title: Structural characterization of chemically derivatized oligosaccharides by nanoflow electrospray ionization mass spectrometry.
abstract: Oligosaccharides released from several glycoproteins were derivatized with either 4-aminobenzoic acid 2-(diethylamino)ethyl ester (ABDEAE) (Yoshino, K.; et al. Anal. Chem. 1995, 67, 4028-4031) or 2-aminopyridine. The resulting derivatives were analyzed on a nanoflow electrospray ionization (ESI) quadrupole-inlet time-of-flight mass spectrometer using the low-energy collision-induced dissociation technique. In the MS/MS spectra, the oxonium (b or internal series) and y series ions, which are derived from the multiply charged precursor ions, were predominant and were used for the structural readout. Some oxonium ions that were observed in the low-mass region, but that were not found in the PSD analyses (Mo, W.; et al. Anal. Chem. 1998, 70, 4520-4526), rendered a more detailed structural insight. The oxonium ions at m/z 512.2, which are derived from the fucosylated oligosaccharides of immunoglobulin Y and thyroglobulin, were observed, suggesting that fucosylation had occurred proximal to the outer nonreducing terminus. In addition, the data herein show that structural elucidation can be routinely achieved at a low sample concentration. For the case of ABDEAE derivatives, this can be achieved at the 50 fmol/microL level and with the actual sample consumption at the attomole level using nanoflow ESI MS/MS.
authors.affiliation: Institute for Protein Research, Osaka University, Japan.
authors.forename: W
authors.initials: W
authors.lastname: Mo
authors.forename: H
authors.initials: H
authors.lastname: Sakamoto
authors.forename: A
authors.initials: A
authors.lastname: Nishikawa
authors.forename: N
authors.initials: N
authors.lastname: Kagi
authors.forename: J I
authors.initials: JI
authors.lastname: Langridge
authors.forename: Y
authors.initials: Y
authors.lastname: Shimonishi
authors.forename: T
authors.initials: T
authors.lastname: Takao
mesh_terms: D000631:Aminopyridines / Q000737:chemistry; D002240:Carbohydrate Sequence; D007136:Immunoglobulins / Q000032:analysis / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000032:analysis* / Q000737:chemistry; D011343:Procaine / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013954:Thyroglobulin / Q000032:analysis / Q000737:chemistry; D014168:Transferrin / Q000032:analysis / Q000737:chemistry
chemical_list: D000631:Aminopyridines; C016512:IgY; D007136:Immunoglobulins; D009844:Oligosaccharides; D014168:Transferrin; C016549:maltohexaose; D011343:Procaine; D013954:Thyroglobulin; C032439:alpha-aminopyridine