptides and proteins. In this work, we describe the formation of an anomalous fragment ion, which corresponds to the selective deletion of the internal lysine residue from a series of lysine containing peptides upon collisional activation in the ion trap. We detected several water-loss fragment ions and the maximum number of water molecules lost from a particular fragment ion was equal to the number of lysine residues in that fragment. As a consequence of this water-loss phenomenon, internal lysine residues were found to be deleted from the peptide ion. The N,N-dimethylation of all the amine functional groups of the peptide stopped the internal lysine deletion reaction, but selective N-terminal α-amino acetylation had no effect on this process indicating involvement of the side chains of the lysine residues. The detailed mechanism of the lysine deletion was investigated by multistage CID of the modified and unmodified peptides, by isotope labeling and by energy resolved CID studies. The results suggest that the lysine deletion might occur through a unimolecular multistep mechanism involving a seven-membered cyclic imine intermediate formed by the loss of water from a lysine residue in the protonated peptide. This intermediate subsequently undergoes degradation reaction to deplete the interior imine ring from the peptide backbone leading to the deletion of an internal lysine residue.
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Affiliation(s)
- Shibdas Banerjee
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai, India
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22
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González-Magaña O, Reitsma G, Tiemens M, Boschman L, Hoekstra R, Schlathölter T. Near-Edge X-ray Absorption Mass Spectrometry of a Gas-Phase Peptide. J Phys Chem A 2012; 116:10745-51. [DOI: 10.1021/jp307527b] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- O. González-Magaña
- KVI Atomic and Molecular Physics, University of Groningen, Zernikelaan 25, 9747AA Groningen,
The Netherlands
| | - G. Reitsma
- KVI Atomic and Molecular Physics, University of Groningen, Zernikelaan 25, 9747AA Groningen,
The Netherlands
| | - M. Tiemens
- KVI Atomic and Molecular Physics, University of Groningen, Zernikelaan 25, 9747AA Groningen,
The Netherlands
| | - L. Boschman
- KVI Atomic and Molecular Physics, University of Groningen, Zernikelaan 25, 9747AA Groningen,
The Netherlands
- Kapteyn
Astronomical Institute, University of Groningen, Landleven 12, 9747AD Groningen,
The Netherlands
| | - R. Hoekstra
- KVI Atomic and Molecular Physics, University of Groningen, Zernikelaan 25, 9747AA Groningen,
The Netherlands
| | - T. Schlathölter
- KVI Atomic and Molecular Physics, University of Groningen, Zernikelaan 25, 9747AA Groningen,
The Netherlands
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23
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Yang H, Good DM, van der Spoel D, Zubarev RA. Carbonyl charge solvation patterns may relate to fragmentation classes in collision-activated dissociation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2012; 23:1319-1325. [PMID: 22689324 DOI: 10.1007/s13361-012-0418-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 05/12/2012] [Accepted: 05/13/2012] [Indexed: 06/01/2023]
Abstract
Here, we investigate the hypothesis that the origin of Class I fragmentation in tryptic peptide dications corresponding to the cleavage of the first two amino acids from the N-terminus is due to a dominant charge solvation pattern. Molecular dynamics simulations (MDS) of model A(n)R dications confirmed the existence of a persistent solvation of the protonated N-terminus on the second backbone carbonyl. Additionally, MDS predicted a new distinct fragmentation class corresponding to the loss of two amino acids from the C-terminus. This prediction was confirmed experimentally at very low excitation levels. The pattern produced by electron transfer dissociation of the same dications gave markedly decreased cleavage frequencies at the second peptide bond, which, within the non-local fragmentation mechanism, supports the preferential charge solvation on the second carbonyl. Taken together, these results confirm the role of a charge solvation pattern in the origin of fragmentation classes.
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Affiliation(s)
- Hongqian Yang
- Division of Physiological Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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24
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Dong NP, Liang YZ, Yi LZ. Investigation of scrambled ions in tandem mass spectra. Part 1. Statistical characterization. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2012; 23:1209-1220. [PMID: 22539146 DOI: 10.1007/s13361-012-0380-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 03/20/2012] [Accepted: 03/22/2012] [Indexed: 05/31/2023]
Abstract
Scrambled ions have become the focus of recent investigations of peptide fragmentation. Here, an investigation of more than 390,000 high quality CID mass spectra is presented to explore the extent of scrambled ions in mass spectra and the possible fragmentation rules during scramble reactions. For the former, scrambled ions generally make up more than 10 % of mass spectra in number, although the abundances are less than 0.1 of the base peak. For the latter, relatively preferential re-opening sites were found for aliphatic residues Ala, Ile, Leu, and other residues such as Met, Gln, Ser, Phe, and Thr, whereas disfavored sites were found for basic residues Arg, Lys, and His, and Trp for both scrambled b and a ions. Similar preferential order in re-opening reaction was found in the reaction of losing internal residues when cleavage occurs at C-terminal side of 20 residues. However, when cleavage occurs at N-terminal side, Glu, Phe, and Trp become the most preferential sites. These results provide a deep insight into cleavage rules during scramble reactions for prediction of peptide mass spectra. Also, an additional investigation of whether scrambled ions could help discriminate false identifications from correct identifications was performed. Probing the number fraction of scrambled ions in falsely and correctly interpreted spectra and analyzing the correlation between scrambled ions and SEQUEST scores XCorr and Sp showed scrambled ions could at some extent help improve the discrimination in singly charged identifications, whereas no improvement was found for multiply charged results.
