title: Benefits of 2.94 micron infrared matrix-assisted laser desorption/ionization for analysis of labile molecules by Fourier transform mass spectrometry.
abstract: A 2.94 microm Er:YAG laser was used together with a commercial Fourier transform mass spectrometer to study labile biomolecules. The combination has shown superior performance over conventional 337 nm ultraviolet matrix-assisted laser desorption/ionization (UV-MALDI) Fourier transform mass spectrometry (FTMS), especially for the analysis of peptides with post-translational modifications. With succinic acid as a matrix, the sensitivity of the single-shot analysis was increased by an order of magnitude to the low femtomole level, with significantly less fragmentation observed. Intact molecular ions of a range of O-glycosylated and sulfated peptides were detected. Urea was found to induce even less fragmentation, although at the expense of the total ion yield. Molecular ions of a noncovalent complex (vancomycin + diacetyl-L-Lys-D-Ala-D-Ala) have been observed for the first time in MALDI-FTMS. 2.94 microm infrared (IR) MALDI also produced abundant molecular ions of a range of nonbiological samples, including C60 and C70 fullerenes as well as dimetal coordination complexes.
authors.affiliation: Department of Chemistry, University of Southern Denmark/Odense University.
authors.forename: B A
authors.initials: BA
authors.lastname: Budnik
authors.forename: K B
authors.initials: KB
authors.lastname: Jensen
authors.forename: T J
authors.initials: TJ
authors.lastname: Jørgensen
authors.forename: A
authors.initials: A
authors.lastname: Haase
authors.forename: R A
authors.initials: RA
authors.lastname: Zubarev
mesh_terms: D002138:Calibration; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D010455:Peptides / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D019802:Succinic Acid / Q000032:analysis*; D014508:Urea / Q000032:analysis*; D014640:Vancomycin / Q000032:analysis
chemical_list: D010455:Peptides; D014640:Vancomycin; D014508:Urea; D019802:Succinic Acid