title: Application of electrospray ionization MS/MS and matrix-assisted laser desorption/ionization-time of flight mass spectrometry to structural analysis of the glycosyl-phosphatidylinositol-anchored protein.
abstract: We applied the improved sensitivity and soft ionization characteristics of electrospray Ionization (ESI)-MS/MS and matrix-assisted laser desorption/ionization(MALDI)-time of flight (TOF) mass spectrometry (MS) to analysis of the GPI-anchored C-terminal peptide derived from 5'-nucleotidase. ESI-MS/MS analysis was applied to the core structure (MW, 2,743). In the collision-induced dissociation (CID) spectrum, single-charged ions such as m/z 162 (glucosamine), 286 (mannose-phosphate-ethanolamine), and 447 ([mannose-phosphate-ethanolamine]-glucosamine) were clearly detected as characteristic fragment ions of the GPI-anchored peptide. On MALDI-TOF-MS analysis, heterogeneous peaks of GPI-anchored peptides were detected as single-charged ions in the positive mode. Product ions were obtained by post-source decay (PSD) of m/z 2,905 using curved field reflectron of TOF-MS. Most of the expected product ions derived from the GPI-anchored peptide, containing the core structure and an additional mannose side chain, were successively obtained. Thus, ESI-MS/MS and MALDI-TOF-PSD-MS proved to be effective and sensitive methods for analyzing the GPI-anchored peptide structure with less than 10 pmol of sample. These characteristic fragments or fragmentation patterns seem to be very useful for identification of GPI-anchored C-terminal peptides derived from any kind of GPI-anchored protein.
authors.affiliation: Faculty of Pharmaceutical Sciences, Nagoya City University, Mizuho-ku, Nagoya, Aichi, 467-0027, Japan. taguchi@phar.nagoya-cu.ac.jp
authors.forename: R
authors.initials: R
authors.lastname: Taguchi
authors.forename: N
authors.initials: N
authors.lastname: Hamakawa
authors.forename: N
authors.initials: N
authors.lastname: Maekawa
authors.forename: H
authors.initials: H
authors.lastname: Ikezawa
mesh_terms: D015720:5'-Nucleotidase / Q000737:chemistry; D000595:Amino Acid Sequence; D000818:Animals; D001412:Bacillus subtilis / Q000201:enzymology; D002417:Cattle; D017261:Glycosylphosphatidylinositols / Q000737:chemistry*; D008099:Liver / Q000201:enzymology; D013058:Mass Spectrometry / Q000379:methods*; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D011499:Protein Processing, Post-Translational; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D010738:Type C Phospholipases / Q000737:chemistry
chemical_list: D017261:Glycosylphosphatidylinositols; D010455:Peptides; D015720:5'-Nucleotidase; D010738:Type C Phospholipases