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Affiliation(s)
- Nai-ping Dong
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, People's Republic of China
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25
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Wassermann TN, Boyarkin OV, Paizs B, Rizzo TR. Conformation-specific spectroscopy of peptide fragment ions in a low-temperature ion trap. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2012; 23:1029-1045. [PMID: 22460621 DOI: 10.1007/s13361-012-0368-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 02/17/2012] [Accepted: 02/23/2012] [Indexed: 05/31/2023]
Abstract
We have applied conformer-selective infrared-ultraviolet (IR-UV) double-resonance photofragment spectroscopy at low temperatures in an ion trap mass spectrometer for the spectroscopic characterization of peptide fragment ions. We investigate b- and a-type ions formed by collision-induced dissociation from protonated leucine-enkephalin. The vibrational analysis and assignment are supported by nitrogen-15 isotopic substitution of individual amino acid residues and assisted by density functional theory calculations. Under such conditions, b-type ions of different size are found to appear exclusively as linear oxazolone structures with protonation on the N-terminus, while a rearrangement reaction is confirmed for the a (4) ion in which the side chain of the C-terminal phenylalanine residue is transferred to the N-terminal side of the molecule. The vibrational spectra that we present here provide a particularly stringent test for theoretical approaches.
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Affiliation(s)
- Tobias N Wassermann
- Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland
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26
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Harrison AG. Fragmentation reactions of b(5) and a (5) ions containing proline--the structures of a(5) ions. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2012; 23:594-601. [PMID: 21952775 DOI: 10.1007/s13361-011-0232-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 08/01/2011] [Accepted: 08/11/2011] [Indexed: 05/31/2023]
Abstract
A detailed study has been made of the b(5) and a(5) ions derived from the amides H-Ala-Ala-Ala-Ala-Pro-NH(2), H-Ala-Ala-Ala-Pro-Ala-NH(2), and H-Ala-Ala-Pro-Ala-Ala-NH(2). From quasi-MS(3) experiments it is shown that the product ion mass spectra of the three b(5) ions are essentially identical, indicating macrocyclization/reopening to produce a common mixture of intermediates prior to fragmentation. This is in agreement with numerous recent studies of sequence scrambling in b ions. By contrast, the product ion mass spectra for the a(5) ions show substantial differences, indicating significant differences in the mixture of structures undergoing fragmentation for these three species. The results are interpreted in terms of a mixture of classical substituted iminium ions as well as protonated C-terminal amides formed by cyclization/rearrangement as reported recently for a(4) ions (Bythell, Maître , Paizs, J . Am. Chem. Soc. 2010, 132, 14761-14779). Novel fragment ions observed upon fragmentation of the a(5) ions are protonated H-Pro-NH(2) and H-Pro-Ala-NH(2) which arise by fragmentation of the amides. The observation of these products provides strong experimental evidence for the cyclization/rearrangement reaction to form amides and shows that it also applies to a(5) ions.
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Affiliation(s)
- Alex G Harrison
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada.
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27
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Tirado M, Rutters J, Chen X, Yeung A, van Maarseveen J, Eyler JR, Berden G, Oomens J, Polfer NC. Disfavoring macrocycle b fragments by constraining torsional freedom: the "twisted" case of QWFGLM b6. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2012; 23:475-482. [PMID: 22219043 DOI: 10.1007/s13361-011-0315-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 12/02/2011] [Accepted: 12/04/2011] [Indexed: 05/31/2023]
Abstract
While recent studies have shown that for some peptides, such as oligoglycines and Leu-enkephalin, mid-sized b fragment ions exist as a mixture of oxazolone and macrocycle structures, other primary structure motifs, such as QWFGLM, are shown to exclusively give rise to macrocycle structures. The aim of this study was to determine if certain amino acid residues are capable of suppressing macrocycle formation in the corresponding b fragment. The residues proline and 4-aminomethylbenzoic acid (4AMBz) were chosen because of their intrinsic rigidity, in the expectation that limited torsional flexibility may impede "head-to-tail" macrocycle formation. The presence of oxazolone versus macrocycle b(6) fragment structures was validated by infrared multiple photon dissociation (IRMPD) spectroscopy, using the free electron laser FELIX. It is confirmed that proline disfavors macrocycle formation in the cases of QPWFGLM b(7) and in QPFGLM b(6). The 4AMBz substitution experiments show that merely QWFG(4AMBz)M b(6), with 4AMBz in the fifth position, exhibits a weak oxazolone band. This effect is likely ascribed to a stabilization of the oxazolone structure, due to an extended oxazolone ring-phenyl π-electron system, not due to the rigidity of the 4AMBz residue. These results show that some primary structures have an intrinsic propensity to form macrocycle structures, which is difficult to disrupt, even using residues with limited torsional flexibility.
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Affiliation(s)
- Marcus Tirado
- Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, FL, 32611-7200, USA
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Electrospray ionization mass spectrometry: a technique to access the information beyond the molecular weight of the analyte. Int J Anal Chem 2011; 2012:282574. [PMID: 22611397 PMCID: PMC3348530 DOI: 10.1155/2012/282574] [Citation(s) in RCA: 268] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 10/23/2011] [Accepted: 11/09/2011] [Indexed: 01/12/2023] Open
Abstract
The Electrospray Ionization (ESI) is a soft ionization technique extensively used for production of gas phase ions (without fragmentation) of thermally labile large supramolecules. In the present review we have described the development of Electrospray Ionization mass spectrometry (ESI-MS) during the last 25 years in the study of various properties of different types of biological molecules. There have been extensive studies on the mechanism of formation of charged gaseous species by the ESI. Several groups have investigated the origin and implications of the multiple charge states of proteins observed in the ESI-mass spectra of the proteins. The charged analytes produced by ESI can be fragmented by activating them in the gas-phase, and thus tandem mass spectrometry has been developed, which provides very important insights on the structural properties of the molecule. The review will highlight recent developments and emerging directions in this fascinating area of research.
