1
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Mikawy NN, Rojas Ramírez C, DeFiglia SA, Szot CW, Le J, Lantz C, Wei B, Zenaidee MA, Blakney GT, Nesvizhskii AI, Loo JA, Ruotolo BT, Shabanowitz J, Anderson LC, Håkansson K. Are Internal Fragments Observable in Electron Based Top-Down Mass Spectrometry? Mol Cell Proteomics 2024:100814. [PMID: 39029587 DOI: 10.1016/j.mcpro.2024.100814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 06/26/2024] [Accepted: 07/12/2024] [Indexed: 07/21/2024] Open
Abstract
Protein tandem mass spectrometry (MS/MS) often generates sequence-informative fragments from backbone bond cleavages near the termini. This lack of fragmentation in the protein interior is particularly apparent in native top-down MS. Improved sequence coverage, critical for reliable annotation of posttranslational modifications (PTMs) and sequence variants, may be obtained from internal fragments generated by multiple backbone cleavage events. However, internal fragment assignments can be error prone due to isomeric/isobaric fragments from different parts of a protein sequence. Also, internal fragment generation propensity depends on the chosen MS/MS activation strategy. Here, we examine internal fragment formation in electron capture dissociation (ECD) and electron transfer dissociation (ETD) following native and denaturing MS, as well as liquid chromatography (LC)/MS of several proteins. Experiments were undertaken on multiple instruments, including Q-ToF, Orbitrap, and high-field FT-ICR across four laboratories. ECD was performed at both ultrahigh vacuum and at similar pressure to ETD conditions. Two complementary software packages were used for data analysis. When feasible, ETD-higher-energy collision dissociation (ETD-HCD) MS3 was performed to validate/refute potential internal fragment assignments, including differentiating MS3 fragmentation behavior of radical vs. even-electron primary fragments. We show that, under typical operating conditions, internal fragments cannot be confidently assigned in ECD, nor ETD. On the other hand, such fragments, along with some b-type terminal fragments (not typically observed in ECD/ETD spectra) appear at atypical ECD operating conditions, suggesting they originate from a separate ion-electron activation process. Furthermore, atypical fragment ion types, e.g., x ions, are observed at such conditions as well as upon EThcD, presumably due to vibrational activation of radical z-type ions.
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Affiliation(s)
- Neven N Mikawy
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, United States; Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Ain-Shams University, Cairo, Egypt
| | - Carolina Rojas Ramírez
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, United States; Department of Pathology, University of Michigan, Ann Arbor, MI 48109-5602, United States
| | - Steven A DeFiglia
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, United States
| | - Carson W Szot
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, United States
| | - Jessie Le
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, CA 90095, United States
| | - Carter Lantz
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, CA 90095, United States
| | - Benqian Wei
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, CA 90095, United States
| | - Muhammad A Zenaidee
- Australian Proteome Analysis Facility, Macquarie University, Sydney, NSW, 2109, Australia
| | - Greg T Blakney
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, United States
| | - Alexey I Nesvizhskii
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109-5602, United States; Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109-2218, United States
| | - Joseph A Loo
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, CA 90095, United States
| | - Brandon T Ruotolo
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, United States
| | - Jeffrey Shabanowitz
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, United States
| | - Lissa C Anderson
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, United States
| | - Kristina Håkansson
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, United States.
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2
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Youssef MM, Szot CW, Folz J, Collier LM, Kweon HK, DeFiglia SA, Ayad MF, Hussein LA, Abdel-Ghany MF, Hakansson K. Electron Capture vs Transfer Dissociation for Site Determination of Tryptic Peptide Tyrosine Sulfation: Direct Detection of Fibrinogen Sulfation Sites and Identification of Novel Isobaric Interferences. J Proteome Res 2024; 23:2386-2396. [PMID: 38900499 PMCID: PMC11231624 DOI: 10.1021/acs.jproteome.4c00072] [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] [Indexed: 06/21/2024]
Abstract
Tyrosine sulfation, an understudied but crucial post-translational modification, cannot be directly detected in conventional nanoflow liquid chromatography-tandem mass spectrometry (nanoLC-MS/MS) due to the extreme sulfate lability. Here, we report the detection of sulfate-retaining fragments from LC-electron capture dissociation (ECD) and nanoLC-electron transfer higher energy collision dissociation (EThcD). Sulfopeptide candidates were identified by Proteome Discoverer and MSFragger analysis of nanoLC-HCD MS/MS data and added to inclusion lists for LC-ECD or nanoLC-EThcD MS/MS. When this approach failed, targeted LC-ECD with fixed m/z isolation windows was performed. For the plasma protein fibrinogen, the known pyroglutamylated sulfopeptide QFPTDYDEGQDDRPK from the beta chain N-terminus was identified despite a complete lack of sulfate-containing fragment ions. The peptide QVGVEHHVEIEYD from the gamma-B chain C-terminus was also identified as sulfated or phosphorylated. This sulfopeptide is not annotated in Uniprot but was previously reported. MSFragger further identified a cysteine-containing peptide from the middle of the gamma chain as sulfated and deamidated. NanoLC-EThcD and LC-ECD MS/MS confirmed the two former sulfopeptides via sulfate-retaining fragment ions, whereas an unexpected fragmentation pattern was observed for the third sulfopeptide candidate. Manual interpretation of the LC-ECD spectrum revealed two additional isobaric identifications: a trisulfide-linked cysteinyl-glycine or a carbamidomethyl-dithiothreiotol covalent adduct. Synthesis of such adducts confirmed the latter identity.
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Affiliation(s)
- Menatallah M Youssef
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt
| | - Carson W Szot
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Jeff Folz
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Luke M Collier
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Hye Kyong Kweon
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Steven A DeFiglia
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Miriam F Ayad
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt
| | - Lobna A Hussein
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt
| | - Maha F Abdel-Ghany
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt
| | - Kristina Hakansson
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
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3
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Agostini M, Traldi P, Hamdan M. Mass Spectrometry Investigation of Some ATP-Binding Cassette (ABC) Proteins. MEDICINA (KAUNAS, LITHUANIA) 2024; 60:200. [PMID: 38399488 PMCID: PMC10890348 DOI: 10.3390/medicina60020200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/16/2024] [Accepted: 01/19/2024] [Indexed: 02/25/2024]
Abstract
Drug resistance remains one of the main causes of poor outcome in cancer therapy. It is also becoming evident that drug resistance to both chemotherapy and to antibiotics is driven by more than one mechanism. So far, there are at least eight recognized mechanisms behind such resistance. In this review, we choose to discuss one of these mechanisms, which is known to be partially driven by a class of transmembrane proteins known as ATP-binding cassette (ABC) transporters. In normal tissues, ABC transporters protect the cells from the toxic effects of xenobiotics, whereas in tumor cells, they reduce the intracellular concentrations of anticancer drugs, which ultimately leads to the emergence of multidrug resistance (MDR). A deeper understanding of the structures and the biology of these proteins is central to current efforts to circumvent resistance to both chemotherapy, targeted therapy, and antibiotics. Understanding the biology and the function of these proteins requires detailed structural and conformational information for this class of membrane proteins. For many years, such structural information has been mainly provided by X-ray crystallography and cryo-electron microscopy. More recently, mass spectrometry-based methods assumed an important role in the area of structural and conformational characterization of this class of proteins. The contribution of this technique to structural biology has been enhanced by its combination with liquid chromatography and ion mobility, as well as more refined labelling protocols and the use of more efficient fragmentation methods, which allow the detection and localization of labile post-translational modifications. In this review, we discuss the contribution of mass spectrometry to efforts to characterize some members of the ATP-binding cassette (ABC) proteins and why such a contribution is relevant to efforts to clarify the link between the overexpression of these proteins and the most widespread mechanism of chemoresistance.
