title: Profiling of N- and O-glycopeptides of erythropoietin by capillary zwitterionic type of hydrophilic interaction chromatography/electrospray ionization mass spectrometry.
abstract: Capillary zwitterionic-type hydrophilic interaction chromatography (ZIC-HILIC)/ESI-MS has been applied to the Glu-C digest of recombinant human erythropoietin (rhEPO) expressed in Chinese hamster ovary (CHO) cells. N-Glycopeptides (105) and O-glycopeptides (8) were detected in a single run of the capillary ZIC-HILIC/ESI-MS analysis. Among them, N-acetyl-neuraminic acids (Neu5Ac) of N- and O-glycans were partially acetylated and some were replaced with N-glycoyl-neuraminic acid (Neu5Gc). Their retentions in the ZIC-HILIC separation can be explained to some extent with the degree of acetylation and N-glycoylation, both of which influence the hydrophilicity/hydrophobicity of the N- and O-glycan moieties of glycopeptides.
authors.affiliation: Graduate School of Advanced Life Science, Hokkaido University, Sapporo, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takegawa
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ito
authors.forename: Takuro
authors.initials: T
authors.lastname: Keira
authors.forename: Kisaburo
authors.initials: K
authors.lastname: Deguchi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nakagawa
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Nishimura
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002853:Chromatography, Liquid / Q000379:methods*; D006224:Cricetinae; D003412:Cricetulus; D004563:Electrochemistry; D004921:Erythropoietin / Q000737:chemistry* / Q000235:genetics; D006020:Glycopeptides / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D006031:Glycosylation; D006801:Humans; D008969:Molecular Sequence Data; D015394:Molecular Structure; D011994:Recombinant Proteins; D012697:Serine Endopeptidases; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D006020:Glycopeptides; D011994:Recombinant Proteins; D004921:Erythropoietin; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase