High-Resolution Quantitative Characterization of Intact Biopharmaceuticals and Their Proteoforms
May 25, 2016
Proteins of biopharmaceutical interest are generally heterogeneous mixtures of proteoforms comprised of modifications. Accurate knowledge of the proteoform profile is critical for assessing the safety and stability of the drug. Current methods of analyzing post-translational modifications (PTMs) and glycan structures require proteolysis or glycan profiling that can result in lost information on correlated PTMs. Sample handling can also introduce artifacts and therefore, minimal sample preparation is desirable. Top-down mass spectrometry (MS) analysis of highly heterogeneous biopharmaceuticals is challenging due to the limited ability of current separation techniques in resolving proteoforms with small structural changes. In this work, we describe the top-down analysis of interferon-β1 (Avonex) in detail and preliminary data on middle-down (reduced) and intact mAbs.