Rapid Online Reduction and Characterization of Protein Modifications Using Fully Automated Two-Dimensional High Performance Liquid Chromatography–Mass Spectrometry
Characterization of protein modifications is an essential aspect of biopharmaceutical development. Traditionally, the characterization process of chromatographic peaks involves manual, larger-scale fractionation to obtain a sufficient amount of material for further analytical studies. This article presents a fully automated process for online peak fractionation and reduction of therapeutic antibodies with subsequent quadrupole time-of-flight mass spectrometry (QTOF-MS) characterization. This innovative technique significantly accelerates MS peak characterization compared to traditional approaches and avoids the risk of unintended modifications of the variants as a result of the isolation process, for example, deamidation during storage of isoforms. This approach considerably reduces the required sample amount and can be used for the characterization of product-related impurities during early stage development.