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Affiliation(s)
| | - Pietro Traldi
- Corso Stati Uniti 4, Istituto di Ricerca Pediatrica Città della Speranza, 35100 Padova, Italy; (M.A.)
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4
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Miller SA, Jeanne Dit Fouque K, Hard ER, Balana AT, Kaplan D, Voinov VG, Ridgeway ME, Park MA, Anderson GA, Pratt MR, Fernandez-Lima F. Top/Middle-Down Characterization of α-Synuclein Glycoforms. Anal Chem 2023; 95:18039-18045. [PMID: 38047498 PMCID: PMC10836061 DOI: 10.1021/acs.analchem.3c02405] [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: 12/05/2023]
Abstract
α-Synuclein is an intrinsically disordered protein that plays a critical role in the pathogenesis of neurodegenerative disorders, such as Parkinson's disease. Proteomics studies of human brain samples have associated the modification of the O-linked N-acetyl-glucosamine (O-GlcNAc) to several synucleinopathies; in particular, the position of the O-GlcNAc can regulate protein aggregation and subsequent cell toxicity. There is a need for site specific O-GlcNAc α-synuclein screening tools to direct better therapeutic strategies. In the present work, for the first time, the potential of fast, high-resolution trapped ion mobility spectrometry (TIMS) preseparation in tandem with mass spectrometry assisted by an electromagnetostatic (EMS) cell, capable of electron capture dissociation (ECD), and ultraviolet photodissociation (213 nm UVPD) is illustrated for the characterization of α-synuclein positional glycoforms: T72, T75, T81, and S87 modified with a single O-GlcNAc. Top-down 213 nm UVPD and ECD MS/MS experiments of the intact proteoforms showed specific product ions for each α-synuclein glycoforms associated with the O-GlcNAc position with a sequence coverage of ∼68 and ∼82%, respectively. TIMS-MS profiles of α-synuclein and the four glycoforms exhibited large structural heterogeneity and signature patterns across the 8+-15+ charge state distribution; however, while the α-synuclein positional glycoforms showed signature mobility profiles, they were only partially separated in the mobility domain. Moreover, a middle-down approach based on the Val40-Phe94 (55 residues) chymotrypsin proteolytic product using tandem TIMS-q-ECD-TOF MS/MS permitted the separation of the parent positional isomeric glycoforms. The ECD fragmentation of the ion mobility and m/z separated isomeric Val40-Phe94 proteolytic peptides with single O-GlcNAc in the T72, T75, T81, and S87 positions provided the O-GlcNAc confirmation and positional assignment with a sequence coverage of ∼80%. This method enables the high-throughput screening of positional glycoforms and further enhances the structural mass spectrometry toolbox with fast, high-resolution mobility separations and 213 nm UVPD and ECD fragmentation capabilities.
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Affiliation(s)
- Samuel A Miller
- Department of Chemistry and Biochemistry and Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199, United States
| | - Kevin Jeanne Dit Fouque
- Department of Chemistry and Biochemistry and Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199, United States
| | - Eldon R Hard
- Department of Chemistry and Biological Sciences, University of Southern California, Los Angeles, California 90007, United States
| | - Aaron T Balana
- Department of Chemistry and Biological Sciences, University of Southern California, Los Angeles, California 90007, United States
| | - Desmond Kaplan
- KapScience LLC, Tewksbury, Massachusetts 01876, United States
| | | | - Mark E Ridgeway
- Bruker Daltonics Inc., Billerica, Massachusetts 01821, United States
| | - Melvin A Park
- Bruker Daltonics Inc., Billerica, Massachusetts 01821, United States
| | | | - Matthew R Pratt
- Department of Chemistry and Biological Sciences, University of Southern California, Los Angeles, California 90007, United States
| | - Francisco Fernandez-Lima
- Department of Chemistry and Biochemistry and Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199, United States
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5
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Berthias F, Thurman HA, Wijegunawardena G, Wu H, Shvartsburg AA, Jensen ON. Top-Down Ion Mobility Separations of Isomeric Proteoforms. Anal Chem 2023; 95:784-791. [PMID: 36562749 DOI: 10.1021/acs.analchem.2c02948] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Continuing advances in proteomics highlight the ubiquity and biological importance of proteoforms─proteins with varied sequence, splicing, or distribution of post-translational modifications (PTMs). The preeminent example is histones, where the PTM pattern encodes the combinatorial language controlling the DNA transcription central to life. While the proteoforms with distinct PTM compositions are distinguishable by mass, the isomers with permuted PTMs commonly coexisting in cells generally require separation before mass-spectrometric (MS) analyses. That was accomplished on the bottom-up and middle-down levels using chromatography or ion mobility spectrometry (IMS), but proteolytic digestion obliterates the crucial PTM connectivity information. Here, we demonstrate baseline IMS resolution of intact isomeric proteoforms, specifically the acetylated H4 histones (11.3 kDa). The proteoforms with a single acetyl moiety on five alternative lysine residues (K5, K8, K12, K16, K20) known for distinct functionalities in vivo were constructed by two-step native chemical ligation and separated using trapped IMS at the resolving power up to 350 on the Bruker TIMS/ToF platform. Full resolution for several pairs was confirmed using binary mixtures and by unique fragments in tandem MS employing collision-induced dissociation. This novel capability for top-down proteoform characterization is poised to open major new avenues in proteomics and epigenetics.