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29
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Zhang J, Al-Eryani R, Ball HL. Mass spectrometry analysis of 2-nitrophenylhydrazine carboxy derivatized peptides. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2011; 22:1958-1967. [PMID: 21952763 DOI: 10.1007/s13361-011-0220-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 07/14/2011] [Accepted: 07/19/2011] [Indexed: 05/31/2023]
Abstract
Peptides with two or more basic residues, including those with post-translational modifications (PTMs), such as methylation and phosphorylation, can be highly hydrophilic and, therefore, are often difficult to be retained on a reversed-phase (RP) column. In addition, these highly hydrophilic peptides may carry two or more positive charges, which often fragment poorly upon collisionally activated dissociation (CAD), resulting in few sequence-specific ions. C-terminal rearrangement may also occur during CAD. Furthermore, some PTMs are labile and tend to be lost when subjected to CAD as is the case with phosphorylation on serine or threonine. To overcome the difficulties of separation, detection, and fragmentation of highly hydrophilic peptides, we report here the effect of carboxy group derivatization with 2-nitrophenylhydrazine (this strategy will be called NPHylation for simplicity). NPHylation significantly increases the hydrophobicity of the peptides, eliminates C-terminal rearrangement in all cases, and offers enhanced sensitivity in some cases. In addition, the CAD spectra of the resulting NPHylated peptides carry more sequence-specific ions due to significant reduction of sequence scrambling as observed for peptide EHAGVISVL. Furthermore, the different carboxy derivatives of this peptide undergo sequence scrambling to varying degrees, which clearly demonstrates that the C-terminus has a profound effect on peptide fragmentation. Finally, sequence scrambling is a charge dependent phenomenon, which affects CAD of doubly charged peptides far more than their singly charged counterparts.
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Affiliation(s)
- Junmei Zhang
- Protein Chemistry Technology Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-8816, USA
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30
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Watson HM, Vincent JB, Cassady CJ. Effects of transition metal ion coordination on the collision-induced dissociation of polyalanines. JOURNAL OF MASS SPECTROMETRY : JMS 2011; 46:1099-1107. [PMID: 22124980 DOI: 10.1002/jms.1992] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Transition metal-polyalanine complexes were analyzed in a high-capacity quadrupole ion trap after electrospray ionization. Polyalanines have no polar amino acid side chains to coordinate metal ions, thus allowing the effects metal ion interaction with the peptide backbone to be explored. Positive mode mass spectra produced from peptides mixed with salts of the first row transition metals Cr(III), Fe(II), Fe(III), Co(II), Ni(II), Cu(I), and Cu(II) yield singly and doubly charged metallated ions. These precursor ions undergo collision-induced dissociation (CID) to give almost exclusively metallated N-terminal product ions whose types and relative abundances depend on the identity of the transition metal. For example, Cr(III)-cationized peptides yield CID spectra that are complex and have several neutral losses, whereas Fe(III)-cationized peptides dissociate to give intense non-metallated products. The addition of Cu(II) shows the most promise for sequencing. Spectra obtained from the CID of singly and doubly charged Cu-heptaalanine ions, [M + Cu - H](+) and [M + Cu](2+) , are complimentary and together provide cleavage at every residue and no neutral losses. (This contrasts with [M + H](+) of heptaalanine, where CID does not provide backbone ions to sequence the first three residues.) Transition metal cationization produces abundant metallated a-ions by CID, unlike protonated peptides that produce primarily b- and y-ions. The prominence of metallated a-ions is interesting because they do not always form from b-ions. Tandem mass spectrometry on metallated (Met = metal) a- and b-ions indicate that [b(n) + Met - H](2+) lose CO to form [a(n) + Met - H](2+), mimicking protonated structures. In contrast, [a(n) + Met - H](2+) eliminate an amino acid residue to form [a(n-1) + Met - H](2+), which may be useful in sequencing.
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Affiliation(s)
- Heather M Watson
- Department of Chemistry, The University of Alabama, Tuscaloosa, AL, USA
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31
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Chen X, Tirado M, Steill JD, Oomens J, Polfer NC. Cyclic peptide as reference system for b ion structural analysis in the gas phase. JOURNAL OF MASS SPECTROMETRY : JMS 2011; 46:1011-1015. [PMID: 22012667 DOI: 10.1002/jms.1982] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Infrared multiple photon dissociation spectroscopy and hydrogen/deuterium exchange methods are used to confirm the macrocylic structure of a b(6) peptide fragment by direct comparison with a synthetically made cyclic peptide. The acetylation of the peptide N-terminus results in the inhibition of the macrocyclic formation, supporting the "head-to-tail" cyclization mechanism. Differences in hydrogen/deuterium exchange rates for macrocyclic and oxazalone structure peptide fragments are interpreted to be a result of the complex interplay of multiple basic sites in the peptide fragment, supporting the relay mechanism for deuterium exchange with CH(3)OD.
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Affiliation(s)
- Xian Chen
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
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32
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Saminathan IS, Zhao J, Siu KWM, Hopkinson AC. Doubly charged protonated a ions derived from small peptides. Phys Chem Chem Phys 2011; 13:18307-14. [PMID: 21773645 DOI: 10.1039/c1cp21522a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Protonated a(2) and a(3) (therefore doubly charged) ions in which both charges lie on the peptide backbone are formed in collision-induced dissociations of [La(III)(peptide)(CH(3)CN)(m)](3+) complexes. Abundant (a(3)+H)(2+) ions are formed from triproline (PPP) and peptides with a proline residue at the N-terminus; these peptides are the most effective in producing ions of the type (a(2)+H)(2+) and (a(3)+H)(2+). A systematic study of the effect of the location of the proline residue and other residues of aliphatic amino acids on the generation of protonated a ions is reported. Density functional theory calculations at B3LYP/6-311++G(d,p) gave the proton affinity of the a(3) ion derived from PPP to be 167.6 kcal mol(-1), 2.6 kcal mol(-1) higher than that of water. The protonated a(2) ions of diglycine and diproline and a(3) ions of triglycine have lower proton affinities and are only observed in lower abundances, possibly due to proton transfer to water in ion-molecule reactions.
