Journal of the American Society for Mass Spectrometry

, Volume 16, Issue 11, pp 1787–1794

Combined ion-mobility and mass-spectrometry investigations of metallothionein complexes using a tandem mass spectrometer with a segmented second quadrupole

  • Yuzhu Guo
  • Yun Ling
  • Bruce A. Thomson
  • K. W. Michael Siu
Article

DOI: 10.1016/j.jasms.2005.07.011

Cite this article as:
Guo, Y., Ling, Y., Thomson, B.A. et al. J Am Soc Mass Spectrom (2005) 16: 1787. doi:10.1016/j.jasms.2005.07.011

Abstract

Rabbit metallothionein (MT) 2A complexes with Cd(II), Zn(II), Ag(I), Cu(I), Hg(II), arsenite, monomethylarsonous acid (MMA), and dimethylarsinous acid (DMA) have been examined using ion-mobility measurements and mass spectrometry in a triple-quadrupole mass spectrometer equipped with a segmented second quadrupole that doubled as an ion-mobility cell [Guo, Y.; Wang, J.; Javahery, G.; Thomson, B. A.; Siu, K. W. M. An Ion-Mobility Spectrometer with Radial Collisional Focusing. Anal. Chem.2005, 77, 266–275]. The metal ions confer conformational rigidity on the MT complexes, which counteracts Coulombic repulsion among protons added as a result of electrospray. Triply and quadruply protonated Cd7MT2A have smaller cross-sections than the Cd7MT2A structure deduced from published NMR data. For the 6+ ions, the As6MT2A complex has a cross-section of 790 Å2; the MMA10MT2A complex, 920 Å2; and the DMA20MT2A complex, 1220 Å2. This increase in cross-section of the As(III) species, from As3+ to MMA to DMA, is interpreted as a consequence of decreasing multiple coordination and increasing number of methyl groups.

Download to read the full article text

Copyright information

© American Society for Mass Spectrometry 2005

Authors and Affiliations

  • Yuzhu Guo
    • 1
  • Yun Ling
    • 1
  • Bruce A. Thomson
    • 1
    • 2
  • K. W. Michael Siu
    • 1
  1. 1.Department of Chemistry and Center for Research in Mass SpectrometryYork UniversityTorontoCanada
  2. 2.MDS SCIEXConcordCanada
  3. 3.Department of ChemistryUniversity of British ColumbiaVancouverCanada