1
|
Solovyeva EM, Kopysov VN, Pereverzev AY, Lobas AA, Moshkovskii SA, Gorshkov MV, Boyarkin OV. Method for Identification of Threonine Isoforms in Peptides by Ultraviolet Photofragmentation of Cold Ions. Anal Chem 2019; 91:6709-6715. [DOI: 10.1021/acs.analchem.9b00770] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Elizaveta M. Solovyeva
- Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, Station-6, 1015 Lausanne, Switzerland
- Moscow Institute of Physics and Technology (State University), 9 Institutskiy per., Dolgoprudny, Moscow Region, 141701, Russia
- V.L. Talrose Institute for Energy Problems of Chemical Physics, Russian Academy of Sciences, 38 Leninsky Pr., Bld.2 Moscow, 119334, Russia
| | - Vladimir N. Kopysov
- Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, Station-6, 1015 Lausanne, Switzerland
| | - Aleksandr Y. Pereverzev
- Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, Station-6, 1015 Lausanne, Switzerland
| | - Anna A. Lobas
- V.L. Talrose Institute for Energy Problems of Chemical Physics, Russian Academy of Sciences, 38 Leninsky Pr., Bld.2 Moscow, 119334, Russia
| | | | - Mikhail V. Gorshkov
- V.L. Talrose Institute for Energy Problems of Chemical Physics, Russian Academy of Sciences, 38 Leninsky Pr., Bld.2 Moscow, 119334, Russia
| | - Oleg V. Boyarkin
- Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, Station-6, 1015 Lausanne, Switzerland
| |
Collapse
|
2
|
Pereverzev AY, Kopysov VN, Boyarkin OV. Peptide Bond Ultraviolet Absorption Enables Vibrational Cold-Ion Spectroscopy of Nonaromatic Peptides. J Phys Chem Lett 2018; 9:5262-5266. [PMID: 30157636 DOI: 10.1021/acs.jpclett.8b02148] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Peptide-bond VUV absorption is inherent to all proteins and peptides. Although widely exploited in top-down proteomics for photodissociation, this absorption has never been spectroscopically characterized in the gas phase. We have measured VUV/UV photofragmentation spectrum of a single peptide bond in a cryogenically cold protonated dipeptide. Although the spectrum appears to be very broadband and structureless, vibrational pre-excitation of this and even larger cold peptides significantly increases the UV dissociation yield for some of their photofragments. We use this effect to extend the technique of IR-UV photofragmentation vibrational spectroscopy, developed for aromatic peptides, to nonaromatic ones and demonstrate measurements of conformation-specific and nonspecific IR spectra for di- to hexa-peptides.
Collapse
Affiliation(s)
- Aleksandr Y Pereverzev
- Laboratoire de Chimie Physique Moléculaire , École Polytechnique Fédérale de Lausanne , Station-6 , 1015 Lausanne , Switzerland
| | - Vladimir N Kopysov
- Laboratoire de Chimie Physique Moléculaire , École Polytechnique Fédérale de Lausanne , Station-6 , 1015 Lausanne , Switzerland
| | - Oleg V Boyarkin
- Laboratoire de Chimie Physique Moléculaire , École Polytechnique Fédérale de Lausanne , Station-6 , 1015 Lausanne , Switzerland
| |
Collapse
|
3
|
Talbert LE, Julian RR. Directed-Backbone Dissociation Following Bond-Specific Carbon-Sulfur UVPD at 213 nm. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:1760-1767. [PMID: 29623659 PMCID: PMC6087500 DOI: 10.1007/s13361-018-1934-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 02/16/2018] [Accepted: 02/23/2018] [Indexed: 05/22/2023]
Abstract
Ultraviolet photodissociation or UVPD is an increasingly popular option for tandem-mass spectrometry experiments. UVPD can be carried out at many wavelengths, and it is important to understand how the results will be impacted by this choice. Here, we explore the utility of 213 nm photons for initiating bond-selective fragmentation. It is found that bonds previously determined to be labile at 266 nm, including carbon-iodine and sulfur-sulfur bonds, can also be cleaved with high selectivity at 213 nm. In addition, many carbon-sulfur bonds that are not subject to direct dissociation at 266 nm can be selectively fragmented at 213 nm. This capability can be used to site-specifically create alaninyl radicals that direct backbone dissociation at the radical site, creating diagnostic d-ions. Furthermore, the additional carbon-sulfur bond fragmentation capability leads to signature triplets for fragmentation of disulfide bonds. Absorption of amide bonds can enhance dissociation of nearby labile carbon-sulfur bonds and can be used for stochastic backbone fragmentation typical of UVPD experiments at shorter wavelengths. Several potential applications of the bond-selective fragmentation chemistry observed at 213 nm are discussed. Graphical Abstract ᅟ.
Collapse
Affiliation(s)
- Lance E Talbert
- Department of Chemistry, University of California, Riverside, 501 Big Springs Road, Riverside, CA, 92521, USA
| | - Ryan R Julian
- Department of Chemistry, University of California, Riverside, 501 Big Springs Road, Riverside, CA, 92521, USA.
| |
Collapse
|
4
|
Warnke S, von Helden G, Pagel K. Analyzing the higher order structure of proteins with conformer-selective ultraviolet photodissociation. Proteomics 2015; 15:2804-12. [PMID: 25644066 DOI: 10.1002/pmic.201400480] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 12/19/2014] [Accepted: 01/28/2015] [Indexed: 11/09/2022]
Abstract
The top-down approach in protein sequencing requires simple methods in which the analyte can be readily dissociated at every position along the backbone. In this context, ultraviolet photodissociation (UVPD) recently emerged as a promising tool because, in contrast to slow heating techniques such as CID, the absorption of UV light is followed by a rather statistically distributed cleavage of backbone bonds. As a result, nearly complete sequence coverage can be obtained. It is well known, however, that gas-phase proteins can adopt a variety of different, sometimes coexisting conformations and the influence of this structural diversity on the UVPD fragmentation behavior is not clear. Using ion mobility-UVPD-MS, we recently showed that UVPD is sensitive to the higher order structure of gas-phase proteins. In particular, the cis/trans isomerization of certain proline peptide bonds was shown to significantly influence the UVPD fragmentation pattern of two extended conformers of 11(+) ubiquitin. Building on these results, we here provide conformer-selective UVPD data for 7(+) ubiquitin ions, which are known to be present in a much more diverse and wider ensemble of different structures, ranging from very compact to highly extended species. Our data show that certain conformers fall into groups with similar UVPD fragmentation pattern. Surprisingly, however, the conformers within each group can differ tremendously in their collision cross-section. This indicates that the multiple coexisting conformations typically observed for 7(+) ubiquitin are caused by a few, not easily interconvertible, subpopulations.
Collapse
Affiliation(s)
- Stephan Warnke
- Fritz Haber Institute of the Max Planck Society, Berlin, Germany
| | - Gert von Helden
- Fritz Haber Institute of the Max Planck Society, Berlin, Germany
| | - Kevin Pagel
- Fritz Haber Institute of the Max Planck Society, Berlin, Germany.,Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| |
Collapse
|
5
|
Moon JH, Yoon S, Bae YJ, Kim MS. Formation of gas-phase peptide ions and their dissociation in MALDI: insights from kinetic and ion yield studies. MASS SPECTROMETRY REVIEWS 2015; 34:94-115. [PMID: 24863621 DOI: 10.1002/mas.21427] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 03/17/2014] [Indexed: 06/03/2023]
Abstract
Insights on mechanisms for the generation of gas-phase peptide ions and their dissociation in matrix-assisted laser desorption ionization (MALDI) gained from the kinetic and ion yield studies are presented. Even though the time-resolved photodissociation technique was initially used to determine the dissociation kinetics of peptide ions and their effective temperature, it was replaced by a simpler method utilizing dissociation yields from in-source decay (ISD) and post-source decay (PSD). The ion yields for a matrix and a peptide were measured by repeatedly irradiating a region on a sample and collecting ion signals until the sample in the region was completely depleted. Matrix- and peptide-derived gas-phase cations were found to be generated by pre-formed ion emission or by ion-pair emission followed by anion loss, but not by laser-induced ionization. The total number of ions, that is, matrix plus peptide, was found to be equal to the number of ions emitted from a pure matrix. A matrix plume was found to cool as it expanded, from around 800-1,000 K to 400-500 K. Dissociation of peptide ions along b/y channels was found to occur statistically, that is, following RRKM behavior. Small critical energy (E0 = 0.6-0.7 eV) and highly negative critical entropy (ΔS(‡) = -30 to -25 eu) suggested that the transition structure was stabilized by multiple intramolecular interactions.
Collapse
Affiliation(s)
- Jeong Hee Moon
- Medical Proteomics Research Center, KRIBB, Daejeon, 305-806, Korea
| | | | | | | |
Collapse
|
6
|
Giuliani A, Milosavljević AR, Canon F, Nahon L. Contribution of synchrotron radiation to photoactivation studies of biomolecular ions in the gas phase. MASS SPECTROMETRY REVIEWS 2014; 33:424-441. [PMID: 24375654 DOI: 10.1002/mas.21398] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Photon activation of ions in the visible and ultraviolet range attracts a growing interest, partly for its promising applications in tandem mass spectrometry. However, this task is not trivial, as it requires notably high brilliance photon sources. Hence, most of the work in that field has been performed using lasers. Synchrotron radiation is a source continuously tunable over a wide photon energy range and which possesses the necessary characteristics for ion activation. This review focuses on the array of applications of synchrotron radiation in photon activation of ions ranging from near UV to soft X-rays.
Collapse
Affiliation(s)
- Alexandre Giuliani
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, 91192, Gif-sur-Yvette, France; UAR1008 CEPIA, INRA, 44316, Nantes, France
| | | | | | | |
Collapse
|
7
|
Warnke S, Baldauf C, Bowers MT, Pagel K, von Helden G. Photodissociation of Conformer-Selected Ubiquitin Ions Reveals Site-Specific Cis/Trans Isomerization of Proline Peptide Bonds. J Am Chem Soc 2014; 136:10308-14. [DOI: 10.1021/ja502994b] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Stephan Warnke
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Carsten Baldauf
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Michael T. Bowers
- Department
of Chemistry and Biochemistry, University of California, Santa Barbara, Santa
Barbara, California 93106, United States
| | - Kevin Pagel
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Gert von Helden
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| |
Collapse
|
8
|
Brodbelt JS. Photodissociation mass spectrometry: new tools for characterization of biological molecules. Chem Soc Rev 2014; 43:2757-83. [PMID: 24481009 PMCID: PMC3966968 DOI: 10.1039/c3cs60444f] [Citation(s) in RCA: 232] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Photodissociation mass spectrometry combines the ability to activate and fragment ions using photons with the sensitive detection of the resulting product ions by mass spectrometry. This combination affords a versatile tool for characterization of biological molecules. The scope and breadth of photodissociation mass spectrometry have increased substantially over the past decade as new research groups have entered the field and developed a number of innovative applications that illustrate the ability of photodissociation to produce rich fragmentation patterns, to cleave bonds selectively, and to target specific molecules based on incorporation of chromophores. This review focuses on many of the key developments in photodissociation mass spectrometry over the past decade with a particular emphasis on its applications to biological molecules.
Collapse
|
9
|
Kwon G, Kwon H, Lee J, Han SY, Moon B, Oh HB, Sung BJ. Density Functional Theory (DFT) Study of Gas-phase O.C Bond Dissociation Energy of Models for o-TEMPO-Bz-C(O)-Peptide: A Model Study for Free Radical Initiated Peptide Sequencing. B KOREAN CHEM SOC 2014. [DOI: 10.5012/bkcs.2014.35.3.770] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
10
|
Lai CK, Ng DCM, Pang HF, Le Blanc JCY, Hager JW, Fang DC, Cheung ASC, Chu IK. Laser-induced dissociation of singly protonated peptides at 193 and 266 nm within a hybrid linear ion trap mass spectrometer. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2013; 27:1119-27. [PMID: 23592116 DOI: 10.1002/rcm.6545] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 02/08/2013] [Accepted: 02/13/2013] [Indexed: 05/16/2023]
Abstract
RATIONALE We implemented, for the first time, laser-induced dissociation (LID) within a modified hybrid linear ion trap mass spectrometer, QTrap, while preserving the original scanning capabilities and routine performance of the instrument. METHODS Precursor ions of interest were mass-selected in the first quadrupole (Q1), trapped in the radiofrequency-only quadrupole (q2), photodissociated under irradiation with a 193- or 266-nm laser beam in the third quadrupole (q3), and mass-analyzed using the linear ion trap. RESULTS LID of singly charged protonated peptides revealed, in addition to conventional amide-bond cleavages, preferential fragmentation at Cα -C/N-Cα bonds of the backbone as well as at the Cα -Cβ /Cβ -Cγ bonds of the side-chains. The LID spectra of [M+H](+) featured product ions that were very similar to the observed radical-induced fragmentations in the CID spectra of analogous odd-electron radical cations generated through dissociative electron-transfer in metal-ligand-peptide complexes or through laser photolysis of iodopeptides. CONCLUSIONS LID of [M+H](+) ions results in fragmentation channels that are comparable with those observed upon the CID of M(•+) ions, with a range of fascinating radical-induced fragmentations.
Collapse
Affiliation(s)
- Cheuk-Kuen Lai
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | | | | | | | | | | | | | | |
Collapse
|
11
|
He Y, Webber N, Reilly JP. 157 nm photodissociation of a complete set of dipeptide ions containing C-terminal arginine. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2013; 24:675-683. [PMID: 23378257 DOI: 10.1007/s13361-012-0514-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 07/17/2012] [Accepted: 07/18/2012] [Indexed: 06/01/2023]
Abstract
Twenty singly-charged dipeptide ions with C-terminal arginine were photodissociated with 157 nm light and their tandem mass spectra recorded. Many of the small product ions that were observed are standard peptide fragments that have been commonly seen in VUV photodissociation studies. However, the study of a library of dipeptides containing all 20 N-terminal amino acids enabled the recognition of trends associated with the occurrence of w-, v-, and immonium ions, the observation of competition between forming N- and C-terminal fragments in dipeptide RR, and the identification of some unusual fragment ions appearing at masses of 183, 187, 196, and 197 Da. A highly accurate internal calibration of the photodissociation TOF-TOF data enabled molecular formulae for these four product ions to be derived. Their proposed structures reflect the rather high-energy nature of this fragmentation phenomenon.
Collapse
Affiliation(s)
- Yi He
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | | | | |
Collapse
|
12
|
He Y, Parthasarathi R, Raghavachari K, Reilly JP. Photodissociation of charge tagged peptides. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2012; 23:1182-1190. [PMID: 22532332 DOI: 10.1007/s13361-012-0379-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 02/29/2012] [Accepted: 03/16/2012] [Indexed: 05/31/2023]
Abstract
Tris(2,4,6-trimethoxyphenyl) phosphonium acetyl (TMPP-Ac) was previously introduced to improve the mass spectrometric sequence analysis of peptides by fixing a permanent charge at the N-termini. However, peptides containing arginine residues did not fragment efficiently after TMPP-Ac modification. In this work, we combine charge derivatization with photodissociation. The fragmentation of TMPP-derivatized peptides is greatly improved and a series of N-terminal fragments is generated with complete sequence information. Arginine has a special effect on the fragmentation of the TMPP tagged peptides when it is the N-terminal peptide residue. Theoretical and experimental results suggest that this is due to hydrogen transfer from the charged N-terminus to the hydrogen-deficient peptide sequence.
Collapse
Affiliation(s)
- Yi He
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | | | | | | |
Collapse
|
13
|
Madsen JA, Cheng RR, Kaoud TS, Dalby KN, Makarov DE, Brodbelt JS. Charge-site-dependent dissociation of hydrogen-rich radical peptide cations upon vacuum UV photoexcitation. Chemistry 2012; 18:5374-83. [PMID: 22431222 DOI: 10.1002/chem.201103534] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Indexed: 11/06/2022]
Abstract
Here, 193 nm vacuum ultraviolet photodissociation (VUVPD) was used to investigate the fragmentation of hydrogen-rich radical peptide cations generated by electron transfer reactions. VUVPD offers new insight into the factors that drive radical- and photon-directed processes. The location of a basic Arg site influences photon-activated C(α)-C(O) bond cleavages of singly charged peptide radical cations, an outcome attributed to the initial conformation of the peptide as supported by molecular dynamics simulated annealing and the population of excited states upon UV excitation. This hybrid ETD/VUVPD method was employed to identify phosphorylation sites of the kinase domain of human TRPM7/ChaK1.
Collapse
Affiliation(s)
- James A Madsen
- Department of Chemistry and Biochemistry, The University of Texas at Austin, 1 University Station A5300, Austin, TX 78712, USA
| | | | | | | | | | | |
Collapse
|
14
|
Kalli A, Grigorean G, Håkansson K. Electron induced dissociation of singly deprotonated peptides. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2011; 22:2209-2221. [PMID: 21952776 DOI: 10.1007/s13361-011-0233-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 08/11/2011] [Accepted: 08/12/2011] [Indexed: 05/31/2023]
Abstract
Dissociation of singly charged species is more challenging compared with that of multiply charged precursor ions because singly charged ions are generally more stable. In collision activated dissociation (CAD), singly charged ions also gain less kinetic energy in a fixed electric field compared with multiply charged species. Furthermore, ion-electron and ion-ion reactions that frequently provide complementary and more extensive fragmentation compared with CAD typically require multiply charged precursor ions. Here, we investigate electron induced dissociation (EID) of singly deprotonated peptides and compare the EID fragmentation patterns with those observed in negative ion mode CAD. Fragmentation induced upon electron irradiation and collisional activation is not specific and results in the formation of a wide range of product ions, including b-, y-, a-, x-, c-, and z-type ions. Characteristic amino acid side chain losses are detected in both techniques. However, differences are also observed between EID and CAD spectra of the same species, including formation of odd-electron species not seen in CAD, in EID. Furthermore, EID frequently results in more extensive fragmentation compared with CAD. For modified peptides, EID resulted in retention of sulfonation and phosphorylation, allowing localization of the modification site. The observed differences are likely due to both vibrational and electronic excitation in EID, whereas only the former process occurs in CAD.
Collapse
Affiliation(s)
- Anastasia Kalli
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI 48109-1055, USA
| | | | | |
Collapse
|
15
|
Lee M, Lee Y, Kang M, Park H, Seong Y, Sung BJ, Moon B, Oh HB. Disulfide bond cleavage in TEMPO-free radical initiated peptide sequencing mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2011; 46:830-839. [PMID: 21834022 DOI: 10.1002/jms.1955] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The gas-phase free radical initiated peptide sequencing (FRIPS) fragmentation behavior of o-TEMPO-Bz-conjugated peptides with an intra- and intermolecular disulfide bond was investigated using MS(n) tandem mass spectrometry experiments. Investigated peptides included four peptides with an intramolecular cyclic disulfide bond, Bactenecin (RLCRIVVIRVCR), TGF-α (CHSGYVGVRC), MCH (DFDMLRCMLGRVFRPCWQY) and Adrenomedullin (16-31) (CRFGTCTVQKLAHQIY), and two peptides with an intermolecular disulfide bond. Collisional activation of the benzyl radical conjugated peptide cation, which was generated through the release of a TEMPO radical from o-TEMPO-Bz-conjugated peptides upon initial collisional activation, produced a large number of peptide backbone fragments in which the S-S or C-S bond was readily cleaved. The observed peptide backbone fragments included a-, c-, x- or z-types, which indicates that the radical-driven peptide fragmentation mechanism plays an important role in TEMPO-FRIPS mass spectrometry. FRIPS application of the linearly linked disulfide peptides further showed that the S-S or C-S bond was selectively and preferentially cleaved, followed by peptide backbone dissociations. In the FRIPS mass spectra, the loss of •SH or •SSH was also abundantly found. On the basis of these findings, FRIPS fragmentation pathways for peptides with a disulfide bond are proposed. For the cleavage of the S-S bond, the abstraction of a hydrogen atom at C(β) by the benzyl radical is proposed to be the initial radical abstraction/transfer reaction. On the other hand, H-abstraction at C(α) is suggested to lead to C-S bond cleavage, which yields [ion ± S] fragments or the loss of •SH or •SSH.
Collapse
Affiliation(s)
- Minhee Lee
- Department of Chemistry, Sogang University, Seoul 121-742, Korea
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Shin YS, Moon JH, Kim MS. Selective screening of tyrosine-nitrated peptides in tryptic mixtures by in-source photodissociation at 355 nm in matrix-assisted laser desorption ionization. Anal Chem 2011; 83:1704-8. [PMID: 21309608 DOI: 10.1021/ac1028352] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nitration of tyrosine residues in proteins is an important post-translational modification related to various diseases such as Alzheimer's. In this work, efficient and selective photodissociation (PD) at 355 nm was observed for [M + H](+), [M + H - 16](+), and [M + H - 32](+) generated by matrix-assisted ultraviolet laser desorption ionization (UV-MALDI) of tyrosine-nitrated peptides (nitropeptides). Product ion spectra obtained by post-source PD at this wavelength contained useful information on the amino acid sequence. The spectra for nitropeptides obtained with 355 nm irradiation inside the ion source (MALDI/in-source PD) displayed characteristic triplet patterns due to PD of the above ions. For peptides displaying prominent signal in a MALDI mass map of a tryptic mixture, which are mostly those with arginine at the C-terminus, in-source PD allowed positive identification of their tyrosine-nitrated forms. Identification of such nitropeptides was possible at the 10 fmol level (in tryptic digest of 100 fmol BSA).
Collapse
Affiliation(s)
- Young Sik Shin
- Department of Chemistry, Seoul National University, Seoul, Korea
| | | | | |
Collapse
|
17
|
Ko BJ, Brodbelt JS. Ultraviolet photodissociation of carboxylate-derivatized peptides in a quadrupole ion trap. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2011; 22:49-56. [PMID: 21472543 DOI: 10.1007/s13361-010-0016-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Accepted: 10/13/2010] [Indexed: 05/30/2023]
Abstract
The fragmentation patterns obtained by ultraviolet photodissociation (UVPD) and collision-induced dissociation (CID) in a quadrupole ion trap mass spectrometer were compared for peptides modified at their C-termini and at acidic amino acids. Attachment of Alexa Fluor 350 or 7-amino-4-methyl-coumarin chromophores at the C-terminal and acidic residues enhances the UV absorptivity of the peptides and all fragment ions that retain the chromophore, such as the y ions that contain the chromophore-modified C-terminus. Whereas CID results in the formation of the typical array of mainly y-type and a/b-type fragment ions, UVPD produces predominantly a/b-type ions with greatly reduced abundances of y ions. Immonium ions, mostly ones from aromatic or basic amino acids, are also observed in the low m/z range upon UVPD. UVPD of peptides containing two chromophore moieties (with one at the C-terminus and another at an acidic residue) results in even more efficient photodissociation at the expense of the annihilation of almost all diagnostic b and y ions containing the chromophore.
Collapse
Affiliation(s)
- Byoung Joon Ko
- Department of Chemical Engineering, University of Texas at Austin, 1 University Station A5300, Austin, TX 78712, USA
| | | |
Collapse
|
18
|
Demeure K, Gabelica V, De Pauw EA. New advances in the understanding of the in-source decay fragmentation of peptides in MALDI-TOF-MS. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2010; 21:1906-1917. [PMID: 20832332 DOI: 10.1016/j.jasms.2010.07.009] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Revised: 07/23/2010] [Accepted: 07/28/2010] [Indexed: 05/29/2023]
Abstract
In-source decay (ISD) is a rapid fragmentation occurring in the matrix-assisted laser desorption/ionization (MALDI) source before the ion extraction. Despite the increasing interest for peptides de novo sequencing by ISD, the influence of the matrix and of the peptide itself is not yet fully understood. Here we compare matrices with high ISD efficiencies to gain deeper insight in the ISD fragmentation process(es). The major ISD fragments are the c- and z-ions, but other types of fragments are also observed, and their origin is studied here. Two main pathways lead to fragmentation in the source: a radical-induced pathway that leads to c-, z-, w-, and d-ions, and a thermally activated pathway that leads to y-, b-, and a-ions. A detailed analysis of the ISD spectra of selected peptides revealed that (1) the extents of the two in-source pathways are differently favored depending on the matrix used, that (2) the presence of a positive/negative charge on the radical-induced fragments is necessary for their observation in positive/negative mode, respectively, and that (3), for a same peptide, the patterns of the different types of fragments differ according to the matrix used.
Collapse
Affiliation(s)
- Kevin Demeure
- General and Physical Chemistry Department, Mass Spectrometry Laboratory, Liege University, Liege, Belgium
| | | | | |
Collapse
|
19
|
Yoon SH, Moon JH, Kim MS. Dissociation mechanisms and implication for the presence of multiple conformations for peptide ions with arginine at the C-terminus: time-resolved photodissociation study. JOURNAL OF MASS SPECTROMETRY : JMS 2010; 45:806-814. [PMID: 20564416 DOI: 10.1002/jms.1773] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Time-resolved photodissociation (PD) patterns of singly protonated peptides with arginine at the C-terminus (C-arg peptide ions) have been used to classify the dissociation channels into two categories, i.e. high-energy channels generating v, w and x and low-energy ones generating b, y and z. x + 1 formed by C(alpha)-CO cleavage seems to be the intermediate ion in high-energy channels just as a + 1 is for N-arg peptide ions. Difference in time-resolved pattern indicates that the two sets of channels, high- and low-energy ones, are not in direct competition. Noncompetitive dissociation is also indicated by the observation of anomalous effect of matrix used in matrix-assisted laser desorption ionization, a cooler matrix generating more high-energy product ions both in spontaneous dissociation and in PD. Results from detailed investigation suggest that the two sets of channels start from two (or more) different conformations.
