Linking Protein Modifications to Functional Impact.
Protein modifications are critical for the efficacy, safety, and stability of therapeutic antibodies. Here, we introduce a comprehensive analysis platform tailored to assess post-translational modifications of therapeutic proteins hand in hand with their functional activity. In the present approach, we successfully applied peptide mapping with LC-ESI-MS to determine deamidation and oxidation of alkaline-stressed Etanercept. On functional level, the instaCELL TNF-α neutralization assay served as a state-of-the-art cell-based assay to assess the potency of Etanercept. With our holistic analysis platform, we observed increased deamidation accompanied by a loss of functional activity of Etanercept upon alkaline stress, making our approach a blueprint for future characterization studies of therapeutic antibodies.