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Affiliation(s)
- Irine S Saminathan
- Department of Chemistry and Centre for Research in Mass Spectrometry, York University, 4700 Keele Street, Toronto, Canada M3J 1P3
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33
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Verkerk UH, Zhao J, Van Stipdonk MJ, Bythell BJ, Oomens J, Hopkinson AC, Siu KM. Structure of the [M + H – H2O]+ Ion from Tetraglycine: A Revisit by Means of Density Functional Theory and Isotope Labeling. J Phys Chem A 2011; 115:6683-7. [DOI: 10.1021/jp202820h] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Udo H. Verkerk
- Department of Chemistry and Centre for Research in Mass Spectrometry, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
| | - Junfang Zhao
- Department of Chemistry and Centre for Research in Mass Spectrometry, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
| | - Michael J. Van Stipdonk
- Department of Chemistry, Wichita State University, Wichita, Kansas 67260-0051, United States
| | - Benjamin J. Bythell
- Computational Proteomics Group, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 580, 69120, Heidelberg, Germany
| | - Jos Oomens
- FOM Institute for Plasma Physics, 3430 BE Nieuwegein, The Netherlands
- University of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands
| | - Alan C. Hopkinson
- Department of Chemistry and Centre for Research in Mass Spectrometry, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
| | - K.W. Michael Siu
- Department of Chemistry and Centre for Research in Mass Spectrometry, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
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34
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Yu L, Tan Y, Tsai Y, Goodlett DR, Polfer NC. On the relevance of peptide sequence permutations in shotgun proteomics studies. J Proteome Res 2011; 10:2409-16. [PMID: 21413817 DOI: 10.1021/pr101235w] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In collision-induced dissociation (CID) of peptides, it has been observed that rearrangement processes can take place that appear to permute/scramble the original primary structure, which may in principle adversely affect peptide identification. Here, an analysis of sequence permutation in tandem mass spectra is presented for a previously published proteomics study on P. aeruginosa (Scherl et al., J. Am. Soc. Mass Spectrom.2008, 19, 891) conducted using an LTQ-orbitrap. Overall, 4878 precursor ions are matched by considering the accurate mass (i.e., <5 ppm) of the precursor ion and at least one fragment ion that confirms the sequence. The peptides are then grouped into higher- and lower-confidence data sets, using five fragment ions as a cutoff for higher-confidence identification. It is shown that the propensity for sequence permutation increases with the length of the tryptic peptide in both data sets. A higher charge state (i.e., 3+ vs 2+) also appears to correlate with a higher appearance of permuted masses for larger peptides. The ratio of these permuted sequence ions, compared to all tandem mass spectral peaks, reaches ∼25% in the higher-confidence data set, compared to an estimated incidence of false positives for permuted masses (maximum ∼8%), based on a null-hypothesis decoy data set.
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Affiliation(s)
- Long Yu
- Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611-7200, United States
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35
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Sztáray J, Memboeuf A, Drahos L, Vékey K. Leucine enkephalin--a mass spectrometry standard. MASS SPECTROMETRY REVIEWS 2011; 30:298-320. [PMID: 20669325 DOI: 10.1002/mas.20279] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Revised: 10/31/2009] [Accepted: 10/31/2009] [Indexed: 05/29/2023]
Abstract
The present article reviews the mass spectrometric fragmentation processes and fragmentation energetics of leucine enkephalin, a commonly used peptide, which has been studied in detail and has often been used as a standard or reference compound to test novel instrumentation, new methodologies, or to tune instruments. The main purpose of the article is to facilitate its use as a reference material; therefore, all available mass spectrometry-related information on leucine enkephalin has been critically reviewed and summarized. The fragmentation mechanism of leucine enkephalin is typical for a small peptide; but is understood far better than that of most other compounds. Because ion ratios in the MS/MS spectra indicate the degree of excitation, leucine enkephalin is often used as a thermometer molecule in electrospray or matrix-assisted laser desorption ionization (ESI or MALDI). Other parameters described for leucine enkephalin include collisional cross-section and energy transfer; proton affinity and gas-phase basicity; radiative cooling rate; and vibrational frequencies. The lowest-energy fragmentation channel of leucine enkephalin is the MH(+) → b(4) process. All available data for this process have been re-evaluated. It was found that, although the published E(a) values were significantly different, the corresponding Gibbs free energy change showed good agreement (1.32 ± 0.07 eV) in various studies. Temperature- and energy-dependent rate constants were re-evaluated with an Arrhenius plot. The plot showed good linear correlation among all data (R(2) = 0.97), spanned over a 9 orders of magnitude range in the rate constants and yielded 1.14 eV activation energy and 10(11.0) sec(-1) pre-exponential factor. Accuracy (including random and systematic errors, with a 95% confidence interval) is ±0.05 eV and 10(±0.5) sec(-1), respectively. The activation entropy at 470 K that corresponds to this reaction is -38.1 ± 9.6 J mol(-1) K(-1). We believe that these re-evaluated values are by far the most accurate activation parameters available at present for a protonated peptide and can be considered as "consensus" values; results on other processes might be compared to this reference value.
