title: Automated assignment of ionization states in broad-mass matrix-assisted laser desorption/ionization spectra of protein mixtures.
abstract: A computational technique is presented for the automated assignment of the multiple charge and multimer states (ionization states) in the time-of-flight (TOF) domain for matrix-assisted laser desorption/ionization (MALDI) spectra. Examples of the application of this technique include an improved, automatic calibration over the 2 to 70 kDa mass range and a reduced data redundancy after reconstruction of the molecular spectrum of only singly charged monomers. This method builds on our previously reported enhancement of broad-mass signal detection, and includes two steps: (1) an automated correction of the instrumental acquisition initial time delay, and (2) a recursive TOF detection of multiple charge states and singly charged multimers of molecular [MH](+) ions over the entire record range, based on MALDI methods. The technique is tested using calibration mixtures and pooled serum quality control samples acquired along with clinical study data. The described automated procedure improves the analysis and dimension reduction of MS data for comparative proteomics applications.
authors: Department of Applied Science, College of William and Mary, Williamsburg, VA 23187-8795, USA. dimaly@wm.edu
authors: Dariya I
authors: DI
authors: Malyarenko
authors: William E
authors: WE
authors: Cooke
authors: Christine L
authors: CL
authors: Bunai
authors: Dennis M
authors: DM
authors: Manos
mesh_terms: D000465:Algorithms; D000595:Amino Acid Sequence; D045424:Complex Mixtures / Q000032:analysis / Q000737:chemistry; D007477:Ions; D008969:Molecular Sequence Data; D010449:Peptide Mapping / Q000379:methods*; D011506:Proteins / Q000032:analysis* / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D045424:Complex Mixtures; D007477:Ions; D011506:Proteins