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Affiliation(s)
- Francis Berthias
- Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, DK-5230Odense M, Denmark
| | - Hayden A Thurman
- Department of Chemistry and Biochemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas67260, United States
| | - Gayani Wijegunawardena
- Department of Chemistry and Biochemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas67260, United States
| | - Haifan Wu
- Department of Chemistry and Biochemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas67260, United States
| | - Alexandre A Shvartsburg
- Department of Chemistry and Biochemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas67260, United States
| | - Ole N Jensen
- Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, DK-5230Odense M, Denmark
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6
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Fouque KJD, Miller SA, Pham K, Bhanu NV, Cintron-Diaz YL, Leyva D, Kaplan D, Voinov VG, Ridgeway ME, Park MA, Garcia BA, Fernandez-Lima F. Top-"Double-Down" Mass Spectrometry of Histone H4 Proteoforms: Tandem Ultraviolet-Photon and Mobility/Mass-Selected Electron Capture Dissociations. Anal Chem 2022; 94:15377-15385. [PMID: 36282112 PMCID: PMC11037235 DOI: 10.1021/acs.analchem.2c03147] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Post-translational modifications (PTMs) on intact histones play a major role in regulating chromatin dynamics and influence biological processes such as DNA transcription, replication, and repair. The nature and position of each histone PTM is crucial to decipher how this information is translated into biological response. In the present work, the potential of a novel tandem top-"double-down" approach─ultraviolet photodissociation followed by mobility and mass-selected electron capture dissociation and mass spectrometry (UVPD-TIMS-q-ECD-ToF MS/MS)─is illustrated for the characterization of HeLa derived intact histone H4 proteoforms. The comparison between q-ECD-ToF MS/MS spectra and traditional Fourier-transform-ion cyclotron resonance-ECD MS/MS spectra of a H4 standard showed a similar sequence coverage (∼75%) with significant faster data acquisition in the ToF MS/MS platform (∼3 vs ∼15 min). Multiple mass shifts (e.g., 14 and 42 Da) were observed for the HeLa derived H4 proteoforms for which the top-down UVPD and ECD fragmentation analysis were consistent in detecting the presence of acetylated PTMs at the N-terminus and Lys5, Lys8, Lys12, and Lys16 residues, as well as methylated, dimethylated, and trimethylated PTMs at the Lys20 residue with a high sequence coverage (∼90%). The presented top-down results are in good agreement with bottom-up TIMS ToF MS/MS experiments and allowed for additional description of PTMs at the N-terminus. The integration of a 213 nm UV laser in the present platform allowed for UVPD events prior to the ion mobility-mass precursor separation for collision-induced dissociation (CID)/ECD-ToF MS. Selected c305+ UVPD fragments, from different H4 proteoforms (e.g., Ac + Me2, 2Ac + Me2 and 3Ac + Me2), exhibited multiple IMS bands for which similar CID/ECD fragmentation patterns per IMS band pointed toward the presence of conformers, adopting the same PTM distribution, with a clear assignment of the PTM localization for each of the c305+ UVPD fragment H4 proteoforms. These results were consistent with the biological "zip" model, where acetylation proceeds in the Lys16 to Lys5 direction. This novel platform further enhances the structural toolbox with alternative fragmentation mechanisms (UVPD, CID, and ECD) in tandem with fast, high-resolution mobility separations and shows great promise for global proteoform analysis.
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Affiliation(s)
- Kevin Jeanne Dit Fouque
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
| | - Samuel A. Miller
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
| | - Khoa Pham
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
| | - Natarajan V. Bhanu
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, United States
| | - Yarixa L. Cintron-Diaz
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
| | - Dennys Leyva
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
| | | | | | | | - Melvin A. Park
- Bruker Daltonics Inc., Billerica, MA 01821, United States
| | - Benjamin A. Garcia
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, United States
| | - Francisco Fernandez-Lima
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
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7
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Miller SA, Fouque KJD, Ridgeway ME, Park MA, Fernandez-Lima F. Trapped Ion Mobility Spectrometry, Ultraviolet Photodissociation, and Time-of-Flight Mass Spectrometry for Gas-Phase Peptide Isobars/Isomers/Conformers Discrimination. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1267-1275. [PMID: 35658468 PMCID: PMC9262853 DOI: 10.1021/jasms.2c00091] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Trapped ion mobility spectrometry (TIMS) when coupled with mass spectrometry (MS) offers great advantages for the separation of isobaric, isomeric, and/or conformeric species. In the present work, we report the advantages of coupling TIMS with a low-cost, ultraviolet photodissociation (UVPD) linear ion trap operated at few mbars prior to time-of-flight (ToF) MS analysis for the effective characterization of isobaric, isomeric, and/or conformeric species based on mobility-selected fragmentation patterns. These three traditional challenges to MS-based separations are illustrated for the case of biologically relevant model systems: H3.1 histone tail PTM isobars (K4Me3/K18Ac), lanthipeptide regioisomers (overlapping/nonoverlapping ring patterns), and a model peptide conformer (angiotensin I). The sequential nature of the TIMS operation allows for effective synchronization with the ToF MS scans, in addition to parallel operation between the TIMS and the UVPD trap. Inspection of the mobility-selected UVPD MS spectra showed that for all three cases considered, unique fragmentation patterns (fingerprints) were observed per mobility band. Different from other IMS-UVPD implementations, the higher resolution of the TIMS device allowed for high mobility resolving power (R > 100) and effective mobility separation. The mobility selected UVPD MS provided high sequence coverage (>85%) with a fragmentation efficiency up to ∼40%.
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Affiliation(s)
- Samuel A. Miller
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
| | - Kevin Jeanne Dit Fouque
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
- Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, United States
| | | | - Melvin A. Park
- Bruker Daltonics Inc., Billerica, MA 01821, United States
| | - Francisco Fernandez-Lima
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
- Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, United States
- Corresponding Author: Francisco Fernandez-Lima,
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8
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Liu R, Xia S, Li H. Native top-down mass spectrometry for higher-order structural characterization of proteins and complexes. MASS SPECTROMETRY REVIEWS 2022:e21793. [PMID: 35757976 DOI: 10.1002/mas.21793] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Abstract
Progress in structural biology research has led to a high demand for powerful and yet complementary analytical tools for structural characterization of proteins and protein complexes. This demand has significantly increased interest in native mass spectrometry (nMS), particularly native top-down mass spectrometry (nTDMS) in the past decade. This review highlights recent advances in nTDMS for structural research of biological assemblies, with a particular focus on the extra multi-layers of information enabled by TDMS. We include a short introduction of sample preparation and ionization to nMS, tandem fragmentation techniques as well as mass analyzers and software/analysis pipelines used for nTDMS. We highlight unique structural information offered by nTDMS and examples of its broad range of applications in proteins, protein-ligand interactions (metal, cofactor/drug, DNA/RNA, and protein), therapeutic antibodies and antigen-antibody complexes, membrane proteins, macromolecular machineries (ribosome, nucleosome, proteosome, and viruses), to endogenous protein complexes. The challenges, potential, along with perspectives of nTDMS methods for the analysis of proteins and protein assemblies in recombinant and biological samples are discussed.
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Affiliation(s)
- Ruijie Liu
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Shujun Xia
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Huilin Li
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
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9
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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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10
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Edwards HM, Wu HT, Julian RR, Jackson GP. Differentiation of leucine and isoleucine residues in peptides using charge transfer dissociation mass spectrometry (CTD-MS). RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2022; 36:e9246. [PMID: 34927767 DOI: 10.1002/rcm.9246] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 06/14/2023]
Abstract
RATIONALE The function of a protein or the binding affinity of an antibody can be substantially altered by the replacement of leucine (Leu) with isoleucine (Ile), and vice versa, so the ability to identify the correct isomer using mass spectrometry can help resolve important biological questions. Tandem mass spectrometry approaches for Leu/Ile (Xle) discrimination have been developed, but they all have certain limitations. METHODS Four model peptides and two wild-type peptide sequences containing either Leu or Ile residues were subjected to charge transfer dissociation (CTD) mass spectrometry on a modified three-dimensional ion trap. The peptides were analyzed in both the 1+ and 2+ charge states, and the results were compared to conventional collision-induced dissociation spectra of the same peptides obtained using the same instrument. RESULTS CTD resulted in 100% sequence coverage for each of the studied peptides and provided a variety of side-chain cleavages, including d, w and v ions. Using CTD, reliable d and w ions of Xle residues were observed more than 80% of the time. When present, d ions are typically greater than 10% of the abundance of the corresponding a ions from which they derive, and w ions are typically more abundant than the z ions from which they derive. CONCLUSIONS CTD has the benefit of being applicable to both 1+ and 2+ precursor ions, and the overall performance is comparable to that of other high-energy activation techniques like hot electron capture dissociation and UV photodissociation. CTD does not require chemical modifications of the precursor peptides, nor does it require additional levels of isolation and fragmentation.
