title: Peptide sequence determination by matrix-assisted laser desorption ionization employing a tandem double focusing magnetic-Orthogonal acceleration time-of-flight mass spectrometer.
abstract: This report describes the fragmentation processes for peptides induced by collisional activation of the (12)C isobar of matrix-assisted laser desorption ionization (MALDI)-generated pseudomolecular ions employing an EBE orthogonal acceleration time-of-flight mass spectrometer and using xenon as the collision gas at a laboratory collision energy of 800 eV. These MALDI-collision-induced dissociation (CID) spectra are shown to provide sequence information of comparable quality to those obtained by using high energy CID conditions with liquid secondary ionization mass spectrometry on a four-sector tandem instrument. Peptide sequencing via MALDI-CID is demonstrated on three tryptic peptides obtained from a bacterial protein (P450 isozyme) of unknown sequence. Sensitivity is shown to be at the 1 pmol level for standard peptides.
authors.affiliation: Department of Pharmaceutical Chemistry, Mass Spectrometry Facility, University of California, San Francisco, San Francisco, California, USA.
authors.forename: K F
authors.initials: KF
authors.lastname: Medzihradszky
authors.forename: G W
authors.initials: GW
authors.lastname: Adams
authors.forename: A L
authors.initials: AL
authors.lastname: Burlingame
authors.forename: R H
authors.initials: RH
authors.lastname: Bateman
authors.forename: M R
authors.initials: MR
authors.lastname: Green