title: Simultaneous analysis of 2-aminopyridine-derivatized neutral and sialylated oligosaccharides from human serum in the negative-ion mode by sonic spray ionization ion trap mass spectrometry.
abstract: Neutral and acidic (sialylated) 2-aminopyridine-derivatized (PA) oligosaccharides were analyzed by using reversed-phase high-performance liquid chromatography/ion trap mass spectrometry (RP-HPLC/IT MS) with a sonic spray ionization (SSI) source. Under the RP-HPLC separation using a buffer of 1 mM ammonium acetate (pH4.3) at a flow rate of 0.2 mL/min, both PA-oligosaccharides in the negative-ion mode showed a comparable degree of ionization efficiency, differing from that of the positive-ion mode, which exhibits a wide gap between their ionization efficiencies. In addition, the ion intensities of both PA-oligosaccharides were higher in the negative-ion mode than in the positive-ion mode. These results strongly suggest that the negative-ion mode of SSI-MS is suitable for simultaneous analysis of neutral and acidic (sialylated) oligosaccharides in RP-HPLC/MS. In the present study, RP-HPLC/SSI-IT MS in the negative-ion mode was used in the analysis of PA-oligosaccharides from human serum and its usefulness was investigated. As a result, 32 neutral and sialylated PA-oligosaccharides from human serum were identified with differentiating isomeric oligosaccharides and relatively quantified by a single HPLC/MS run. This method is useful for simple and rapid analysis of the overall distribution of neutral and sialylated oligosaccharides in a complex sample such as serum.
authors.affiliation: Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo 001-0021, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takegawa
authors.forename: Kisaburo
authors.initials: K
authors.lastname: Deguchi
authors.forename: Shinya
authors.initials: S
authors.lastname: Ito
authors.forename: Shinji
authors.initials: S
authors.lastname: Yoshioka
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nakagawa
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Nishimura
mesh_terms: D000631:Aminopyridines / Q000737:chemistry*; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006801:Humans; D007477:Ions; D013058:Mass Spectrometry / Q000379:methods*; D008969:Molecular Sequence Data; D019158:N-Acetylneuraminic Acid / Q000737:chemistry; D009844:Oligosaccharides / Q000097:blood* / Q000737:chemistry*; D012680:Sensitivity and Specificity
chemical_list: D000631:Aminopyridines; D007477:Ions; D009844:Oligosaccharides; D019158:N-Acetylneuraminic Acid; C032439:alpha-aminopyridine