Electrospray Differential Mobility Analysis as an Orthogonal Tool to Size Exclusion Chromatography for Characterization of Protein Aggregates
Suvajyoti S. Guha, Joshua R. Wayment, Michael J. Tarlov, Michael R. Zachariah
The biopharmaceutical industry characterizes and quantifies aggregation of protein therapeutics using multiple analytical techniques to cross validate results. Here we demonstrate the use of electrospray-differential mobility analysis (ES-DMA), a gas-phase and atmospheric pressure ion-mobility method for characterizing protein aggregates. Two immunoglobulins (IgGs) are systematically heat treated to induce aggregation and characterized using size exclusion chromatography (SEC) and ES-DMA. Although ES-DMA is a gas phase characterization method, we find that aggregation kinetic rate constants determined by ES-DMA to be in excellent agreement with those determined by SEC. It is also found that ES-DMA is more capable of resolving aggregates of IgGs than SEC. The higher resolution of ES-DMA and a limit of detection two orders of magnitude lower than the SEC potentially make it a powerful tool for characterization of nascent protein aggregates in the biopharmaceutical industry.