title: Analysis of proteins by direct-scanning infrared-MALDI mass spectrometry after 2D-PAGE separation and electroblotting.
abstract: A novel approach is reported for the analysis and identification of proteins separated by 2D-PAGE with scanning infrared matrix-assisted laser desorption/ionization mass spectrometry (scanning IR-MALDI-MS). The proteins of human blood plasma were separated by 2D-PAGE, electroblotted onto PVDF membranes, incubated in matrix solution, and then scanned by IR-MALDI-MS. Mass contour plots of selected spots were obtained. Protein separation is shown to be conserved by comparison with silver-stained gels. The sensitivity for the protein detection is comparable if not better than that of silver-stained gels. Posttranslational modifications were identified by comparing the measured mass to the one calculated from the known DNA sequence. Adduct formation to unprotected cysteine residues during gel separation is demonstrated for selected proteins.
authors.affiliation: Institute for Medical Physics and Biophysics, University of Münster, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Eckerskorn
authors.forename: K
authors.initials: K
authors.lastname: Strupat
authors.forename: D
authors.initials: D
authors.lastname: Schleuder
authors.forename: D
authors.initials: D
authors.lastname: Hochstrasser
authors.forename: J C
authors.initials: JC
authors.lastname: Sanchez
authors.forename: F
authors.initials: F
authors.lastname: Lottspeich
authors.forename: F
authors.initials: F
authors.lastname: Hillenkamp
mesh_terms: D001798:Blood Proteins / Q000032:analysis*; D015153:Blotting, Western / Q000379:methods*; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods*; D006801:Humans; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013055:Spectrophotometry, Infrared
chemical_list: D001798:Blood Proteins