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Affiliation(s)
- Halle M Edwards
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, USA
| | - Hoi-Ting Wu
- Department of Chemistry, University of California, Riverside, CA, USA
| | - Ryan R Julian
- Department of Chemistry, University of California, Riverside, CA, USA
| | - Glen P Jackson
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, USA
- Department of Forensic and Investigative Science, West Virginia University, Morgantown, WV, USA
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11
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Shaw JB, Cooper-Shepherd DA, Hewitt D, Wildgoose JL, Beckman JS, Langridge JI, Voinov VG. Enhanced Top-Down Protein Characterization with Electron Capture Dissociation and Cyclic Ion Mobility Spectrometry. Anal Chem 2022; 94:3888-3896. [PMID: 35188751 PMCID: PMC8908312 DOI: 10.1021/acs.analchem.1c04870] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Tandem mass spectrometry of denatured, multiply charged high mass protein precursor ions yield extremely dense spectra with hundreds of broad and overlapping product ion isotopic distributions of differing charge states that yield an elevated baseline of unresolved "noise" centered about the precursor ion. Development of mass analyzers and signal processing methods to increase mass resolving power and manipulation of precursor and product ion charge through solution additives or ion-ion reactions have been thoroughly explored as solutions to spectral congestion. Here, we demonstrate the utility of electron capture dissociation (ECD) coupled with high-resolution cyclic ion mobility spectrometry (cIMS) to greatly increase top-down protein characterization capabilities. Congestion of protein ECD spectra was reduced using cIMS of the ECD product ions and "mobility fractions", that is, extracted mass spectra for segments of the 2D mobiligram (m/z versus drift time). For small proteins, such as ubiquitin (8.6 kDa), where mass resolving power was not the limiting factor for characterization, pre-IMS ECD and mobility fractions did not significantly increase protein sequence coverage, but an increase in the number of identified product ions was observed. However, a dramatic increase in performance, measured by protein sequence coverage, was observed for larger and more highly charged species, such as the +35 charge state of carbonic anhydrase (29 kDa). Pre-IMS ECD combined with mobility fractions yielded a 135% increase in the number of annotated isotope clusters and a 75% increase in unique product ions compared to processing without using the IMS dimension. These results yielded 89% sequence coverage for carbonic anhydrase.
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Affiliation(s)
- Jared B. Shaw
- e-MSion
Inc., 2121 NE Jack London Street, Corvallis, Oregon 97330, United States, (J.S.)
| | | | - Darren Hewitt
- Waters
Corporation, Wilmslow, Cheshire SK9 4AX, U.K.
| | | | - Joseph S. Beckman
- e-MSion
Inc., 2121 NE Jack London Street, Corvallis, Oregon 97330, United States,Linus
Pauling Institute and the Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, United States
| | | | - Valery G. Voinov
- e-MSion
Inc., 2121 NE Jack London Street, Corvallis, Oregon 97330, United States
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12
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Jeanne Dit Fouque K, Wellmann M, Leyva Bombuse D, Santos-Fernandez M, Cintron-Diaz YL, Gomez-Hernandez ME, Kaplan D, Voinov VG, Fernandez-Lima F. Effective discrimination of gas-phase peptide conformers using TIMS-ECD-ToF MS/MS. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2021; 13:5216-5223. [PMID: 34698320 PMCID: PMC8596503 DOI: 10.1039/d1ay01461g] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In the present work, four, well-studied, model peptides (e.g., substance P, bradykinin, angiotensin I and AT-Hook 3) were used to correlate structural information provided by ion mobility and ECD/CID fragmentation in a TIMS-q-EMS-ToF MS/MS platform, incorporporating an electromagnetostatic cell (EMS). The structural heterogeneity of the model peptides was observed by (i) multi-component ion mobility profiles (high ion mobility resolving power, R ∼115-145), and (ii) fast online characteristic ECD fragmentation patterns per ion mobility band (∼0.2 min). Particularly, it was demonstrated that all investigated species were probably conformers, involving cis/trans-isomerizations at X-Pro peptide bond, following the same protonation schemes, in good agreement with previous ion mobility and single point mutation experiments. The comparison between ion mobility selected ECD spectra and traditional FT-ICR ECD MS/MS spectra showed comparable ECD fragmentation efficiencies but differences in the ratio of radical (˙)/prime (') fragment species (H˙ transfer), which were associated with the differences in detection time after the electron capture event. The analysis of model peptides using online TIMS-q-EMSToF MS/MS provided complementary structural information on the intramolecular interactions that stabilize the different gas-phase conformations to those obtained by ion mobility or ECD alone.
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Affiliation(s)
- K Jeanne Dit Fouque
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
- Biomolecular Science Institute, Florida International University, Miami, FL 33199, USA
| | - M Wellmann
- Institute of Physical Chemistry, Christian-Albrechts-University Kiel, Kiel 24098, Germany
| | - D Leyva Bombuse
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
| | - M Santos-Fernandez
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
| | - Y L Cintron-Diaz
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
| | - M E Gomez-Hernandez
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
| | - D Kaplan
- KapScience LLC, Tewksbury, MA 01876, USA
| | - V G Voinov
- e-MSion Inc., Corvallis, OR 97330, USA
- Linus Pauling Institute and Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
| | - F Fernandez-Lima
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
- Biomolecular Science Institute, Florida International University, Miami, FL 33199, USA
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13
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Jeanne Dit Fouque K, Kaplan D, Voinov VG, Holck FHV, Jensen ON, Fernandez-Lima F. Proteoform Differentiation using Tandem Trapped Ion Mobility, Electron Capture Dissociation, and ToF Mass Spectrometry. Anal Chem 2021; 93:9575-9582. [PMID: 34170114 DOI: 10.1021/acs.analchem.1c01735] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Comprehensive characterization of post-translationally modified histone proteoforms is challenging due to their high isobaric and isomeric content. Trapped ion mobility spectrometry (TIMS), implemented on a quadrupole/time-of-flight (Q-ToF) mass spectrometer, has shown great promise in discriminating isomeric complete histone tails. The absence of electron activated dissociation (ExD) in the current platform prevents the comprehensive characterization of unknown histone proteoforms. In the present work, we report for the first time the use of an electromagnetostatic (EMS) cell devised for nonergodic dissociation based on electron capture dissociation (ECD), implemented within a nESI-TIMS-Q-ToF mass spectrometer for the characterization of acetylated (AcK18 and AcK27) and trimethylated (TriMetK4, TriMetK9 and TriMetK27) complete histone tails. The integration of the EMS cell in a TIMS-q-TOF MS permitted fast mobility-selected top-down ECD fragmentation with near 10% efficiency overall. The potential of this coupling was illustrated using isobaric (AcK18/TriMetK4) and isomeric (AcK18/AcK27 and TriMetK4/TriMetK9) binary H3 histone tail mixtures, and the H3.1 TriMetK27 histone tail structural diversity (e.g., three IMS bands at z = 7+). The binary isobaric and isomeric mixtures can be separated in the mobility domain with RIMS > 100 and the nonergodic ECD fragmentation permitted the PTM localization (sequence coverage of ∼86%). Differences in the ECD patterns per mobility band of the z = 7+ H3 TriMetK27 molecular ions suggested that the charge location is responsible for the structural differences observed in the mobility domain. This coupling further enhances the structural toolbox with fast, high resolution mobility separations in tandem with nonergodic fragmentation for effective proteoform differentiation.
