Erythropoietin (EPO) is a glycoprotein with three N-glycosylation sites and one O-glycosylation sites. According to the reference, all of the N-glyco-chains were acid complex type. The amount of sialic acid in rhEPO was determined and two N-glycosylation sites on it were confirmed by matrix-assisted laser desorption time of flight-time of flight mass spectrometry (MALDI-TOF-TOFMS) in this paper. The total amount of sialic acid in rhEPO accounts for 12.97%. Two N-glycosylation sites (Asn38,Asn83) were identified successfully.
Peptides were separated by reverse phase liquid chromatography (RPLC) from tryptic digest of myoglohin and sequenced by matrix-assisted laser desorption time of flight-time of flight mass spectrometry (MALDI-TOF-TOFMS). The result showed the sequence coverage of myoglobin is up to 79.7%.
