title: Structural identification of modified amino acids on the interface between EPO and its receptor from EPO BRP, human recombinant erythropoietin by LC/MS analysis.
abstract: Protein modifications of recombinant pharmaceuticals have been observed both in vitro and in vivo. These modifications may result in lower efficacy, as well as bioavailability changes and antigenicity among the protein pharmaceuticals. Therefore, the contents of modification should be monitored for the quality and efficacy of protein pharmaceuticals. The interface of EPO and its receptor was visualized, and potential amino acids interacting on the interface were also listed. Two different types of modifications on the interface were identified in the preparation of rHu-EPO BRP. A UPLC/Q-TOF MS method was used to evaluate the modification at those variants. The modification of the oxidized variant was localized on the Met54 and the deamidated variants were localized on the Asn47 and Asn147. The extent of oxidation at Met54 was 3.0% and those of deamidation at Asn47 and Asn147 were 2.9% and 4.8%, respectively.
authors.affiliation: Department of Stereoscopic Media, Korean German Institute of Technology, Korea Research Institute of Standards and Science, Korea ; BIOnSYSTEMS, Inc., R&D Center, Korea Research Institute of Standards and Science, Korea.
authors.forename: Kwang-Eun
authors.initials: KE
authors.lastname: Song
authors.affiliation: Department of Stereoscopic Media, Korean German Institute of Technology, Korea Research Institute of Standards and Science, Korea.
authors.forename: Jaehee
authors.initials: J
authors.lastname: Byeon
authors.affiliation: BIOnSYSTEMS, Inc., R&D Center, Korea Research Institute of Standards and Science, Korea.
authors.forename: Dae-Bong
authors.initials: DB
authors.lastname: Moon
authors.affiliation: Center for Bioanalysis, Korea Research Institute of Standards and Science, Korea.
authors.forename: Hyong-Ha
authors.initials: HH
authors.lastname: Kim
authors.affiliation: Department of Newmedia, Korean German Institute of Technology, Korea Research Institute of Standards and Science, Korea.
authors.forename: Yoo-Joo
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Department of Newmedia, Korean German Institute of Technology, Korea Research Institute of Standards and Science, Korea.
authors.forename: Jung-Keun
authors.initials: JK
authors.lastname: Suh
mesh_terms: D000596:Amino Acids / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D002853:Chromatography, Liquid; D003641:Deamination; D004921:Erythropoietin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014644:Genetic Variation; D006801:Humans; D013058:Mass Spectrometry; D008958:Models, Molecular; D010084:Oxidation-Reduction; D010449:Peptide Mapping / Q000379:methods*; D017467:Receptors, Erythropoietin / Q000737:chemistry* / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D000596:Amino Acids; D017467:Receptors, Erythropoietin; D011994:Recombinant Proteins; D004921:Erythropoietin
keywords: deamidation; erythropoietin; interface; modification; oxidation