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Wang Y, Lau JKC, Lai CK, Hopkinson AC, Siu KWM. Doubly Charged Small Organic Fragments Derived from [Ce(tripeptide)(CH 3CN) m] 3+ Complexes: Observation of the Elusive [b n + H] 2+ Ions. J Phys Chem B 2019; 123:10192-10201. [PMID: 31693371 DOI: 10.1021/acs.jpcb.9b09090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[a3 + H]2+ ions generated from Ln3+/tripeptide complexes, where Ln = La or Ce, have similar structures to the linear [an]+ ions but with protonation at both the terminal NH2 and N═CH2 groups. Ion stability is favored by having the basic secondary amine of the proline residue at the N-terminus and by an amino acid residue accommodating one of the protons on the side chain. Dissociation of [a3 + H]2+ ions derived from peptides containing only aliphatic residues is by cleavage of the second amide bond to give [b2]+ or [a2]+ ions along with internal [a1]+ ions. For [a3 + H]2+ ions containing a tryptophan residue in the central location, in addition to cleavage of the amide bond, losses of neutrals NH3, HN═CHR, (NH3 + CO), and HNCO were observed. Dissociations of some unsolvated Ln3+/tripeptide complexes gave [b3 + H]2+ ions in low abundance; formation of these [b3 + H]2+ ions was favored by the presence of a proline residue at the N-terminus and by either a histidine or tryptophan residue in the central position. Dissociation of these [b3 + H]2+ ions was by the loss of (H2O + CO) and not only CO, indicating that these ions did not have the same type of oxazolone structure as found for [bn]+ ions. Density functional theory calculations suggest that the observed [b3 + H]2+ ions of ProGlyGly were formed from [Ce(ProGlyGly)]3+ complexes in which the peptide was bound to the metal ion as an enolate. Dissociation of the slightly lower-energy complex, where the peptide is bound in the keto form, would produce an oxazolone but the high barrier required to create this isomer of the [b3 + H]2+ ion would be sufficient to result in further dissociation. Two isomers of the [b3 + H]2+ ion of ProHisGly have been created, one from the [Ce(ProHisGly)]3+ complex that characteristically dissociates by the combined loss of (H2O + CO) and the other by the loss of glycine from [ProHisGlyGly + 2H]2+. The [b3 + H]2+ ion derived from [ProHisGlyGly + 2H]2+ dissociated by the loss of only CO.
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Affiliation(s)
- Yating Wang
- Department of Chemistry and Centre for Research in Mass Spectrometry , York University , 4700 Keele Street , Toronto , ON M3J 1P3 , Canada
| | - Justin Kai-Chi Lau
- Department of Chemistry and Centre for Research in Mass Spectrometry , York University , 4700 Keele Street , Toronto , ON M3J 1P3 , Canada.,Department of Chemistry and Biochemistry , University of Windsor , 401 Sunset Avenue , Windsor , ON N9B 3P4 , Canada
| | - Cheuk-Kuen Lai
- Department of Chemistry and Centre for Research in Mass Spectrometry , York University , 4700 Keele Street , Toronto , ON M3J 1P3 , Canada
| | - Alan C Hopkinson
- Department of Chemistry and Centre for Research in Mass Spectrometry , York University , 4700 Keele Street , Toronto , ON M3J 1P3 , Canada
| | - K W Michael Siu
- Department of Chemistry and Centre for Research in Mass Spectrometry , York University , 4700 Keele Street , Toronto , ON M3J 1P3 , Canada.,Department of Chemistry and Biochemistry , University of Windsor , 401 Sunset Avenue , Windsor , ON N9B 3P4 , Canada
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Ma Y, Xu S, Wang X, Liu M, Li YX, Xin XL, Jin QH. Synthesis, Structures, and Luminescent Properties of Lanthanide Complexes with Triphenylphospine Oxide. Z Anorg Allg Chem 2017. [DOI: 10.1002/zaac.201700109] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Yan Ma
- Department of Chemistry; Capital Normal University; 100048 Beijing P. R. China
| | - Shan Xu
- Department of Chemistry; Capital Normal University; 100048 Beijing P. R. China
| | - Xin Wang
- Department of Chemistry; Capital Normal University; 100048 Beijing P. R. China
| | - Min Liu
- The College of Materials Science and Engineering; Beijing University of Technology; 100124 Beijing P. R. China
| | - Yue-Xue Li
- Department of Chemistry; Capital Normal University; 100048 Beijing P. R. China
| | - Xiu-Lan Xin
- School of Food and Chemical Engineering; Beijing Technology and Business University; 100048 Beijing P. R. China
| | - Qiong-Hua Jin
- Department of Chemistry; Capital Normal University; 100048 Beijing P. R. China
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Syntheses, structures, luminescence, NMR spectra and terahertz time-domain spectroscopy of nine lanthanide triflate complexes of tetrakis(O-isopropyl)methylenedisphosphonate with a L:Ln ratio of 4:1. Polyhedron 2015. [DOI: 10.1016/j.poly.2014.11.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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4
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Zheng S, Pfaendtner J. Enhanced sampling of chemical and biochemical reactions with metadynamics. MOLECULAR SIMULATION 2014. [DOI: 10.1080/08927022.2014.923574] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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5
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Gas-Phase Ion Chemistry of Rare Earths and Actinides. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/b978-0-444-63256-2.00263-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Motta A, Fragalà IL, Marks TJ. Insight into Group 4 Metallocenium-Mediated Olefin Polymerization Reaction Coordinates Using a Metadynamics Approach. J Chem Theory Comput 2013; 9:3491-7. [DOI: 10.1021/ct400259a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alessandro Motta
- Dipartimento
di Scienze Chimiche, Università di Catania, and INSTM, UdR Catania, Viale A. Doria 6, 95125
Catania, Italy
| | - Ignazio L. Fragalà
- Dipartimento
di Scienze Chimiche, Università di Catania, and INSTM, UdR Catania, Viale A. Doria 6, 95125
Catania, Italy
| | - Tobin J. Marks
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
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Flick TG, Donald WA, Williams ER. Electron capture dissociation of trivalent metal ion-peptide complexes. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2013; 24:193-201. [PMID: 23283726 PMCID: PMC3570592 DOI: 10.1007/s13361-012-0507-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 09/14/2012] [Accepted: 09/16/2012] [Indexed: 05/04/2023]
Abstract
With electrospray ionization from aqueous solutions, trivalent metal ions readily adduct to small peptides resulting in formation of predominantly (peptide + M(T) - H)(2+), where M(T) = La, Tm, Lu, Sm, Ho, Yb, Pm, Tb, or Eu, for peptides with molecular weights below ~1000 Da, and predominantly (peptide + M(T))(3+) for larger peptides. ECD of (peptide + M(T) - H)(2+) results in extensive fragmentation from which nearly complete sequence information can be obtained, even for peptides for which only singly protonated ions are formed in the absence of the metal ions. ECD of these doubly charged complexes containing M(T) results in significantly higher electron capture efficiency and sequence coverage than peptide-divalent metal ion complexes that have the same net charge. Formation of salt-bridge structures in which the metal ion coordinates to a carboxylate group are favored even for (peptide + M(T))(3+). ECD of these latter complexes for large peptides results in electron capture by the protonation site located remotely from the metal ion and predominantly c/z fragments for all metals, except Eu(3+), which undergoes a one electron reduction and only loss of small neutral molecules and b/y fragments are formed. These results indicate that solvation of the metal ion in these complexes is extensive, which results in the electrochemical properties of these metal ions being similar in both the peptide environment and in bulk water.
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Affiliation(s)
| | | | - Evan R. Williams
- Address reprint requests to Prof. Evan R. Williams: Department of Chemistry, University of California, Berkeley, Latimer Hall #1460, Berkeley, CA 94720-1460, Phone: 510-643-7161, Fax: (510) 542-7714,
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Verkerk UH, Zhao J, Saminathan IS, Lau JKC, Oomens J, Hopkinson AC, Siu KWM. Infrared multiple-photon dissociation spectroscopy of tripositive ions: lanthanum-tryptophan complexes. Inorg Chem 2012; 51:4707-10. [PMID: 22455512 DOI: 10.1021/ic2026973] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Collision-induced charge disproportionation limits the stability of triply charged metal ion complexes and has thus far prevented successful acquisition of their gas-phase IR spectra. This has curtailed our understanding of the structures of triply charged metal complexes in the gas phase and in biological environments. Herein we report the first gas-phase IR spectra of triply charged La(III) complexes with a derivative of tryptophan (N-acetyl tryptophan methyl ester), and an unusual dissociation product, a lanthanum amidate. These spectra are compared with those predicted using density functional theory. The best structures are those of the lowest energies that differ by details in the π-interaction between La(3+) and the indole rings. Other binding sites on the tryptophan derivative are the carbonyl oxygens. In the lanthanum amidate, La(3+) replaces an H(+) in the amide bond of the tryptophan derivative.
