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