title: Advantages of external accumulation for electron capture dissociation in Fourier transform mass spectrometry.
abstract: A combination of external accumulation (XA) with electron capture dissociation (ECD) improves the electron capture efficiency, shortens the analysis time, and allows for rapid integration of multiple scans in Fourier transform mass spectrometry. This improves the signal-to-noise ratio and increases the number of detected products, including structurally important MS3 fragments. With XA-ECD, the range of the labile species amenable to ECD is significantly extended. Examples include the first-time determination of the positions of six GalNAc groups in a 60-residue peptide, five sialic acid and six O-linked GalNAc groups in a 25-residue peptide, and the sulfate group position in a 11-residue peptide. Even weakly bound supramolecular aggregates, including nonspecific peptide complexes, can be analyzed with XA-ECD. Preliminary results are reported on high-rate XA-ECD that uses an indirectly heated dispenser cathode as an electron source. This shortens the irradiation time to > or = 1 ms and increases the acquisition rate to 3 scans/s, an improvement by a factor of 10-100.
authors.affiliation: Department of Chemistry, University of Southern Denmark.
authors.forename: K F
authors.initials: KF
authors.lastname: Haselmann
authors.forename: B A
authors.initials: BA
authors.lastname: Budnik
authors.forename: J V
authors.initials: JV
authors.lastname: Olsen
authors.forename: M L
authors.initials: ML
authors.lastname: Nielsen
authors.forename: C A
authors.initials: CA
authors.lastname: Reis
authors.forename: H
authors.initials: H
authors.lastname: Clausen
authors.forename: A H
authors.initials: AH
authors.lastname: Johnsen
authors.forename: R A
authors.initials: RA
authors.lastname: Zubarev
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000737:chemistry; D000595:Amino Acid Sequence; D001839:Bombesin / Q000737:chemistry; D005583:Fourier Analysis; D006031:Glycosylation; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D008555:Melitten / Q000737:chemistry; D008969:Molecular Sequence Data; D018396:Mucin-1 / Q000737:chemistry; D010446:Peptide Fragments / Q000032:analysis*
chemical_list: D018396:Mucin-1; D010446:Peptide Fragments; D008555:Melitten; D000324:Adrenocorticotropic Hormone; D001839:Bombesin