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Affiliation(s)
- Judit Sztáray
- Institute of Structural Chemistry, Chemical Research Center Hungarian Academy of Sciences, 1025 Budapest, Pusztaszeri ut 59-67, Hungary
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36
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Li X, Huang Y, O’Connor PB, Lin C. Structural heterogeneity of doubly-charged peptide b-ions. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2011; 22:245-54. [PMID: 21472584 PMCID: PMC3305756 DOI: 10.1007/s13361-010-0036-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 11/09/2010] [Accepted: 11/11/2010] [Indexed: 05/30/2023]
Abstract
Performing collisionally activated dissociation (CAD) and electron capture dissociation (ECD) in tandem has shown great promise in providing comprehensive sequence information that was otherwise unobtainable by using either fragmentation method alone or in duet. However, the general applicability of this MS(3) approach in peptide sequencing may be undermined by the formation of non-direct sequence ions, as sometimes observed under CAD, particularly when multiple stages of CAD are involved. In this study, varied-sized doubly-charged b-ions from three tachykinin peptides were investigated by ECD. Sequence scrambling was observed in ECD of all b-ions from neurokinin A (HKTDSFVGLM-NH(2)), suggesting the presence of N- and C-termini linked macro-cyclic conformers. On the contrary, none of the b-ions from eledoisin (pEPSKDAFIGLM-NH(2)) produced non-direct sequence ions under ECD, as it does not contain a free N-terminal amino group. ECD of several b-ions from Substance P (RPKPQQFFGLM-NH(2)) showed series of c(m)-Lys fragment ions which suggested that the macro-cyclic structure may also be formed by connecting the C-terminal carbonyl group and the ε-amino group of the lysine side chain. Theoretical investigation of selected Substance P b-ions revealed several low energy conformers, including both linear oxazolones and macro-ring structures, in corroboration with the experimental observation. This study showed that a b-ion may exist as a mixture of several forms, with their propensities influenced by its N-terminus, length, and certain side-chain groups. Further, the presence of several macro-cyclic structures may result in erroneous sequence assignment when the combined CAD and ECD methods are used in peptide sequencing.
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Affiliation(s)
- Xiaojuan Li
- Mass Spectrometry Resource, Department of Biochemistry, School of Medicine, Boston University, Boston, MA, USA
| | - Yiqun Huang
- Mass Spectrometry Resource, Department of Biochemistry, School of Medicine, Boston University, Boston, MA, USA
| | - Peter B. O’Connor
- Mass Spectrometry Resource, Department of Biochemistry, School of Medicine, Boston University, Boston, MA, USA
- Department of Chemistry, the University of Warwick, Coventry, UK
| | - Cheng Lin
- Mass Spectrometry Resource, Department of Biochemistry, School of Medicine, Boston University, Boston, MA, USA
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37
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Bari S, Gonzalez-Magaña O, Reitsma G, Werner J, Schippers S, Hoekstra R, Schlathölter T. Photodissociation of protonated leucine-enkephalin in the VUV range of 8–40 eV. J Chem Phys 2011; 134:024314. [DOI: 10.1063/1.3515301] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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38
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Atik AE, Yalcin T. A systematic study of acidic peptides for b-type sequence scrambling. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2011; 22:38-48. [PMID: 21472542 DOI: 10.1007/s13361-010-0018-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 10/08/2010] [Accepted: 10/09/2010] [Indexed: 05/30/2023]
Abstract
A systematic study was carried out to examine the effects of acidic amino acid residues and the position of the acidic group on the cyclization of b ions. The study utilized the model C-terminal amidated peptides XAAAAAA, AXAAAAA, AAXAAAA, AAAXAAA, AAAAXAA, AAAAAXA, AAAAAAX, XXAAAAAA, AAXXAAAA, AAAAXXAA, and AAAAAAXX, where X is a glutamic acid (E) or aspartic acid (D) residue. The CID mass spectra of b (n) (where n=7 and 8) ions derived from XAAAAAA, AAAXAAA, AAAAAAX and XXAAAAAA, AAXXAAAA, AAAAXXAA, and AAAAAAXX exhibited very similar fragmentation patterns for both the glutamic and the aspartic acid peptide series. The CID mass spectra of MH(+) derived from model peptides presented substantial direct and non-direct sequence b ions. The results indicate that b ions produced from acidic peptides can also undergo head-to-tail cyclization, which is the reason for the formation of the non-direct sequence b ions. The b ion spectra derived from the peptides became more complex as the number of acidic residues in the peptides increased. Side chains of glutamic and aspartic acid did not inhibit the cyclization of the b ions. Substantial water elimination was observed in all CID spectra of b (7) and b (8) ions. Finally, the preferential cleavage of glutamic or aspartic acid residues from macrocyclic structures of b ions was also investigated under various collision energy conditions.
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Affiliation(s)
- A Emin Atik
- Department of Chemistry, Faculty of Science, Izmir Institute of Technology, 35430 Urla-Izmir, Turkey
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39
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Saminathan IS, Wang XS, Guo Y, Krakovska O, Voisin S, Hopkinson AC, Siu KWM. The extent and effects of peptide sequence scrambling via formation of macrocyclic B ions in model proteins. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2010; 21:2085-2094. [PMID: 20947370 DOI: 10.1016/j.jasms.2010.09.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2010] [Revised: 08/18/2010] [Accepted: 09/01/2010] [Indexed: 05/30/2023]
Abstract
The extent and effects of sequence scrambling in peptide ions during tandem mass spectrometry (MS/MS) have been examined using tryptic peptides from model proteins. Sequence-scrambled b ions appeared in about 35% of 43 tryptic peptides examined under MS/MS conditions. In general, these ions had relatively low abundances with averages of 8% and 16%, depending on the instrumentation used. A few tryptic peptides gave abundant scrambled b ions in MS/MS. However, peptide and protein identifications under proteomic conditions with Mascot were not affected, even for these peptides wherein scrambling was prominent. From the 43 tryptic peptides that have been investigated, the conclusion is that sequence scrambling is unlikely to impact negatively on the accuracy of automated peptide and protein identifications in proteomics.