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Affiliation(s)
- Udo H Verkerk
- Department of Chemistry and Centre for Research in Mass Spectrometry, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
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Saminathan IS, Zhao J, Siu KWM, Hopkinson AC. Doubly charged protonated a ions derived from small peptides. Phys Chem Chem Phys 2011; 13:18307-14. [PMID: 21773645 DOI: 10.1039/c1cp21522a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Protonated a(2) and a(3) (therefore doubly charged) ions in which both charges lie on the peptide backbone are formed in collision-induced dissociations of [La(III)(peptide)(CH(3)CN)(m)](3+) complexes. Abundant (a(3)+H)(2+) ions are formed from triproline (PPP) and peptides with a proline residue at the N-terminus; these peptides are the most effective in producing ions of the type (a(2)+H)(2+) and (a(3)+H)(2+). A systematic study of the effect of the location of the proline residue and other residues of aliphatic amino acids on the generation of protonated a ions is reported. Density functional theory calculations at B3LYP/6-311++G(d,p) gave the proton affinity of the a(3) ion derived from PPP to be 167.6 kcal mol(-1), 2.6 kcal mol(-1) higher than that of water. The protonated a(2) ions of diglycine and diproline and a(3) ions of triglycine have lower proton affinities and are only observed in lower abundances, possibly due to proton transfer to water in ion-molecule reactions.
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Affiliation(s)
- Irine S Saminathan
- Department of Chemistry and Centre for Research in Mass Spectrometry, York University, 4700 Keele Street, Toronto, Canada M3J 1P3
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Barducci A, Bonomi M, Parrinello M. Metadynamics. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2011. [DOI: 10.1002/wcms.31] [Citation(s) in RCA: 712] [Impact Index Per Article: 54.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Alessandro Barducci
- Computational Science, Department of Chemistry and Applied Biosciences, ETH Zurich, USI Campus, Lugano, Switzerland
| | - Massimiliano Bonomi
- Computational Science, Department of Chemistry and Applied Biosciences, ETH Zurich, USI Campus, Lugano, Switzerland
| | - Michele Parrinello
- Computational Science, Department of Chemistry and Applied Biosciences, ETH Zurich, USI Campus, Lugano, Switzerland
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Knapp-Mohammady M, Young AB, Paizs B, Harrison AG. Fragmentation of doubly-protonated Pro-His-Xaa tripeptides: formation of b(2)(2+) ions. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2009; 20:2135-2143. [PMID: 19683937 DOI: 10.1016/j.jasms.2009.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Revised: 06/29/2009] [Accepted: 07/01/2009] [Indexed: 05/28/2023]
Abstract
When ionized by electrospray from acidic solutions, the tripeptides Pro-His-Xaa (Xaa = Gly, Ala, Leu) form abundant doubly-protonated ions, [M + 2H]2+. Collision-induced dissociation (CID) of these doubly-protonated species results, in part, in formation of b(2)(2+) ions, which fragment further by loss of CO to form a(2)(2+) ions; the latter fragment by loss of CO to form the Pro and His iminium [immonium is commonly used in peptide MS work] ions. Although larger doubly-charged b ions are known, this represents the first detailed study of b(2)(2+) ions in CID of small doubly protonated peptides. The most abundant CID products of the studied doubly-protonated peptides arise mainly in charge separation involving two primary fragmentation channels, formation of the b2/y1 pair and formation of the a1/y2 pair. Combined molecular dynamics and density functional theory calculations are used to gain insight into the structures and fragmentation pathways of doubly-protonated Pro-His-Gly including the energetics of potential protonation sites, backbone cleavages, post-cleavage charge-separation reactions and the isomeric structures of b(2)(2+) ions. Three possible structures are considered for the b(2)(2+) ions: the oxazolone, diketopiperazine, and fused ring isomers. The last is formed by cleavage of the His-Gly amide bond on a pathway that is initiated by nucleophilic attack of one of the His side-chain imidazole nitrogens. Our calculations indicate the b(2)(2+) ion population is dominated by the oxazolone and/or fused ring isomers.
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Zhao J, Siu CK, Shi T, Hopkinson AC, Siu KWM. Abundant Dipositively Charged Protonated a2 and a3 Ions from Diproline and Triproline. J Phys Chem B 2009; 113:4963-9. [DOI: 10.1021/jp900767k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Junfang Zhao
- Department of Chemistry and Centre for Research in Mass Spectrometry, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
| | - Chi-Kit Siu
- Department of Chemistry and Centre for Research in Mass Spectrometry, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
| | - Tujin Shi
- Department of Chemistry and Centre for Research in Mass Spectrometry, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
| | - Alan C. Hopkinson
- Department of Chemistry and Centre for Research in Mass Spectrometry, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
| | - K. W. Michael Siu
- Department of Chemistry and Centre for Research in Mass Spectrometry, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3
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