Recently, a novel recombinant human
erythropoietin (
epoetin delta, Dynepo) has been marketed in the European Union for the treatment of
chronic kidney disease,
cancer patients receiving
chemotherapy, and so forth.
Epoetin delta is engineered in cultures of the human
fibrosarcoma cell line HT-1080 by homologous recombination and "gene activation." Unlike recombinant erythropoietins produced in other mammalian cells,
epoetin delta is supposed to have a human-type glycosylation profile. However, the isoelectric focusing profile of
epoetin delta differs from that of endogenous
erythropoietin (both urinary and plasmatic). In this work, structural and quantitative analysis of the O- and N-
glycans of
epoetin delta was performed and compared with glycosylation from recombinant
erythropoietin produced in Chinese hamster ovary (CHO) cells. From the comparison, significant differences in the sialylation of O-
glycans were found. Furthermore, the N-
glycan analysis indicated a lower heterogeneity from
epoetin delta when compared with its CHO homologue, being predominantly tetraantennary without
N-acetyllactosamine repeats in the former. The
sialic acid characterization revealed the absence of
N-glycolylneuraminic acid. The overall
sugar profiles of both
glycoproteins appeared to be significantly different and could be useful for maintaining
pharmaceutical quality control, detecting the misuse of
erythropoietin in sports, and establishing new avenues to link glycosylation with
biological activity of
glycoproteins.