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Affiliation(s)
- Irine S Saminathan
- Department of Chemistry and Centre for Research in Mass Spectrometry, York University, Toronto, Ontario, Canada
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40
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Bythell BJ, Maître P, Paizs B. Cyclization and Rearrangement Reactions of an Fragment Ions of Protonated Peptides. J Am Chem Soc 2010; 132:14766-79. [DOI: 10.1021/ja101556g] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Benjamin J. Bythell
- Computational Proteomics Group, German Cancer Research Center, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany, and Laboratoire de Chimie Physique, Université Paris-Sud 11, UMR8000 CNRS, Faculté des Sciences, Bât. 350, 91405 Orsay Cedex, France
| | - Philippe Maître
- Computational Proteomics Group, German Cancer Research Center, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany, and Laboratoire de Chimie Physique, Université Paris-Sud 11, UMR8000 CNRS, Faculté des Sciences, Bât. 350, 91405 Orsay Cedex, France
| | - Béla Paizs
- Computational Proteomics Group, German Cancer Research Center, Im Neuenheimer Feld 580, 69120 Heidelberg, Germany, and Laboratoire de Chimie Physique, Université Paris-Sud 11, UMR8000 CNRS, Faculté des Sciences, Bât. 350, 91405 Orsay Cedex, France
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41
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Li Q, Zubieta JK, Kennedy RT. Practical aspects of in vivo detection of neuropeptides by microdialysis coupled off-line to capillary LC with multistage MS. Anal Chem 2010; 81:2242-50. [PMID: 19196160 DOI: 10.1021/ac802391b] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A method using capillary liquid chromatography-triple-stage mass spectrometry (LC-MS(3)) to determine endogenous opioid peptides in microdialysis samples collected in vivo was developed, validated, and applied to measurements in the rat striatum. Peptides in dialysate rapidly degraded when stored at room temperature or -80 degrees C. Adding acetic acid to a final concentration of 5% stabilized the peptides for 5 days allowing storage of fractions and off-line measurements which proved more convenient and reliable than previously used on-line methods. Study of the effect of dialysis flow rate from 0.2 to 2 microL/min and column inner diameter (i.d.) from 25 to 75 microm on the relative signal obtained for peptides revealed that lowest flow rates and smallest column i.d. gave the highest relative signal. The method was tested for 10 different neuropeptides and limits of detection (LODs) were from 0.5 to 60 pM (4 microL samples) for most. beta-Endorphin had an LOD of 5 nM when detected directly, but it could be quantitatively determined by detecting a characteristic peptide produced by tryptic digestion with an LOD of 3 pM. This approach may prove useful for other large neuropeptides as well. The method was used to determine met-enkephalin, leu-enkephalin, dynorphin A(1-8), and beta-endorphin in vivo. Endomorphin 1 and 2 were below the detection limit of the method in vivo. Quantitative determination of leu-enkephalin using external calibration was verified by standard addition experiments. The improvements over previous approaches using capillary LC-MS(n) make in vivo neuropeptide monitoring more practical and feasible for a variety of neuropeptides.
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Affiliation(s)
- Qiang Li
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, USA
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42
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Chen X, Steill JD, Oomens J, Polfer NC. Oxazolone versus macrocycle structures for Leu-enkephalin b2-b4: insights from infrared multiple-photon dissociation spectroscopy and gas-phase hydrogen/deuterium exchange. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2010; 21:1313-1321. [PMID: 20236836 DOI: 10.1016/j.jasms.2010.02.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Revised: 02/11/2010] [Accepted: 02/11/2010] [Indexed: 05/28/2023]
Abstract
The collision-induced dissociation (CID) products b(2)-b(4) from Leu-enkephalin are examined with infrared multiple-photon dissociation (IR-MPD) spectroscopy and gas-phase hydrogen/deuterium exchange (HDX). Infrared spectroscopy reveals that b(2) exclusively adopts oxazolone structures, protonated at the N-terminus and at the oxazolone ring N, based on the presence and absence of diagnostic infrared vibrations. This is correlated with the presence of a single HDX rate. For the larger b(3) and b(4), the IR-MPD measurements display diagnostic bands compatible with a mixture of oxazolone and macrocycle structures. This result is supported by HDX experiments, which show a bimodal distribution in the HDX spectra and two distinct rates in the HDX kinetic fitting. The kinetic fitting of the HDX data is employed to derive the relative abundances of macrocycle and oxazolone structures for b(3) and b(4), using a procedure recently implemented by our group for a series of oligoglycine b fragments (Chen et al. J. Am. Chem. Soc.2009, 131(51), 18272-18282. doi: 10.1021/ja9030837). In analogy to that study, the results suggest that the relative abundance of the macrocycle structure increases as a function of b fragment size, going from 0% for b(2) to approximately 6% for b(3), and culminating in 31% for b(4). Nonetheless, there are also surprising differences between both studies, both in the exchange kinetics and the propensity in forming macrocycle structures. This indicates that the chemistry of "head-to-tail" cyclization depends on subtle differences in the sequence as well as the size of the b fragment.
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Affiliation(s)
- Xian Chen
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA
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Demireva M, Williams ER. Measuring internal energy deposition in collisional activation using hydrated ion nanocalorimetry to obtain peptide dissociation energies and entropies. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2010; 21:1133-1143. [PMID: 20363645 DOI: 10.1016/j.jasms.2010.02.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 02/18/2010] [Accepted: 02/19/2010] [Indexed: 05/29/2023]
Abstract
The internal energy deposited in both on- and off-resonance collisional activation in Fourier transform ion cyclotron resonance mass spectrometry is measured with ion nanocalorimetry and is used to obtain information about the dissociation energy and entropy of a protonated peptide. Activation of Na(+)(H(2)O)(30) results in sequential loss of water molecules, and the internal energy of the activated ion can be obtained from the abundances of the product ions. Information about internal energy deposition in on-resonance collisional activation of protonated peptides is inferred from dissociation data obtained under identical conditions for hydrated ions that have similar m/z and degrees-of-freedom. From experimental internal energy deposition curves and Rice-Ramsperger-Kassel-Marcus (RRKM) theory, dissociation data as a function of collision energy for protonated leucine enkephalin, which has a comparable m/z and degrees-of-freedom as Na(+)(H(2)O)(30), are modeled. The threshold dissociation energies and entropies are correlated for data acquired at a single time point, resulting in a relatively wide range of threshold dissociation energies (1.1 to 1.7 eV) that can fit these data. However, this range of values could be significantly reduced by fitting data acquired at different dissociation times. By measuring the internal energy of an activated ion, the number of fitting parameters necessary to obtain information about the dissociation parameters by modeling these data is reduced and could result in improved accuracy for such methods.
