MONITORING THE GLYCOSYLATION PATTERN OF RECOMBINANT INTERFERON-OMEGA WITH HIGH-PH ANION-EXCHANGE CHROMATOGRAPHY AND CAPILLARY ELECTROPHORESIS

The enzymatic glycosylation of certain asparagine residues in the prot ein structure has a profound influence on their physico-chemical prope rties. Many recombinant DNA derived glycoprotein pharmaceuticals for t herapeutic use are glycosylated. Their oligosaccharides are important with regard to stability, solubility, in vivo activity and antigenicit y. Sophisticated analytical methods that allow a high resolution of sy nthesized carbohydrate structures are therefore necessary to ensure a constant product quality. To elucidate the robustness of interferon-om ega glycosylation regarding process modifications, Chinese Hamster Ova ry (CHO)-cells expressing human interferon-omega were cultivated under different fermentation conditions. The most significant glycosylation alterations resulted from the varied parameters such as initial ammon ia concentration in the production medium, cultivation mode (adherent versus suspended) or process time. These are detectable with HPAEC (hi gh-pH anion-exchange chromatography) oligosaccharide mapping as well a s with capillary electrophoresis.