MoO-05

CHARACTERIZATION OF PROTEIN DIGESTS USING NOVEL SCANNING FUNCTIONS

David E Smith, Lydia Nuwaysir, Mark Allen*, Joe Anacleto*, Ron Bonner*, Bori Shushan*

Perkin-Elmer, Applied Biosystems Division, 850 Lincoln Centre Drive, Foster City, California, USA, 94404

*Perkin-Elmer SCIEX Instruments, 71 Four Valley Drive, Concord, Ontario, Canada, L4K 4V8

Use of a novel single quadrupole benchtop IonSprayTM/MS system (PE-SCEX API 100) for the characterization of protein digests will be described. Three examples of the LC/MS of protein tryptic digests will be presented demonstrating the identification of sites of glycosylation in fetuin; the identification of sites of phosphorylation in ß-casein; and the determination of the entire protein sequence of cytochrome-C using CID/MS and a sophisticated automated data base searching routine.

The API 100 system offers the ability to run a variety of scan modes simultaneously. These mixed-mode experiments allow the use of different scanning parameters within a single run. The present set of data describes how such experirnents can be applied to the characterization of proteins and peptides. These experiments involve the LC/MS of protein tryptic digests while combining different scan and ion source conditions in a continuous loop. The ionization source used in all experiments is IonSpray (ofen referred to as pneumatically assisted electrospray).

References:

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  2. M.J. Huddleston, R.S. Anna, M.F. Bean and S.A. Carr, J. Am. Soc. Mass Spectrom. (1993) 4, 710-717
  3. M. Mann and M. Wilm, Anal. Chem (1994) 66, 4390-4399