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Affiliation(s)
- Maria Demireva
- Department of Chemistry, University of California-Berkeley, Berkeley, California 94720-1460, USA
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Samgina TY, Gorshkov VA, Artemenko KA, Kovalev SV, Ogourtsov SV, Zubarev RA, Lebedev AT. Novel natural peptides from Hyla arborea schelkownikowi skin secretion. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2010; 24:1749-1754. [PMID: 20499319 DOI: 10.1002/rcm.4571] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Hyla arborea schelkownikowi is one of the leaf frog species inhabiting the southern territories of Russia and the former USSR. This frog species is a member of the Hylidae Rafinesque, 1815 batrachians family. The present study deals with the previously uninvestigated peptidome of the Hyla arborea schelkownikowi skin secretion. Nano-electrospray ionization Fourier transform mass spectrometry (nanoESI-FTMS) of the skin secretion, in the intact form and after acetylation, was selected as the general method of analysis. Electron-capture dissociation (ECD) and collision-induced dissociation (CID) fragmentation were both employed, while de novo sequencing was performed by manual interpretation of the MS data. The suppression of the cyclization of b-ions in the mass spectrometer by the acetylation reaction proved to be very efficient for the de novo sequencing of short peptides. Ten skin peptides were found and all of them, except for bradykinin, had not previously been reported. Six of the peptides belong to the tryptophyllins and related peptides, while three peptides are similar to the aureins.
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Affiliation(s)
- T Yu Samgina
- Organic Chemistry Department, Moscow State University, Leninskie gory 1/3, GSP-1, MSU, Moscow 119991, Russian Federation
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Casal E, Lebrón-Aguilar R, Moreno FJ, Corzo N, Quintanilla-López JE. Selective linkage detection of O-sialoglycan isomers by negative electrospray ionization ion trap tandem mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2010; 24:885-893. [PMID: 20196190 DOI: 10.1002/rcm.4463] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Sialylated O-linked oligosaccharides are involved in many biological processes, such as cell-cell interactions, cell-substance adhesion, and virus-host interactions. These activities depend on their structure, which is frequently determined by tandem mass spectrometry. However, these spectra are frequently analyzer-dependent, which makes it difficult to develop widely applicable analytical methods. In order to deepen the origin of this behavior, two couples of isomers of sialylated O-linked oligosaccharides, NeuAc alpha2-3Gal beta1-3GalNAc-ol/Gal beta1-3(NeuAc alpha2-6)GalNAc-ol and NeuGc alpha2-3Gal beta1-3GalNAc-ol/Gal beta1-3(NeuGc alpha2-6)GalNAc-ol, were analyzed by liquid chromatography/negative electrospray ionization ion trap tandem mass spectrometry (LC/ESI(-)-MS(n)) using both an ion trap and a triple quadrupole mass spectrometer. Results clearly showed that while ions obtained in the triple quadrupole instrument fitted very well with the standard fragmentation routes, in the ion trap several intense ions could not be explained by these rules, specially a fragment at m/z 597. Furthermore, this ion was observed in the mass spectrum of those isomers that sialic acid binds to GalNAc by an alpha2-6 linkage. From the MS(3) spectrum of this ion an unexpected structure was deduced, and it led to propose alternative fragmentation pathways. Molecular mechanics calculations suggested that the found atypical route could be promoted by a hydrogen bond located only in alpha2-6-linked oligosaccharides. It has also been demonstrated that this process follows a slow kinetic, explaining why it cannot be observed using an ion beam-type mass analyzer. In conclusion, ion traps seem to be more appropriate than triple quadrupoles to develop a reliable analytical method to distinguish between isomeric O-linked glycans.
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Affiliation(s)
- Enriqueta Casal
- Instituto de Fermentaciones Industriales, CSIC, Madrid, Spain
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Zhang J, Chen Y, Zhang Z, Xing G, Wysocka J, Zhao Y. MS/MS/MS reveals false positive identification of histone serine methylation. J Proteome Res 2010; 9:585-94. [PMID: 19877717 DOI: 10.1021/pr900864s] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Methylation of lysine and arginine residues is known to play a key role in regulating histone structure and function. However, methylation of other amino acid residues in histones has not been previously described. Using exhaustive nano-HPLC/MS/MS and blind protein sequence database searches, we tentatively assigned methylation to serine 28 of histone H3 from calf thymus. The assignment was in agreement with our stringent manual verification rules, coelution in HPLC/MS/MS with its corresponding synthetic peptide, the dynamic nature of such methylation in distinct cell lines, and isotopic labeling. However, careful inspection of the MS/MS and MS/MS/MS spectra of a series of synthetic peptides confirmed that methylation actually occurs on K27 rather than on S28. The misassignment was caused by the fact that the (y(9) + 14) of the putative S28-methylated peptide and (b(9) + 18) ions of the K27 methylated peptide share the same m/z value (m/z 801). This MS/MS peak was used as the major evidence to assign methylation to S28 (consecutive y(8) and (y(9) + 14) ions). MS/MS/MS analysis revealed the false positive nature of serine methylation: the ambiguous ion at m/z 801 is indeed (b(9) + 18), an ion resulting from an in vitro reaction in the gas phase during collisionally activated dissociation (CAD). When lysine (K27) was acetylated, the degree of such in vitro reactions was greatly reduced, and such reactions were completely eliminated when the C-terminus was blocked by carboxylic group derivatization. Moreover, such side-chain assisted C-terminal rearrangement was found to be charge dependent. In aggregate, these results suggest that extra caution should be taken in interpretation of post-translational modification (PTM) data and that MS/MS as well as MS/MS/MS of synthetic peptides are needed for verifying the identity of peptides bearing a novel PTM.
