title: MALDI-TOF-MS analysis of sialylated glycans and glycopeptides using 4-chloro-α-cyanocinnamic acid matrix.
abstract: For MALDI analysis of glycans and glycopeptides, the choice of matrix is crucial in minimizing desialylation by mass spectrometric in-source and metastable decay. Here, we evaluated the potential of 4-chloro-α-cyanocinnamic acid (Cl-CCA) for MALDI-TOF-MS analysis of labile sialylated tryptic N-glycopeptides and released N- and O-glycans. Similar to DHB, but in contrast to CHCA, the Cl-CCA matrix allowed the analysis of sialylated N-glycans and glycopeptides in negative ion mode MALDI-TOF-MS. Dried droplet preparations of Cl-CCA provided microcrystals with a homogeneous spatial distribution and high shot-to-shot repeatability similar to CHCA, which simplified the automatic measurement and improved the resolution and mass accuracy. Interestingly, reflectron-positive ion mode analysis of 1-phenyl-3-methyl-5-pyrazolone (PMP)-labeled O-glycans with Cl-CCA revealed more complete profiles than with DHB and CHCA. In conclusion, we clearly demonstrate the high potential of this rationally designed matrix for glycomics and glycoproteomics.
authors.affiliation: Biomolecular Mass Spectrometry Unit, Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands. m.h.j.selman@lumc.nl
authors.forename: Maurice H J
authors.initials: MH
authors.lastname: Selman
authors.forename: Marcus
authors.initials: M
authors.lastname: Hoffmann
authors.forename: Gerhild
authors.initials: G
authors.lastname: Zauner
authors.forename: Liam A
authors.initials: LA
authors.lastname: McDonnell
authors.forename: Crina I A
authors.initials: CI
authors.lastname: Balog
authors.forename: Erdmann
authors.initials: E
authors.lastname: Rapp
authors.forename: André M
authors.initials: AM
authors.lastname: Deelder
authors.forename: Manfred
authors.initials: M
authors.lastname: Wuhrer
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002240:Carbohydrate Sequence; D002417:Cattle; D002934:Cinnamates / Q000737:chemistry*; D006020:Glycopeptides / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D057230:Limit of Detection; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D011134:Polysaccharides / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D040901:Proteomics / Q000379:methods; D015203:Reproducibility of Results; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D014357:Trypsin / Q000378:metabolism
chemical_list: C532442:4-chloro-alpha-cyanocinnamic acid; D002934:Cinnamates; D006020:Glycopeptides; D007074:Immunoglobulin G; D010446:Peptide Fragments; D011134:Polysaccharides; D014357:Trypsin