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Affiliation(s)
- Kevin Jeanne Dit Fouque
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States.,Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199, United States
| | - Desmond Kaplan
- KapScience, LLC., Tewksbury, Massachusetts 01876, United States
| | - Valery G Voinov
- e-MSion, Inc., Corvallis, Oregon 97330, United States.,Linus Pauling Institute and Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, United States
| | - Frederik H V Holck
- Department of Biochemistry & Molecular Biology and VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Ole N Jensen
- Department of Biochemistry & Molecular Biology and VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Francisco Fernandez-Lima
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States.,Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199, United States
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14
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Shen X, Xu T, Hakkila B, Hare M, Wang Q, Wang Q, Beckman JS, Sun L. Capillary Zone Electrophoresis-Electron-Capture Collision-Induced Dissociation on a Quadrupole Time-of-Flight Mass Spectrometer for Top-Down Characterization of Intact Proteins. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:1361-1369. [PMID: 33749270 PMCID: PMC8576897 DOI: 10.1021/jasms.0c00484] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Mass spectrometry (MS)-based denaturing top-down proteomics (dTDP) requires high-capacity separation and extensive gas-phase fragmentation of proteoforms. Herein, we coupled capillary zone electrophoresis (CZE) to electron-capture collision-induced dissociation (ECciD) on an Agilent 6545 XT quadrupole time-of-flight (Q-TOF) mass spectrometer for dTDP for the first time. During ECciD, the protein ions were first fragmented using ECD, followed by further activation and fragmentation by applying a CID potential. In this pilot study, we optimized the CZE-ECciD method for small proteins (lower than 20 kDa) regarding the charge state of protein parent ions for fragmentation and the CID potential applied to maximize the protein backbone cleavage coverage and the number of sequence-informative fragment ions. The CZE-ECciD Q-TOF platform provided extensive backbone cleavage coverage for three standard proteins lower than 20 kDa from only single charge states in a single CZE-MS/MS run in the targeted MS/MS mode, including ubiquitin (97%, +7, 8.6 kDa), superoxide dismutase (SOD, 87%, +17, 16 kDa), and myoglobin (90%, +16, 17 kDa). The CZE-ECciD method produced comparable cleavage coverage of small proteins (i.e., myoglobin) with direct-infusion MS studies using electron transfer dissociation (ETD), activated ion-ETD, and combinations of ETD and collision-based fragmentation on high-end orbitrap mass spectrometers. The results render CZE-ECciD a new tool for dTDP to enhance both separation and gas-phase fragmentation of proteoforms.
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Affiliation(s)
- Xiaojing Shen
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, Michigan 48824, United States
| | - Tian Xu
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, Michigan 48824, United States
| | - Blake Hakkila
- e-MSion, Inc., 2121 NE Jack London Drive, Corvallis, Oregon 97330, United States
| | - Mike Hare
- e-MSion, Inc., 2121 NE Jack London Drive, Corvallis, Oregon 97330, United States
| | - Qianjie Wang
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, Michigan 48824, United States
| | - Qianyi Wang
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, Michigan 48824, United States
| | - Joseph S Beckman
- e-MSion, Inc., 2121 NE Jack London Drive, Corvallis, Oregon 97330, United States
- Linus Pauling Institute and the Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, United States
| | - Liangliang Sun
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, Michigan 48824, United States
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15
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Morgan TE, Kerr A, Wootton CA, Barrow MP, Bristow AW, Perrier S, O’Connor PB. Electron Capture Dissociation of Trithiocarbonate-Terminated Acrylamide Homo- and Copolymers: A Terminus-Directed Mechanism? Anal Chem 2020; 92:12852-12859. [DOI: 10.1021/acs.analchem.0c01224] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Tomos E. Morgan
- Department of Chemistry, University of Warwick, Coventry, Midlands CV4 7AL, U.K
| | - Andrew Kerr
- Department of Chemistry, University of Warwick, Coventry, Midlands CV4 7AL, U.K
| | | | - Mark P. Barrow
- Department of Chemistry, University of Warwick, Coventry, Midlands CV4 7AL, U.K
| | - Anthony W.T. Bristow
- Chemical Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Macclesfield, Cheshire SK10 2NA, U.K
| | - Sébastien Perrier
- Department of Chemistry, University of Warwick, Coventry, Midlands CV4 7AL, U.K
- Warwick Medical School, University of Warwick, Coventry CV4 7AL, U.K
- Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Peter B. O’Connor
- Department of Chemistry, University of Warwick, Coventry, Midlands CV4 7AL, U.K
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16
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Williams JP, Morrison LJ, Brown JM, Beckman JS, Voinov VG, Lermyte F. Top-Down Characterization of Denatured Proteins and Native Protein Complexes Using Electron Capture Dissociation Implemented within a Modified Ion Mobility-Mass Spectrometer. Anal Chem 2020; 92:3674-3681. [PMID: 31999103 DOI: 10.1021/acs.analchem.9b04763] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Electron-based fragmentation methods have revolutionized biomolecular mass spectrometry, in particular native and top-down protein analysis. Here, we report the use of a new electromagnetostatic cell to perform electron capture dissociation (ECD) within a quadrupole/ion mobility/time-of-flight mass spectrometer. This cell was installed between the ion mobility and time-of-flight regions of the instrument, and fragmentation was fast enough to be compatible with mobility separation. The instrument was already fitted with electron transfer dissociation (ETD) between the quadrupole and mobility regions prior to modification. We show excellent fragmentation efficiency for denatured peptides and proteins without the need to trap ions in the gas phase. Additionally, we demonstrate native top-down backbone fragmentation of noncovalent protein complexes, leading to comparable sequence coverage to what was achieved using the instrument's existing ETD capabilities. Limited collisional ion activation of the hemoglobin tetramer before ECD was reflected in the observed fragmentation pattern, and complementary ion mobility measurements prior to ECD provided orthogonal evidence of monomer unfolding within this complex. The approach demonstrated here provides a powerful platform for both top-down proteomics and mass spectrometry-based structural biology studies.
