search scholar.google.com.

Papers Published

1. Schwartz, BL; Bruce, JE; Anderson, GA; Hofstadler, SA; Rockwood, AL; Smith, RD; Chilkoti, A; Stayton, PS, Dissociation of tetrameric ions of noncovalent streptavidin complexes formed by electrospray ionization., Journal of the American Society for Mass Spectrometry, vol. 6 no. 6 (June, 1995), pp. 459-465 [1044-0305(95)00191-F], [doi] .
   (last updated on 2024/04/23)

   Abstract:
   The noncovalent tetrameric association of the protein streptavidin formed by electrospray ionization (ESI) mass spectrometry has been observed intact and dissociated in the gas phase. An extended mass-to-charge ratio range quadrupole mass spectrometer was employed to examine the effects of harsher conditions in the ESI atmosphere-vacuum interface region on the streptavidin tetramer. Thermally induced dissociation caused the mass spectra to exhibit a series of complementary monomer and trimer ions that correspond to decomposition of the tetrameric species. Similar results were obtained with tandem mass spectrometric experiments on a Fourier transform ion cyclotron resonance mass spectrometer by application of sustained off-resonance irradiation (SORI) on a selected tetrameric charge state. The technique of single-frequency quadrupole excitation was used to accomplish selected-ion accumulation of the 14 + charge state of the tetramer during ion injection. Subsequent low energy SORI combined with broadband quadrupole cooling produced the 7 + monomer and 7 + trimer species, as well as the 6 + monomer and 8 + trimer complementary ions. The observed asymmetric breakup of the tetramer is qualitatively explained by using physical models.