Investigations of gas-phase lithium-peptide adducts: Tandem. mass spectrometry and semiempirical studies

  • Julie A. Leary
  • Zhongrui Zhou
  • Sherri A. Ogden
  • Todd D. Williams


Tandem mass spectrometry using a hybrid mass spectrometer of BEqQ geometry was used to investigate the gas-phase formation of the [An+ Li − H)+ ion from lithium-peptide adducts. High resolution mass measurements as well as precursor and product ion scans of five peptides indicate that one source of [An+ Li − H) arises from [An+ Li]+. Semiempirical calculations (MNOO) and metastable ion decomposition studies of the peptide Gly-Gly-Gly show that the lithium ion prefers to coordinate to the three internal carbonyls of the neutral molecule to give a species that is energetically more stable than the lithiated zwitterion by 305 kJ/mol. Theoretical and experimental evidence suggest that the monolithiated precursor ion population may be a distribution of structural isomers. (J Am Soc Mass Spectrom 1990, 1, 473-480)


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  1. 1.
    Tang, X.; Ens, W.; Standing, K. G.; Westmore, J. B. Anal. Chern. 1988, 60, 1791.CrossRefGoogle Scholar
  2. 2.
    Russell, D. H.; McGlohon, E. S.; Mallis, L. M. Anal. Chem. 1988, 60, 1818.CrossRefGoogle Scholar
  3. 3.
    Renner, D.; Spitteller, G. Biomed. Environ. Mass Specirom. 1988, 15, 75.CrossRefGoogle Scholar
  4. 4.
    Grese, R. P.; Cerny, R. L.; Gross, M. L. J. Am. Chem. Soc. 1989, 111, 2835.CrossRefGoogle Scholar
  5. 5.
    Leary, J. A.; Williams, T. D.; Bott, G. Rapid Commun. Mass. Spec. 1989, 3, 192.CrossRefGoogle Scholar
  6. 6.
    Thome, G. C.; Gaskell, S. J. Rapid Commun. Mass Spec. 1989, 3, 217.CrossRefGoogle Scholar
  7. 7.
    Clark, T. A Handbook of Computational Chemistry; John Wiley: New York, 1985.Google Scholar
  8. 8.
    Meulemans, P. R.; Piret, P.; Van Meerssche, M. Acta. Cryst. 1971, B27, 1187.Google Scholar
  9. 9.
    Wright, L. R.; Berkman, R. P. J. Phys. Chem. 1982, 86, 3956.CrossRefGoogle Scholar
  10. 10.
    Johnson, R. S.; Martin, S. A.; Biemann, K Int. J. Mass. Spectrom. Ion Prac. 1988, 86, 137.CrossRefGoogle Scholar
  11. 11.
    Roepstorff, P.; Pohlman, J. Biomed. Mass. Specirom, 1984, 11, 601.CrossRefGoogle Scholar
  12. 12.
    Tse, Y-C.; Newton, M. D.; Vishveshwara, S.; Pople, J. A. J. Am. Chem. Soc. 1978, 100, 4329.CrossRefGoogle Scholar
  13. 13.
    Setzer, W. N.; Schleyer, P. V. R. Adv. Organomet. Chem. 1985, 24, 353 (and references therein).CrossRefGoogle Scholar
  14. 14.
    Thorne, G. C.. Ballard. K. D.; Gaskell, S. T. J. Am. Soc. Mass Spectrom. 1990, in press.Google Scholar

Copyright information

© American Society for Mass Spectrometry 1990

Authors and Affiliations

  • Julie A. Leary
    • 1
  • Zhongrui Zhou
    • 1
  • Sherri A. Ogden
    • 1
  • Todd D. Williams
    • 1
  1. 1.College of ChemistryUniversity of CaliforniaBerkeleyUSA

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