Collapse
Affiliation(s)
- So Hee Yoon
- Department of Chemistry, Seoul National University, Seoul 151-742, Korea
| | | | | |
Collapse
|
20
|
Parthasarathi R, He Y, Reilly JP, Raghavachari K. New Insights into the Vacuum UV Photodissociation of Peptides. J Am Chem Soc 2010; 132:1606-10. [DOI: 10.1021/ja907975v] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Yi He
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405
| | - James P. Reilly
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405
| | | |
Collapse
|
21
|
Ly T, Julian R. Ultraviolet Photodissociation: Developments towards Applications for Mass-Spectrometry-Based Proteomics. Angew Chem Int Ed Engl 2009; 48:7130-7. [DOI: 10.1002/anie.200900613] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
22
|
Ly T, Julian R. Photodissoziation durch UV-Licht: Anwendungen in der massenspektrometrischen Proteomforschung. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200900613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
23
|
Cook SL, Collin OL, Jackson GP. Metastable atom-activated dissociation mass spectrometry: leucine/isoleucine differentiation and ring cleavage of proline residues. JOURNAL OF MASS SPECTROMETRY : JMS 2009; 44:1211-23. [PMID: 19466707 DOI: 10.1002/jms.1598] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Extensive backbone fragmentation resulting in a-, b-, c-, x-, y- and z-type ions is observed of singly and doubly charged peptide ions through their interaction with a high kinetic energy beam of argon or helium metastable atoms in a modified quadrupole ion trap mass spectrometer. The ability to determine phosphorylation-sites confirms the observation with previous reports and we report the new ability to distinguish between leucine and isoleucine residues and the ability to cleave two covalent bonds of the proline ring resulting in a-, b-, x-, y-, z- and w-type ions. The fragmentation spectra indicate that fragmentation occurs through nonergodic radical ion chemistry akin to electron capture dissociation (ECD), electron transfer dissociation (ETD) and electron ionization dissociation mechanisms. However, metastable atom-activated dissociation mass spectrometry demonstrates three apparent benefits to ECD and ETD: (1) the ability to fragment singly charged precursor ions, (2) the ability to fragment negatively charged ions and (3) the ability to cleave the proline ring that requires the cleavage of two covalent bonds. Helium metastable atoms generated more fragment ions than argon metastable atoms for both substance P and bradykinin regardless of the precursor ion charge state. Reaction times less than 250 ms and efficiencies approaching 5% are compatible with on-line fragmentation, as would be desirable for bottom-up proteomics applications.
Collapse
Affiliation(s)
- Shannon L Cook
- Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701-2979, USA
| | | | | |
Collapse
|
24
|
Yoon SH, Moon JH, Kim MS. Time-resolved photodissociation study of singly protonated peptides with a histidine residue generated by matrix-assisted laser desorption ionization: dissociation rate constant and internal temperature. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2009; 20:1522-1529. [PMID: 19467884 DOI: 10.1016/j.jasms.2009.04.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2009] [Revised: 04/11/2009] [Accepted: 04/14/2009] [Indexed: 05/27/2023]
Abstract
Product ion yields in post-source decay and time-resolved photodissociation at 193 and 266 nm were measured for some peptide ions with a histidine residue ([HF(6) + H](+), [F(6)H + H](+), and [F(3)HF(3) + H](+)) formed by matrix-assisted laser desorption ionization (MALDI). Compared with similar data for peptide ions without any basic residue reported previously, significant reduction in dissociation efficiency was observed. Internal temperatures (T) of the peptide ions and their dissociation kinetic parameters-the critical energy (E(0)) and entropy (DeltaS(double dagger))-were determined by the method reported previously. Slight decreases in E(0), DeltaS(double dagger), and T were responsible for the histidine effect-reduction in dissociation rate constant. Regardless of the presence of the residue, DeltaS(double dagger) was far more negative than previous quantum chemical results. Based on this, we propose the existence of transition structures in which the nitrogen atoms in the histidine residue or at the N-terminus coordinate to the reaction centers. Reduction in T in the presence of a histidine residue could not be explained based on popular models for ion formation in MALDI, such as the gas-phase proton transfer model.
Collapse
Affiliation(s)
- So Hee Yoon
- Department of Chemistry, Seoul National University, Seoul, Korea
| | | | | |
Collapse
|
25
|
Brodbelt JS, Wilson JJ. Infrared multiphoton dissociation in quadrupole ion traps. MASS SPECTROMETRY REVIEWS 2009; 28:390-424. [PMID: 19294735 DOI: 10.1002/mas.20216] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The development of new ion activation techniques continues to be a dynamic area of scientific discovery, in part to complement the tremendous innovations in ionization methods that have allowed the mass spectrometric analysis of an enormous array of molecules. Ion activation/dissociation provides key information about ion structures, binding energies, and differentiation of isomers, as well as affording a primary means of identifying compounds in mixtures. Numerous new activation methods have emerged over the past two decades in an effort to develop alternatives to collisional activated dissociation, the gold standard for providing structurally diagnostic fragmentation patterns. Collisional activated dissociation does not always offer sufficiently high or controllable energy deposition, thus rendering it less useful for certain classes of molecules, such as large proteins or macromolecular complexes. Photodissociation is one of the most promising alternatives and is readily implemented in ion trapping and time-of-flight mass spectrometers. Photodissociation generally entails using a laser to irradiate ions with UV, visible, or IR photons, thus resulting in internal energy deposition based on the number and wavelengths of the photons. The activation process can be extremely rapid and efficient, as well as having the potential for high total energy deposition. This review describes infrared multiphoton dissociation in quadrupole ion trap mass spectrometry. A comparison of photodissociation and collisional activated dissociation is covered, in addition to some of the methods to increase photodissociation efficiency. Numerous applications of IRMPD are discussed as well, including ones related to the analysis of drugs, peptides, nucleic acids, and oligosaccharides.
Collapse
Affiliation(s)
- Jennifer S Brodbelt
- Department of Chemistry and Biochemistry, University of Texas, Austin, TX 78712, USA.
| | | |
Collapse
|
26
|
Abstract
Mass spectrometric identification of all types of molecules relies on the observation and interpretation of ion fragmentation patterns. Peptides, proteins, carbohydrates, and nucleic acids that are often found as components of complex biological samples represent particularly important challenges. The most common strategies for fragmenting biomolecular ions include low- and high-energy collisional activation, post-source decay, and electron capture or transfer dissociation. Each of these methods has its own idiosyncrasies and advantages but encounters problems with some types of samples. Novel fragmentation methods that can offer improvements are always desirable. One approach that has been under study for years but is not yet incorporated into a commercial instrument is ultraviolet photofragmentation. This review discusses experimental results on various biological molecules that have been generated by several research groups using different light wavelengths and mass analyzers. Work involving short-wavelength vacuum ultraviolet light is particularly emphasized. The characteristics of photofragmentation are examined and its advantages summarized.
Collapse
Affiliation(s)
- James P Reilly
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| |
Collapse
|
27
|
Moon JH, Yoon SH, Kim MS. Temperature of Peptide Ions Generated by Matrix-Assisted Laser Desorption Ionization and Their Dissociation Kinetic Parameters. J Phys Chem B 2009; 113:2071-6. [DOI: 10.1021/jp810077e] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jeong Hee Moon
- Department of Chemistry, Seoul National University, Seoul 151-742, Korea, and Systemic Proteomics Research Center, KRIBB, Daejeon 305-806, Korea
| | - So Hee Yoon
- Department of Chemistry, Seoul National University, Seoul 151-742, Korea, and Systemic Proteomics Research Center, KRIBB, Daejeon 305-806, Korea
| | - Myung Soo Kim
- Department of Chemistry, Seoul National University, Seoul 151-742, Korea, and Systemic Proteomics Research Center, KRIBB, Daejeon 305-806, Korea
| |
Collapse
|
28
|
Antol I, Vazdar M, Barbatti M, Eckert-Maksić M. The effect of protonation on the photodissociation processes in formamide – An ab initio surface hopping dynamics study. Chem Phys 2008. [DOI: 10.1016/j.chemphys.2008.01.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
29
|
Yoon SH, Chung YJ, Kim MS. Time-resolved photodissociation of singly protonated peptides with an arginine at the N-terminus: a statistical interpretation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2008; 19:645-655. [PMID: 18356076 DOI: 10.1016/j.jasms.2008.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Revised: 02/14/2008] [Accepted: 02/16/2008] [Indexed: 05/26/2023]
Abstract
Time-evolution of product ion signals in ultraviolet photodissociation (UV-PD) of singly protonated peptides with an arginine at the N-terminus was investigated by using a tandem time-of-flight mass spectrometer equipped with a cell floated at high voltage. Observation of different time-evolution patterns for different product ion types--an apparently nonstatistical behavior--could be explained within the statistical framework by invoking consecutive formation of some product ions and broad internal energy distributions for precursor ions. a(n) + 1 and b(n) ions were taken as the primary product ions from this type of peptide ions. Spectral characteristics in post-source decay, UV-PD, and collisionally activated dissociation at low and high kinetic energies could be explained via rough statistical calculation of rate constants. Specifically, the striking characteristics in high-energy CAD and UV-PD--dominance of a(n) and d(n) formed via a(n) + 1--were not due to the peculiarity of the excitation processes themselves, but due to quenching of the b(n) channels caused by the presence of arginine.