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Affiliation(s)
- Jonathan P Williams
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow SK9 4AX, United Kingdom
| | - Lindsay J Morrison
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow SK9 4AX, United Kingdom
| | - Jeffery M Brown
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow SK9 4AX, United Kingdom
| | - Joseph S Beckman
- e-MSion Inc., 2121 NE Jack London Drive, Corvallis, Oregon 97330, United States.,Linus Pauling Institute and the Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, United States
| | - Valery G Voinov
- e-MSion Inc., 2121 NE Jack London Drive, Corvallis, Oregon 97330, United States.,Linus Pauling Institute and the Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, United States
| | - Frederik Lermyte
- School of Engineering, University of Warwick, Coventry CV4 7AL, United Kingdom.,Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
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17
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Simmonds AL, Lopez-Clavijo AF, Winn PJ, Russell DH, Styles IB, Cooper HJ. Structural Analysis of 14-3-3-ζ-Derived Phosphopeptides Using Electron Capture Dissociation Mass Spectrometry, Traveling Wave Ion Mobility Spectrometry, and Molecular Modeling. J Phys Chem B 2020; 124:461-469. [PMID: 31859508 DOI: 10.1021/acs.jpcb.9b08506] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Previously, we have demonstrated the effect of salt bridges on the electron capture dissociation mass spectrometry behavior of synthetic model phosphopeptides and applied an ion mobility spectrometry/molecular modeling approach to rationalize the findings in terms of peptide ion structure. Here, we develop and apply the approach to a biologically derived phosphopeptide. Specifically, we have investigated variants of a 15-mer phosphopeptide VVGARRSsWRVVSSI (s denotes phosphorylated Ser) derived from Akt1 substrate 14-3-3-ζ, which contains the phosphorylation motif RRSsWR. Variants were generated by successive arginine-to-leucine substitutions within the phosphorylation motif. ECD fragmentation patterns for the eight phosphopeptide variants show greater sequence coverage with successive R → L substitutions. Peptides with two or more basic residues had regions with no sequence coverage, while full sequence coverage was observed for peptides with one or no basic residues. For three of the peptide variants, low-abundance fragments were observed between the phosphoserine and a basic residue, possibly due to the presence of multiple conformers with and without noncovalent interactions between these residues. For the five variants whose dissociation behavior suggested the presence of intramolecular noncovalent interactions, we employed ion mobility spectrometry and molecular modeling to probe the nature of these interactions. Our workflow allowed us to propose candidate structures whose noncovalent interactions were consistent with the ECD data for all of the peptides modeled. Additionally, the AMBER parameter sets created for and validated by this work are presented and made available online ( http://www.biosciences-labs.bham.ac.uk/cooper/datasets.php ).
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Affiliation(s)
| | | | | | - David H Russell
- Texas A&M University , College Station , Texas 77843 , United States
| | - Iain B Styles
- Centre of Membrane Proteins and Receptors (COMPARE) , Universities of Birmingham and Nottingham , Midlands , U.K
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18
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Affiliation(s)
| | | | - Jennifer S. Brodbelt
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
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19
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Lermyte F, Valkenborg D, Loo JA, Sobott F. Radical solutions: Principles and application of electron-based dissociation in mass spectrometry-based analysis of protein structure. MASS SPECTROMETRY REVIEWS 2018; 37:750-771. [PMID: 29425406 PMCID: PMC6131092 DOI: 10.1002/mas.21560] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 01/19/2018] [Accepted: 01/19/2018] [Indexed: 05/11/2023]
Abstract
In recent years, electron capture (ECD) and electron transfer dissociation (ETD) have emerged as two of the most useful methods in mass spectrometry-based protein analysis, evidenced by a considerable and growing body of literature. In large part, the interest in these methods is due to their ability to induce backbone fragmentation with very little disruption of noncovalent interactions which allows inference of information regarding higher order structure from the observed fragmentation behavior. Here, we review the evolution of electron-based dissociation methods, and pay particular attention to their application in "native" mass spectrometry, their mechanism, determinants of fragmentation behavior, and recent developments in available instrumentation. Although we focus on the two most widely used methods-ECD and ETD-we also discuss the use of other ion/electron, ion/ion, and ion/neutral fragmentation methods, useful for interrogation of a range of classes of biomolecules in positive- and negative-ion mode, and speculate about how this exciting field might evolve in the coming years.
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Affiliation(s)
- Frederik Lermyte
- Biomolecular and Analytical Mass Spectrometry Group, Department of Chemistry, University of Antwerp, Antwerp, Belgium
- Centre for Proteomics, University of Antwerp, Antwerp, Belgium
- School of Engineering, University of Warwick, Coventry, United Kingdom
| | - Dirk Valkenborg
- Centre for Proteomics, University of Antwerp, Antwerp, Belgium
- Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University, Agoralaan, Diepenbeek, Belgium
- Applied Bio and Molecular Systems, Flemish Institute for Technological Research (VITO), Mol, Belgium
| | - Joseph A Loo
- Department of Biological Chemistry, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California
- UCLA/DOE Institute for Genomics and Proteomics, University of California-Los Angeles, Los Angeles, California
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California
| | - Frank Sobott
- Biomolecular and Analytical Mass Spectrometry Group, Department of Chemistry, University of Antwerp, Antwerp, Belgium
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
- School of Molecular and Cellular Biology, University of Leeds, Leeds, United Kingdom
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20
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Shaw JB, Malhan N, Vasil'ev YV, Lopez NI, Makarov A, Beckman JS, Voinov VG. Sequencing Grade Tandem Mass Spectrometry for Top-Down Proteomics Using Hybrid Electron Capture Dissociation Methods in a Benchtop Orbitrap Mass Spectrometer. Anal Chem 2018; 90:10819-10827. [PMID: 30118589 DOI: 10.1021/acs.analchem.8b01901] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Compared to traditional collision induced dissociation methods, electron capture dissociation (ECD) provides more comprehensive characterization of large peptides and proteins as well as preserves labile post-translational modifications. However, ECD experiments are generally restricted to the high magnetic fields of FTICR-MS that enable the reaction of large polycations and electrons. Here, we demonstrate the use of an electromagnetostatic ECD cell to perform ECD and hybrid ECD methods utilizing 193 nm photons (ECuvPD) or collisional activation (EChcD) in a benchtop quadrupole-Orbitrap mass spectrometer. The electromagnetostatic ECD cell was designed to replace the transfer octapole between the quadrupole and C-trap. This implementation enabled facile installation of the ECD cell, and ions could be independently subjected to ECD, UVPD, HCD, or any combination. Initial benchmarking and characterization of fragmentation propensities for ECD, ECuvPD, and EChcD were performed using ubiquitin (8.6 kDa). ECD yielded extensive sequence coverage for low charge states of ubiquitin as well as for the larger protein carbonic anhydrase II (29 kDa), indicating pseudo-activated ion conditions. Additionally, relatively high numbers of d- and w-ions enable differentiation of isobaric isoleucine and leucine residues and suggest a distribution of electron energies yield hot-ECD type fragmentation. We report the most comprehensive characterization to date for model proteins up to 29 kDa and a monoclonal antibody at the subunit level. ECD, ECuvPD, and EChcD yielded 93, 95, and 91% sequence coverage, respectively, for carbonic anhydrase II (29 kDa), and targeted online analyses of monoclonal antibody subunits yielded 86% overall antibody sequence coverage.
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Affiliation(s)
- Jared B Shaw
- Environmental Molecular Sciences Laboratory , Pacific Northwest National Laboratory , 3335 Innovation Bouelvard , Richland , Washington 99354 , United States
| | - Neha Malhan
- Environmental Molecular Sciences Laboratory , Pacific Northwest National Laboratory , 3335 Innovation Bouelvard , Richland , Washington 99354 , United States
| | - Yury V Vasil'ev
- e-MSion Inc. , 2121 NE Jack London Drive , Corvallis , Oregon 97330 , United States.,Linus Pauling Institute and the Department of Biochemistry and Biophysics , Oregon State University , Corvallis , Oregon 97331 , United States
| | - Nathan I Lopez
- e-MSion Inc. , 2121 NE Jack London Drive , Corvallis , Oregon 97330 , United States.,Linus Pauling Institute and the Department of Biochemistry and Biophysics , Oregon State University , Corvallis , Oregon 97331 , United States
| | - Alexander Makarov
- Thermo Fisher Scientific (Bremen) GmbH , Hanna-Kunath Str. 11 , 28199 Bremen , Germany
| | - Joseph S Beckman
- e-MSion Inc. , 2121 NE Jack London Drive , Corvallis , Oregon 97330 , United States.,Linus Pauling Institute and the Department of Biochemistry and Biophysics , Oregon State University , Corvallis , Oregon 97331 , United States
| | - Valery G Voinov
- e-MSion Inc. , 2121 NE Jack London Drive , Corvallis , Oregon 97330 , United States.,Linus Pauling Institute and the Department of Biochemistry and Biophysics , Oregon State University , Corvallis , Oregon 97331 , United States
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21
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Fort KL, Cramer CN, Voinov VG, Vasil'ev YV, Lopez NI, Beckman JS, Heck AJR. Exploring ECD on a Benchtop Q Exactive Orbitrap Mass Spectrometer. J Proteome Res 2017; 17:926-933. [PMID: 29249155 PMCID: PMC5799867 DOI: 10.1021/acs.jproteome.7b00622] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
As the application of mass spectrometry intensifies in scope and diversity, the need for advanced instrumentation addressing a wide variety of analytical needs also increases. To this end, many modern, top-end mass spectrometers are designed or modified to include a wider range of fragmentation technologies, for example, ECD, ETD, EThcD, and UVPD. Still, the majority of instrument platforms are limited to more conventional methods, such as CID and HCD. While these latter methods have performed well, the less conventional fragmentation methods have been shown to lead to increased information in many applications including middle-down proteomics, top-down proteomics, glycoproteomics, and disulfide bond mapping. We describe the modification of the popular Q Exactive Orbitrap mass spectrometer to extend its fragmentation capabilities to include ECD. We show that this modification allows ≥85% matched ion intensity to originate from ECD fragment ion types as well as provides high sequence coverage (≥60%) of intact proteins and high fragment identification rates with ∼70% of ion signals matched. Finally, the ECD implementation promotes selective disulfide bond dissociation, facilitating the identification of disulfide-linked peptide conjugates. Collectively, this modification extends the capabilities of the Q Exactive Orbitrap mass spectrometer to a range of new applications.
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Affiliation(s)
- Kyle L Fort
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University , Utrecht 3584 CH, The Netherlands.,Netherlands Proteomics Center , Utrecht 3584 CH, The Netherlands
| | - Christian N Cramer
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University , Utrecht 3584 CH, The Netherlands.,Protein Engineering, Global Research Novo Nordisk A/S , Novo Nordisk Park, 2760 Måløv, Denmark.,Proteomics Program, The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen , 2200 Copenhagen, Denmark
| | - Valery G Voinov
- e-MSion, Inc. , 2121 NE Jack London Drive, Corvallis, Oregon 97330, United States.,Linus Pauling Institute, Department of Biochemistry and Biophysics, Oregon State University , Corvallis, Oregon 97331, United States
| | - Yury V Vasil'ev
- e-MSion, Inc. , 2121 NE Jack London Drive, Corvallis, Oregon 97330, United States.,Linus Pauling Institute, Department of Biochemistry and Biophysics, Oregon State University , Corvallis, Oregon 97331, United States
| | - Nathan I Lopez
- e-MSion, Inc. , 2121 NE Jack London Drive, Corvallis, Oregon 97330, United States
| | - Joseph S Beckman
- e-MSion, Inc. , 2121 NE Jack London Drive, Corvallis, Oregon 97330, United States.,Linus Pauling Institute, Department of Biochemistry and Biophysics, Oregon State University , Corvallis, Oregon 97331, United States
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University , Utrecht 3584 CH, The Netherlands.,Netherlands Proteomics Center , Utrecht 3584 CH, The Netherlands
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22
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Voinov VG, Hoffman PD, Bennett SE, Beckman JS, Barofsky DF. Electron Capture Dissociation of Sodium-Adducted Peptides on a Modified Quadrupole/Time-of-Flight Mass Spectrometer. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:2096-104. [PMID: 26266643 PMCID: PMC6726120 DOI: 10.1007/s13361-015-1230-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 07/13/2015] [Accepted: 07/14/2015] [Indexed: 05/02/2023]
Abstract
Electron capture dissociation (ECD), which generally preserves the position of labile post-translational modifications, can be a powerful method for de novo sequencing of proteins and peptides. In this report, ECD product-ion mass spectra of singly and doubly sodiated, nonphosphorylated, and phosphorylated peptides are presented and compared with the ECD mass spectra of their protonated counterparts. ECD of doubly charged, singly sodiated peptides yielded essentially the same sequence information as was produced by the corresponding doubly protonated peptides. The presence of several sodium binding sites on the polypeptide backbone, however, resulted in more complicated spectra. This situation is aggravated by the zwitterionic equilibrium of the free acid peptide precursors. The product-ion spectra of doubly and triply charged peptides possessing two sodium ions were further complicated by the existence of isomers created by the differential distribution of sodium binding sites. Triply charged, phosphorylated precursors containing one sodium, wherein the sodium is attached exclusively to the PO4 group, were found to be as useful for sequence analysis as the fully protonated species. Although sodium adducts are generally minimized during sample preparation, it appears that they can nonetheless provide useful sequence information. Additionally, they enable straightforward identification of a peptide's charge state, even on low-resolution instruments. The experiments were carried out using a radio frequency-free electromagnetostatic cell retrofitted into the collision-induced dissociation (CID) section of a hybrid quadrupole/time-of-flight tandem mass spectrometer. Graphical Abstract ᅟ.
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Affiliation(s)
- Valery G Voinov
- Department of Chemistry, Oregon State University, Corvallis, OR, 97331, USA.
- Pacific Institute of Bioorganic Chemistry, Vladivostok, Russia.
| | - Peter D Hoffman
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, 97331, USA
| | - Samuel E Bennett
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR, 97331, USA
| | - Joseph S Beckman
- Linus Pauling Institute, Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR, 97331, USA
| | - Douglas F Barofsky
- Department of Chemistry, Oregon State University, Corvallis, OR, 97331, USA
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23
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Voinov VG, Bennett SE, Barofsky DF. Electron-induced dissociation of peptides in a triple quadrupole mass spectrometer retrofitted with an electromagnetostatic cell. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:752-61. [PMID: 25652934 PMCID: PMC4446792 DOI: 10.1007/s13361-014-1074-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 12/18/2014] [Accepted: 12/19/2014] [Indexed: 05/02/2023]
Abstract
Dissociation of peptides induced by interaction with (free) electrons (electron-induced dissociation, EID) at electron energies ranging from near 0 to >30 eV was carried out using a radio-frequency-free electromagnetostatic (EMS) cell retrofitted into a triple quadrupole mass spectrometer. The product-ion mass spectra exhibited EID originating from electronically excited even-electron precursor ions, reduced radical cations formed by capture of low-energy electrons, and oxidized radical cations produced by interaction with high-energy electrons. The spectra demonstrate, within the limits of the triple quadrupole's resolving power, that high-energy EID product-ion spectra produced with an EMS cell exhibit essentially the same qualitative structural information, i.e., amino acid side-chain (SC) losses and backbone cleavages, as observed in high-energy EID spectra produced with a Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometer. The levels of fragmentation efficiency evident in the product-ion spectra recorded in this study, as was the case for those recorded in earlier studies with FT ICR mass spectrometers, is currently at the margin of analytical utility. Given that this shortcoming can be remedied, EMS cells incorporated into QqQ or QqTOF mass spectrometers could make tandem high-energy EID mass spectrometry more widely accessible for analysis of peptides, small singly charged molecules, pharmaceuticals, and clinical samples.
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Affiliation(s)
- Valery G Voinov
- Department of Chemistry, Oregon State University, Corvallis, OR, 97330, USA,
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24
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Voinov VG, Bennett SE, Beckman JS, Barofsky DF. ECD of tyrosine phosphorylation in a triple quadrupole mass spectrometer with a radio-frequency-free electromagnetostatic cell. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2014; 25:1730-8. [PMID: 25037842 PMCID: PMC4163116 DOI: 10.1007/s13361-014-0956-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 06/05/2014] [Accepted: 06/26/2014] [Indexed: 05/02/2023]
Abstract
A radio frequency-free electromagnetostatic (EMS) cell devised for electron-capture dissociation (ECD) of ions has been retrofitted into the collision-induced dissociation (CID) section of a triple quadrupole mass spectrometer to enable recording of ECD product-ion mass spectra and simultaneous recording of ECD-CID product-ion mass spectra. This modified instrument can be used to produce easily interpretable ECD and ECD-CID product-ion mass spectra of tyrosine-phosphorylated peptides that cover over 50% of their respective amino-acid sequences and readily identify their respective sites of phosphorylation. ECD fragmentation of doubly protonated, tyrosine-phosphorylated peptides, which was difficult to observe with FT-ICR instruments, occurs efficiently in the EMS cell.
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Affiliation(s)
- Valery G Voinov
- Department of Chemistry, Oregon State University, Corvallis, OR, 97333, USA,
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25
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Voinov VG, Deinzer ML, Beckman JS, Barofsky DF. Electron capture, collision-induced, and electron capture-collision induced dissociation in Q-TOF. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2011; 22:607-11. [PMID: 21472599 PMCID: PMC4285558 DOI: 10.1007/s13361-010-0072-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 12/22/2010] [Accepted: 12/27/2010] [Indexed: 05/02/2023]
Abstract
Recently, we demonstrated that a radio-frequency-free electromagnetostatic (rf-free EMS) cell could be retrofitted into a triple quad mass spectrometer to allow electron-capture dissociation (ECD) without the aid of cooling gas or phase-specific electron injection into the cell (Voinov et al., Rapid Commun Mass Spectrom 22, 3087-3088, 2008; Voinov et al., Anal Chem 81, 1238-1243, 2009). Subsequently, we used our rf-free EMS cell in the same instrument platform to demonstrate ECD occurring in the same space and at the same time with collision-induced dissociation (CID) to produce golden pairs and even triplets from peptides (Voinov et al., Rapid Commun Mass Spectrom 23, 3028-3030, 2009). In this report, we demonstrate that ECD and CID product-ion mass spectra can be recorded at high resolution with flexible control of fragmentation processes using a newly designed cell installed in a hybrid Q-TOF tandem mass spectrometer.
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Affiliation(s)
- Valery G Voinov
- Department of Chemistry, Oregon State University, Corvallis, OR 97331, USA.
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26
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Voinov VG, Beckman JS, Deinzer ML, Barofsky DF. Electron-capture dissociation (ECD), collision-induced dissociation (CID) and ECD/CID in a linear radio-frequency-free magnetic cell. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2009; 23:3028-30. [PMID: 19685479 PMCID: PMC3057201 DOI: 10.1002/rcm.4209] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Affiliation(s)
- Valery G. Voinov
- Department of Chemistry, Oregon State University, Corvallis, OR 97331, USA
- Pacific Institute of Bioorganic Chemistry, Vladivostok 690022, Russia
- Correspondence to: V. G. Voinov, Department of Chemistry, Oregon State University, Corvallis, OR 97331, USA.
| | - Joseph S. Beckman
- Department of Chemistry, Oregon State University, Corvallis, OR 97331, USA
| | - Max L. Deinzer
- Department of Chemistry, Oregon State University, Corvallis, OR 97331, USA
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27
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Hartmer RG, Kaplan DA, Stoermer C, Lubeck M, Park MA. Data-dependent electron transfer dissociation of large peptides and medium size proteins in a QTOF instrument on a liquid chromatography timescale. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2009; 23:2273-2282. [PMID: 19575399 DOI: 10.1002/rcm.4145] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Liquid chromatography (LC) electron transfer dissociation (ETD) tandem mass spectrometry (MS/MS) of protein digests is demonstrated in a hybrid quadrupole-hexapole orthogonal time-of-flight (OTOF) mass spectrometer. Analyte ions are selected in a mass-analyzing quadrupole, accumulated in the hexapole linear ETD reaction cell and mutually stored with ETD reagent anions. Product ions are collected in an ion cooler and then analyzed by an OTOF mass analyzer. The hexapole structure of the ETD reaction cell allows for a broad fragment ion mass range distribution and a high ion storage capacity. Analytically useful ETD OTOF-MS/MS spectra could be obtained at a rate of faster than 2 Hz. When used in conjunction with LC this high speed allows for several MS and MS/MS spectra to be obtained across each LC peak. An MS scan is used to select the precursor ions. With a 1 m flight tube and single reflection, resolutions of about 10 k and a mass accuracy of 5 ppm were achieved. When analyzing a 100 fmol solution of a tryptic digest of bovine serum albumin (BSA) by LC/ETD MS/MS, 27 unique peptides were identified with a summed Mascot score of 1316 using the Swiss Prot database. In addition, we explored the capability for analyzing small proteins with the present hybrid instrument. ETD MS/MS of intact ubiquitin ([M+12H](12+)) leads to the identification of the protein with a Mascot score of 264.
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Affiliation(s)
- Ralf G Hartmer
- Bruker Daltonik, GmbH, Fahrenheitstr. 4, D-28359 Bremen, Germany.
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28
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Voinov VG, Deinzer ML, Barofsky DF. Radio-frequency-free cell for electron capture dissociation in tandem mass spectrometry. Anal Chem 2009; 81:1238-43. [PMID: 19117494 DOI: 10.1021/ac802084w] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A radio frequency-free (RFF), analyzer-independent cell has been devised for electron-capture dissociation (ECD) of ions. The device is based on interleaving a series of electrostatic lenses with the periodic structure of magnetostatic lenses commonly found in a traveling wave tube. The RFF electrostatic/magnetostatic ECD cell was installed in a Finnigan TSQ700 ESI triple quadrupole (QqQ) spectrometer, and its performance was evaluated by recording product-ion spectra of doubly protonated substance P, doubly protonated gramicidin S, doubly protonated neurotensin, and triply protonated neurotensin. These spectra were readily obtained without recourse to a buffering gas or synchronizing electron injection with a specific phase of an RF field. The mass spectra produced with the modified instrument appear in all respects (other than resolution and mass accuracy, which were limited by the mass spectrometer used) to be at least as good for purposes of peptide identification as those recorded with Fourier transform ion cyclotron resonance (FT ICR) instruments; however, the effort and time to produce the mass spectra were much less than required to produce their FT ICR counterparts. The cell's design and compact construction should allow it to be incorporated at relatively little cost into virtually any type of tandem mass spectrometer, for example, triple quadrupole, hybrid quadrupole ion trap, hybrid quadrupole time-of-flight, or even FT-ICR.
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Affiliation(s)
- Valery G Voinov
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA.
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