title: Analysis of biomolecules by atmospheric pressure visible-wavelength MALDI-ion trap-MS in transmission geometry.
abstract: We report the development of a new AP visible-wavelength MALDI-ion trap-MS instrument with significantly improved performance over our previously reported system (Int. J. Mass Spectrom. 315, 66-73 (2012)). A Nd:YAG pulsed laser emitting light at 532 nm was used to desorb and ionize oligosaccharides and peptides in transmission geometry through a glass slide. Limits of detection (LODs) achieved in MS mode correspond to picomole quantities of oligosaccharides and femtomole quantities of peptides. Tandem MS (MS/MS) experiments enabled identification of enzymatically digested proteins and oligosaccharides by comparison of MS/MS spectra with data found in protein and glycan databases. Moreover, the softness of ionization, LODs, and fragmentation spectra of biomolecules by AP visible-wavelength MALDI-MS were compared to those obtained by AP UV MALDI-MS using a Nd:YAG laser emitting light at 355 nm. AP visible-wavelength MALDI appears to be a softer ionization technique then AP UV MALDI for the analysis of sulfated peptides, while visible-wavelength MALDI-MS, MS/MS, and MS/MS/MS spectra of other biomolecules analyzed were mostly similar to those obtained by AP UV MALDI-MS. Therefore, the methodology presented will be useful for MS and MS(n) analyses of biomolecules at atmospheric pressure. Additionally, the AP visible-wavelength MALDI developed can be readily used for soft ionization of analytes on various mass spectrometers.
authors.affiliation: Department of Chemistry, University of Toledo, Toledo, OH, 43606, USA.
authors.forename: Raymond E
authors.initials: RE
authors.lastname: West
authors.forename: Eric W
authors.initials: EW
authors.lastname: Findsen
authors.forename: Dragan
authors.initials: D
authors.lastname: Isailovic
mesh_terms: D000818:Animals; D001274:Atmospheric Pressure; D002417:Cattle; D006736:Horses; D006801:Humans; D007477:Ions / Q000737:chemistry; D057230:Limit of Detection; D009844:Oligosaccharides / Q000032:analysis* / Q000737:chemistry; D010446:Peptide Fragments / Q000032:analysis* / Q000737:chemistry; D011506:Proteins / Q000032:analysis* / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D014357:Trypsin / Q000737:chemistry
chemical_list: D007477:Ions; D009844:Oligosaccharides; D010446:Peptide Fragments; D011506:Proteins; D014357:Trypsin
references.citation: Anal Chem. 2000 Feb 15;72(4):652-7
references.pmid: 10701247
references.citation: J Am Soc Mass Spectrom. 2013 Apr;24(4):609-14
references.pmid: 23397138
references.citation: Rapid Commun Mass Spectrom. 2007;21(24):4129-34
references.pmid: 18022962
references.citation: Anal Chem. 2010 Jun 15;82(12):4998-5001
references.pmid: 20469839
references.citation: Anal Chem. 2002 Apr 15;74(8):1891-5
references.pmid: 11985323
references.citation: J Mass Spectrom. 2012 Nov;47(11):1473-81
references.pmid: 23147824
references.citation: Rapid Commun Mass Spectrom. 2009 Sep;23(18):3023-7
references.pmid: 19685478
references.citation: J Mass Spectrom. 2010 Jun;45(6):635-42
references.pmid: 20527032
references.citation: J Am Soc Mass Spectrom. 2005 Feb;16(2):176-82
references.pmid: 15694768
references.citation: J Am Soc Mass Spectrom. 1999 Nov;10(11):1105-10
references.pmid: 10536817
references.citation: Anal Chem. 2004 Jul 15;76(14):3930-4
references.pmid: 15253626
references.citation: Anal Chem. 2004 May 1;76(9):2462-9
references.pmid: 15117184
references.citation: Anal Chem. 2000 Nov 1;72(21):5239-43
references.pmid: 11080870
references.citation: Rapid Commun Mass Spectrom. 2003;17(8):860-8
references.pmid: 12672142
references.citation: Anal Chem. 1997 Jul 1;69(13):2525-9
references.pmid: 9212711
references.citation: Anal Chem. 1988 Oct 15;60(20):2299-301
references.pmid: 3239801
references.citation: Rapid Commun Mass Spectrom. 2002;16(3):176-84
references.pmid: 11803538
references.citation: Anal Chem. 2002 Sep 1;74(17):468A-476A
references.pmid: 12236377
references.citation: Rapid Commun Mass Spectrom. 2011 Mar 30;25(6):815-20
references.pmid: 21337644
references.citation: J Am Soc Mass Spectrom. 2010 Feb;21(2):294-9
references.pmid: 19955002