title: Precision profiling and identification of human serum peptides using Fourier transform ion cyclotron resonance mass spectrometry.
abstract: Many biomarker discovery studies are based on matrix-assisted laser desorption/ionisation (MALDI) peptide profiles. In this study, 96 human serum samples were analysed on a Bruker solariX(TM) MALDI Fourier transform ion cyclotron resonance (FTICR) system equipped with a 15 tesla magnet. Isotopically resolved peptides were observed in ultrahigh resolution FTICR profiles up to m/z 6500 with mass measurement errors (MMEs) of previously identified peptides at a sub-ppm level. For comparison with our previous platform for peptide profile mass analysis (i.e. Ultraflex II) the corresponding time-of-flight (TOF) spectra were obtained with isotopically resolved peptides up to m/z 3500. The FTICR and TOF systems performed rather similar with respect to the repeatability of the signal intensities. However, the mass measurement precision improved at least 10-fold in ultrahigh resolution data and thus simplified spectral alignment necessary for robust and quantitatively precise comparisons of profiles in large-scale clinical studies. From each single MALDI-FTICR spectrum an m/z-list was obtained with sub-ppm precision for all different species, which is beneficial for identification purposes and interlaboratory comparisons. Furthermore, the FTICR system allowed new peptide identifications from collision-induced dissociation (CID) spectra using direct infusion of reversed-phase (RP) C(18)-fractionated serum samples on an electrospray ionisation (ESI) source.
authors.affiliation: Department of Parasitology, Leiden University Medical Center (LUMC), Biomolecular Mass Spectrometry Unit, Albinusdreef 2, 2300 RC Leiden, The Netherlands.
authors.forename: Simone
authors.initials: S
authors.lastname: Nicolardi
authors.forename: Magnus
authors.initials: M
authors.lastname: Palmblad
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Hensbergen
authors.forename: Rob A E M
authors.initials: RA
authors.lastname: Tollenaar
authors.forename: André M
authors.initials: AM
authors.lastname: Deelder
authors.forename: Yuri E M
authors.initials: YE
authors.lastname: van der Burgt
mesh_terms: D000595:Amino Acid Sequence; D015415:Biomarkers / Q000097:blood; D056148:Chromatography, Reverse-Phase; D004867:Equipment Design; D005583:Fourier Analysis; D006801:Humans; D008969:Molecular Sequence Data; D010455:Peptides / Q000097:blood*; D015203:Reproducibility of Results; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation / Q000379:methods*
chemical_list: D015415:Biomarkers; D010455:Peptides