Abstract
The [M − nH + mNa](m−n)+ and [M − nH + mK](m−n)+ ions are common in the electrospray mass spectra of proteins and peptides. The feasibility of forming these ions in the gas phase via collision activation and/or ion-molecule reaction is investigated. Sodium and potassium affinities of the N-methylacetamide anion, the acetate anion, and the 1-propanamide anion have been calculated using density functional theory at the B3LYP/6-311+ +G(d,p) level of theory. These anions were chosen as models for the functional groups on a protein or peptide. These affinity values are then used to calculate reaction enthalpies of alkali hydroxides, chlorides, and hydrates with N-methylacetamide, acetic acid, the acetate anion, and 1-propanamine, model reactions that may lead to formation of the [M − nH + mNa](m−n)+ and [M − nH + mK](m−n)+ ions. It is found that a number of these reactions are exothermic or slightly endothermic (ΔH 0 < + 20 kcal/mol) and are accessible after collision activation in the lens region. The potential energy hypersurfaces of model reactions between NaOH and formamide as well as NaCl and formamide show relatively flat surfaces devoid of significant barriers.
Similar content being viewed by others
References
Fenn, J. B.; Mann, M.; Meng, C. K.; Wong, S. F.; Whitehouse, C. M. Science 1989, 246, 64–70.
Kebarle, P.; Ho, Y. In Electrospray Ionization Mass Spectrometry; Cole, R. B., Ed.; Wiley: New York, 1997; pp 3–63.
Smith, R. D.; Loo, J. A.; Ogorzalek Loo, R. R.; Busman, M.; Udseth, H. R. Mass Spectrom. Rev. 1991, 10, 359–451.
Neubauer, G.; Anderegg, R. J. Anal. Chem. 1994, 66, 1056–1061.
Rodriquez, C. F.; Fournier, R.; Chu, I. K.; Hopkinson, A. C.; Siu, K. W. M. Int. J. Mass Spectrom. 1999, 192, 303–317.
Sigel, H.; Martin, R. B. Chem. Rev. 1982, 82, 385–426.
Becke, A. D. J. Chem. Phys. 1993, 98, 5648–5652.
Lee, C.; Yang, W.; Parr, R. G. Phys. Rev. B 1988, 37, 785–789;
Miehlich, B.; Savin, A.; Stoll, H.; Preuss, H. Chem. Phys. Lett. 1989, 157, 200–206.
Krishnan, R.; Binkley, J. S.; Seeger, R.; Pople, J. J. Chem. Phys. 1980, 72, 650–654;
McLean, A. D.; Chandler, G. S. J. Chem. Phys. 1980, 72, 5639–5648;
Chandrasekhar, J.; Andrade, J. G.; Schleyer, P. v. R. J. Am. Chem. Soc. 1981, 103, 5609–5612.
Chandrasekhar, J.; Spitznagel, G. W.; Schleyer, P. v. R. J. Comput. Chem. 1983, 4, 294–301.
Curtiss, L. A.; McGrath, M. P.; Blaudeau, J. P.; Davis, N. E.; Binning, R. C., Jr.; Radom, L. J. Chem. Phys. 1995, 103, 6104–6113.
Gaussian 98, Revision A.5: Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Zakrzewski, V. G.; Montgomery, J. A.; Stratmann, R. E., Jr.; Burant, J. C.; Dapprich, S.; Millam, J. M.; Daniels, A. D.; Kudin, K. N.; Strain, M. C.; Farkas, O.; Tomasi, J.; Barone, V.; Cossi, M.; Cammi, R.; Mennucci, B.; Pomelli, C.; Adamo, C.; Clifford, S.; Ochterski, J.; Petersson, G. A.; Ayala, P. Y.; Cui, Q.; Morokuma, K.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.; Foresman, J. B.; Cioslowski, J.; Ortiz, J. V.; Stefarnov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.; Gomperts, R.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.; Gonzalez, C.; Challacombe, M.; Gill, P. M. W.; Johnson, B.; Chen, W.; Wong, M. W.; Andres, J. L.; Gonzalez, C.; Head-Gordon, M.; Replogle, E. S.; Pople, J. A., Gaussian Inc., Pittsburgh, PA, 1998.
Lias, S. G.; Bartmess, J. E.; Liebman, J. F.; Holmes, J. L.; Levin, R. D.; Mallard, W. G. J. Phys. Chem. Ref. Data 1988, 17, Suppl. 1.
Lias, S. G.; Lieman, J. F.; Levin, R. D.; Kafafi, S. A. NIST Standard Reference Database 25, Version 2.02, 1994.
Bartmess, J. E. NIST Standard Reference Database 19B, Version 3.01, 1993.
Hunter, E. P.; Lias, S. G. In NIST Chemistry WebBook, http://webbook.nist.gov/chemistry/;
Hunter, E. P.; Lias, S. G. J. Phys. Chem. Ref. Data 1998, 27, 413–656.
Shoeib, T.; Milburn, R. K.; Koyanagi, G. K.; Lavrov, V. V.; Bohme, D. K.; Siu, K. W. M.; Hopkinson, A. C. Int. J. Mass Spectrom. 2000, 201, 87–100.
Holland, P. M.; Castleman, A. W., Jr. J. Chem. Phys. 1982, 76, 4195–4205.
El Aribi, H.; Shoeib, T.; Ling, Y; H.; Hopkinson, A. C.; Siu, K. W. M. Proceedings of the 48th ASMS Conference on Mass Spectrometry and Allied Topics, Long Beach, California, June 11–15, 2000.
Rodgers, M. T.; Armentrout, P. B. J. Phys. Chem. A 1997, 101, 2614–2625.
Iribarne, J. V.; Thomson, B. A. J. Chem. Phys. 1976, 64, 2287–2294.
Zhan, D.; Rosell, J.; Fenn, J. B. J. Am. Soc. Mass Spectrom. 1998, 9, 1241–1247.
Rodriguez-Cruz, S. E.; Klassen, J. S.; Williams, E. R. J. Am. Soc. Mass Spectrom. 1999, 10, 958–968.
Simulation was performed on a proprietary program of MDS SCIEX for modeling transport of ions through quadrupoles.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Rodriquez, C.F., Guo, X., Shoeib, T. et al. Formation of [M − nH + mNa](m−n)+ and [M − nH + mK](m−n)+ ions in electrospray mass spectrometry of peptides and proteins. J. Am. Soc. Spectrom. 11, 967–975 (2000). https://doi.org/10.1016/S1044-0305(00)00162-8
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1016/S1044-0305(00)00162-8