Targeted Shifting of Protein Glycosylation Profiles in Mammalian Cell Culture through Media Supplementation of Cobalt

Protein glycosylation has had a long storied history towards impacting various structural, functional, and physiochemical properties of the proteins they are attached to. This important and often critical post-translational modification is thus monitored closely during the manufacturing of recombinant proteins, especially those destined for clinical use where the levels are often required to be maintained within an acceptable historically-proven range. In the present work, we highlight a systematic study towards the selective use of cobalt for the targeted shifting of protein glycosylation profiles on recombinant proteins through cell culture media supplementation. Cobalt was found to considerably increase the percentage of galactosylated N-glycan species, and thus support an increase in the overall extent of terminal protein glycosylation. These aforementioned results were found to be reproducible across different cell lines expressing different proteins, and cultured at different scales. Through the selective supplementation of cobalt, the targeted shifting of protein glycosylation profiles is demonstrated, as well as a potential means for ensuring biologic comparability.