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Affiliation(s)
- Junmei Zhang
- Protein Chemistry Technology Center, University of Texas Southwestern Medical Center at Dallas, Texas 75390-8816, USA
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Prussia AJ, Yang Y, Geballe MT, Snyder JP. Cyclostreptin and microtubules: is a low-affinity binding site required? Chembiochem 2010; 11:101-9. [PMID: 19946930 DOI: 10.1002/cbic.200900538] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cyclostreptin (CS) is a recently discovered natural product with cytotoxic activity caused by microtubule stabilization. It is the only known microtubule-stabilizing agent (MSA) that covalently binds to tubulin. It also exhibits the fast-binding kinetics seen for other MSAs. Through careful peptide digestion and mass spectrometry analysis, Buey et al. found that two amino acids are labeled by CS: Asn228, near the known taxane-binding site, and Thr220, in the type I microtubule pore. This led Buey et al. to propose Thr220 resides at the site previously predicted to be a way station or low-affinity site. By using molecular dynamics simulations and structural considerations of the microtubule pore and tubulin dimer, we conclude that postulation of a low-affinity site is unnecessary to explain the available experimental data. An alternative explanation views the microtubule pore as a structural entity that presents a substantial kinetic barrier to ligand passage to the known taxane-binding site-an entry point to the microtubule lumen that becomes completely blocked if cyclostreptin is bound at Thr220. Simulations of the free dimer also suggest a common mechanism of microtubule stabilization for taxane site MSAs through their conformational effect on the M-loop. Such an effect explains the low tubulin polymerization caused by cyclostreptin in vitro despite its covalent attachment.
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Affiliation(s)
- Andrew J Prussia
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, GA 30322, USA
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Chen X, Yu L, Steill JD, Oomens J, Polfer NC. Effect of peptide fragment size on the propensity of cyclization in collision-induced dissociation: oligoglycine b(2)-b(8). J Am Chem Soc 2010; 131:18272-82. [PMID: 19947633 DOI: 10.1021/ja9030837] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The chemistry of peptide fragmentation by collision-induced dissociation (CID) is currently being reviewed, as a result of observations that the amino acid sequence of peptide fragments can change upon activation. This rearrangement mechanism is thought to be due to a head-to-tail cyclization reaction, where the N-terminal and C-terminal part of the fragment are fused into a macrocycle (= cyclic peptide) structure, thus "losing" the memory of the original sequence. We present a comprehensive study for a series of b fragment ions, from b(2) to b(8), based on the simplest amino acid residue glycine, to investigate the effect of peptide chain length on the appearance of macrocycle fragment structures. The CID product ions are structurally characterized with a range of gas-phase techniques, including isotope labeling, infrared photodissociation spectroscopy, gas-phase hydrogen/deuterium exchange (using CH(3)OD), and computational structure approaches. The combined insights from these results yield compelling evidence that smaller b(n) fragments (n = 2, 3) exclusively adopt oxazolone-type structures, whereas a mixture of oxazolone and macrocycle b fragment structures are formed for midsized b(n) fragments, where n = 4-7. As each of these chemical structures exchanges at different rates, it is possible to approximate the relative abundances using kinetic fits to the H/D exchange data. Under the conditions used here, the "slow"-exchanging macrocycle structure represents approximately 30% of the b ion population for b(6)-b(7), while the "fast"-exchanging oxazolone structure represents the remainder (70%). Intriguingly, for b(8) only the macrocycle structure is identified, which is also consistent with the "slow" kinetic rate in the HDX results. In a control experiment, a protonated cyclic peptide with 6 amino acid residues, cyclo(Gln-Trp-Phe-Gly-Leu-Met), is confirmed not to adopt an oxazolone structure, even upon collisional activation. These results demonstrate that in some cases larger macrocycle structures are surprisingly stable. While more studies are required to establish the general propensity for cyclization in b fragments, the implications from this study are troubling in terms of faulty sequence identification.
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Affiliation(s)
- Xian Chen
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, USA
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Bari S, Hoekstra R, Schlathölter T. Peptide fragmentation by keV ion-induced dissociation. Phys Chem Chem Phys 2010; 12:3376-83. [DOI: 10.1039/b924145k] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Samgina TY, Kovalev SV, Gorshkov VA, Artemenko KA, Poljakov NB, Lebedev AT. N-terminal tagging strategy for de novo sequencing of short peptides by ESI-MS/MS and MALDI-MS/MS. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2010; 21:104-111. [PMID: 19836262 DOI: 10.1016/j.jasms.2009.09.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 09/11/2009] [Accepted: 09/11/2009] [Indexed: 05/28/2023]
Abstract
The major portion of skin secretory peptidome of the European Tree frog Hyla arborea consists of short peptides from tryptophyllin family. It is known that b-ions of these peptides undergo head-to-tail cyclization, forming a ring that can open, resulting in several linear forms. As a result, the spectrum contains multiple ion series, thus complicating de novo sequencing. This was observed in the Q-TOF spectrum of one of the tryptophyllins isolated from Hyla arborea; the sequence FLPFFP-NH(2) was established by Edman degradation and counter-synthesis. Though no rearrangements were observed in FTICR-MS and MALDI-TOF/TOF spectra, both of them were not suitable for mass-spectrometry sequencing due to the low sequence coverage. To obtain full amino acid sequence by mass spectrometry, three chemical modifications to N-terminal amino moiety were applied. They include acetylation and sulfobenzoylation of N-amino group and its transformation to 2,4,6-trimethylpyridinium by interaction with 2,4,6-trimethylpyrillium tetrafluoroborate. All three reagents block scrambling and provide spectra better than the intact peptide. Unfortunately, all of them also readily react with lysine side chain. Hence, all investigated procedures can be used to improve sequencing of short peptides, while acetylation is the recommended one. It shows excellent results, and it is plain and simple to perform. This is the procedure of choice for MS-sequencing of short peptides by manual or automatic algorithms.
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