Abstract
The coupling of electrospray ionization with Fourier-transform mass spectrometry allows the analysis of large biomolecules with mass-measuring errors of less than 1 ppm. The large number of atoms incorporated in these molecules results in a low probability for the all-monoisotopic species. This produces the potential to misassign the number of heavy isotopes in a specific peak and make a mass error of ±1 Da, although the certainty of the measurement beyond the decimal place is greater than 0.1 Da. Statistical tests are used to compare the measured isotopic distribution with the distribution for a model molecule of the same average molecular mass, which allows the assignment of the monoisotopic mass, even in cases where the monoisotopic peak is absent from the spectrum. The statistical test produces error levels that are inversely proportional to the number of molecules in a distribution, which allows an estimation of the number of ions in the trapped ion cell. It has been determined, via this method that 128 charges are required to produce a signal-to-noise ratio of 3:1, which correlates well with previous experimental methods.
Article PDF
Similar content being viewed by others
References
Teer, D.; Dole, M. J. Polym. Sci. 1975, 13, 985.
Fenn, J. B.; Mann, M.; Meng, C. K.; Wong, S. F.; Whitehouse, C. M. Science 1989, 246, 64.
Huang, E. C.; Henion, J. D. J. Am. Soc. Mass Spectrom. 1990, 1, 158.
Smith, R. D.; Loo, J. A.; Ogorzalek Loo, R. R.; Busman, M.; Udseth, H. R. Mass Spectrom. Rev. 1991, 10, 359–451.
Karas, M.; Bachmann, D.; Bahr, U.; Hillenkamp, F. Int. J. Mass Spectrom. Ion Processes 1987, 78, 53–68.
Hillenkamp, F.; Karas, M.; Beavis, R. C.; Chait, B. T. Anal. Chem. 1991, 63, A1193-A1203.
Loo, J. A.; Udseth, H. R.; Smith, R. D. Anal. Biochem. 1989, 179, 404–412.
Smith, R. D.; Loo, J. A.; Edmonds, C. G.; Barinaga, C. J.; Udseth, H. R. Anal. Chem. 1990, 62, 882–899.
Loo, J. A.; Edmonds, C. G.; Smith, R. D. Anal. Chem. 1991, 63, 2488–2499.
Beavis, R. C. Anal. Chem. 1993, 65, 496–497.
Henry, K. D.; Williams, E. R.; Wang, B. H.; McLafferty, F. W.; Shabanowitz, J.; Hunt, D. F. Proc. Natl. Acad. Sci., U. S. A. 1989, 86, 9075.
Henry, K. D.; Quinn, J. P.; McLafferty, F. W. J. Am. Chem. Soc. 1991, 113, 5447–5449.
Beu, S. C.; Senko, M. W.; Quinn, J. P.; McLafferty, F. W. J. Am. Soc. Mass Spectrom. 1993, 4, 190.
Cody, R. B.; Tamura, J.; Musselman, B. D. Anal. Chem. 1992, 64, 1561–1570.
Dobberstein, P.; Schroeder, E. Rapid Commun. Mass Spectrom. 1993, 7, 861–864.
Zubarev, R. A.; Bondarenko, P. V. Rapid Commun. Mass Spectrom. 1991, 5, 276.
Limbach, P. A.; Grosshans, P. B.; Marshall, A. G. Anal. Chem. 1993, 65, 135.
Beu, S. C.; Senko, M. W.; Quinn, J. P.; Wampler, F. M.; McLafferty, F. W. J. Am. Soc. Mass Spectrom. 1993, 4, 557–565.
Yergey, J. A. Int. J. Mass Spectrom. Ion Phys. 1983, 52, 337.
Protein Identification Resource, National Biomedical Research Foundation.
Labowski, M.; Whitehouse, C. M.; Fenn, J. B. Rapid Commun. Mass Spectrom. 1993, 7, 71.
Naito, Y.; Inoue, M. J. Mass Spectrom. Soc. Jpn. 1994, 42, 1–9.
Zaia, J.; Annan, R. S.; Biemann, K. Rapid Commun. Mass Spectrom. 1992, 6, 32.
Beu, S. C.; Laude, D. A. Int. J. Mass Spectrom. Ion Processes 1992, 112, 215–230.
Grosshans, P. B.; Shields, P. J.; Marshall, A. G. J. Chem. Phys. 1991, 94, 5341–5352.
Bruce, J. E.; Cheng, X.; Bakhtiar, R.; Wu, Q.; Hofstadler, S. A.; Anderson, G. A.; Smith, R. D. J. Am. Chem. Soc. 1994, 116, 7839–7847.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Senko, M.W., Beu, S.C. & McLaffertycor, F.W. Determination of monoisotopic masses and ion populations for large biomolecules from resolved isotopic distributions. J Am Soc Mass Spectrom 6, 229–233 (1995). https://doi.org/10.1016/1044-0305(95)00017-8
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1016/1044-0305(95)00017-8