title: Structural Identification of a Non-Glycosylated Variant at Ser126 for O-Glycosylation Site from EPO BRP, Human Recombinant Erythropoietin by LC/MS Analysis.
abstract: A variant peak was detected in the analysis of RP-HPLC of rHu-EPO, which has about 7% relative content. Fractions of the main and the variant peaks were pooled separately and further analyzed to identify the molecular structure of the variant peak. Total mass analysis for each peak fraction using ESI-TOF MS shows differences in molecular mass. The fraction of the main peak tends to result in higher molecular masses than the fraction of the variant. The detected masses for the variant are about 600-1000 Da smaller than those for the main peak. Peptide mapping analysis for each peak fraction using Asp-N and Glu-C shows differences in O-glycopeptide profiles at Ser126. The O-glycopeptides were not detected in the fraction of the variant. It is concluded that the variant peak is non-O-glycosylated rHu-EPO and the main peak is fully O-glycosylated rHu-EPO at Ser126.
authors.affiliation: Deptatment of Stereoscopic Media, Korean German Institute of Technology, Seoul 157-930, Korea.
authors.forename: Jaehee
authors.initials: J
authors.lastname: Byeon
authors.affiliation: BIOnSYSTEMS, Inc., R&D Center, Incheon 406-840, Korea.
authors.forename: Yu-Ri
authors.initials: YR
authors.lastname: Lim
authors.affiliation: Center for Bioanalysis, Korea Research Institute of Standards and Science, Daejeon 305-340, Korea.
authors.forename: Hyong-Ha
authors.initials: HH
authors.lastname: Kim
authors.affiliation: Deptatment of Stereoscopic Media, Korean German Institute of Technology, Seoul 157-930, Korea.|Department of Newmedia, Korean German Institute of Technology, Seoul 157-930, Korea.
authors.forename: Jung-Keun
authors.initials: JK
authors.lastname: Suh
mesh_terms: D002853:Chromatography, Liquid; D004921:Erythropoietin / Q000737:chemistry* / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D013058:Mass Spectrometry; D010449:Peptide Mapping / Q000379:methods; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D011994:Recombinant Proteins; D004921:Erythropoietin
keywords: O-glycosylation; Peptide Mapping; erythropoietin; total mass analysis