Collapse
Affiliation(s)
- So Hee Yoon
- Department of Chemistry, Seoul National University, Seoul, Korea
| | | | | |
Collapse
|
30
|
Wilson JJ, Kirkovits GJ, Sessler JL, Brodbelt JS. Photodissociation of non-covalent peptide-crown ether complexes. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2008; 19:257-60. [PMID: 18077179 PMCID: PMC2288744 DOI: 10.1016/j.jasms.2007.10.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2007] [Revised: 10/29/2007] [Accepted: 10/29/2007] [Indexed: 05/25/2023]
Abstract
Highly chromogenic 18-crown-6-dipyrrolylquinoxaline coordinates primary amines of peptides, forming non-covalent complexes that can be transferred to the gas-phase by electrospray ionization. The appended chromogenic crown ether facilitates efficient energy transfer to the peptide upon ultraviolet irradiation in the gas phase, resulting in diagnostic peptide fragmentation. Collisional-activated dissociation and infrared multiphoton dissociation of these non-covalent complexes result only in their disassembly with the charge retained on either the peptide or crown ether, yielding no sequence ions. Upon UV photon absorption the intermolecular energy transfer is facilitated by the fast activation timescale of ultraviolet photodissociation (<10 ns) and by the collectively strong hydrogen bonding between the crown ether and peptide, thus allowing effective transfer of energy to the peptide moiety before disruption of the intermolecular hydrogen bonds.
Collapse
Affiliation(s)
- Jeffrey J Wilson
- Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712, USA
| | | | | | | |
Collapse
|
31
|
Yoon SH, Kim MS. Development of a time-resolved method for photodissociation mechanistic study of protonated peptides: use of a voltage-floated cell in a tandem time-of-flight mass spectrometer. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2007; 18:1729-39. [PMID: 17702598 DOI: 10.1016/j.jasms.2007.07.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 06/26/2007] [Accepted: 07/03/2007] [Indexed: 05/16/2023]
Abstract
Photodissociation at 266 nm of some protonated peptides was investigated using a tandem-TOF spectrometer equipped with a cell near its first time focal point where the laser was irradiated. When a high voltage was applied to the cell, each product ion peak split into several components with different flight times. One of these was due to in-cell direct formation of the product ion and another due to post-cell formation. Those in between were due to consecutive dissociations, the first steps of which occurred inside the cell and the second steps outside the cell. A method based on flight time calculation was developed to analyze these components and to identify the intermediate ion for each consecutive component. The technique allows time-resolved photodissociation mechanistic studies on a 100-ns timescale.
Collapse
Affiliation(s)
- So Hee Yoon
- Department of Chemistry, Seoul National University, Seoul, Korea
| | | |
Collapse
|
32
|
Wilson JJ, Brodbelt JS. MS/MS simplification by 355 nm ultraviolet photodissociation of chromophore-derivatized peptides in a quadrupole ion trap. Anal Chem 2007; 79:7883-92. [PMID: 17845006 DOI: 10.1021/ac071241t] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ultraviolet photodissociation (UVPD) of chromophore-modified peptides enhances the capabilities for de novo sequencing in a quadrupole ion trap mass spectrometer. Attachment of UV chromophores allows efficient photoactivation of not only the precursor ions but also any fragments that retain the chromophore functionality. For doubly protonated peptides, UVPD leads to a vast reduction in MS/MS complexity. The array of b and y ions typically seen upon collisionally activated dissociation is reduced to a single series of either y or b ions by UVPD depending on the location of the chromophore (i.e., N- or C-terminus). The sulfonation reagent Alexa Fluor 350 (AF350) provided the best overall results for the singly and doubly charged peptides by UVPD. The nonsulfonated analogue of AF350, 7-amino-4-methylcoumarin-3-acetic acid, also led to simplified spectra for doubly charged, but not singly charged, peptides by UVPD. Dinitrophenyl-peptides also yielded simplified spectra by UVPD albeit with a small amount of internal fragments accompanying the series of diagnostic y ions. The success of this MS/MS simplification process stems from extensive secondary fragmentation of any chromophore-containing fragments upon exposure to subsequent laser pulses. Energy-variable UVPD reveals that the abundances of non-chromophore-containing y fragment ions increase linearly with laser pulse energy, suggesting secondary dissociation of these species is insignificant. The abundances of chromophore-containing a/b fragment ions follow a quadratic trend due to the extensive secondary fragmentation at higher laser energies or multiple pulses.
Collapse
Affiliation(s)
- Jeffrey J Wilson
- Department of Chemistry and Biochemistry, University of Texas at Austin, 1 University Station A5300, Austin, Texas 78712, USA
| | | |
Collapse
|
33
|
Thompson MS, Cui W, Reilly JP. Factors that impact the vacuum ultraviolet photofragmentation of peptide ions. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2007; 18:1439-52. [PMID: 17543535 DOI: 10.1016/j.jasms.2007.04.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Revised: 04/20/2007] [Accepted: 04/24/2007] [Indexed: 05/15/2023]
Abstract
Several groups have investigated the photodissociation of peptide ions with ultraviolet light. Significant differences have been reported with 157 and 193 nm excitation. Recent studies have shown that the mass analyzer can also influence the observed photofragment distribution. Comparison of experiments using different peptides, wavelengths, and mass analyzers is undesirably complicated. In the present work, several peptides are analyzed with both 157 and 193 nm photodissociation in tandem-TOF and linear ion trap mass spectrometers. The results indicate that the fragment ion distribution can be influenced by both the photodissociation wavelength and the mass analyzer. The two wavelengths generate similar spectra in an ion trap but quite different results in a tandem-TOF instrument.
Collapse
Affiliation(s)
- Matthew S Thompson
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-4001, USA
| | | | | |
Collapse
|