Characterization of protein therapeutics by mass spectrometry: recent developments and future directions.

Mass spectrometry (MS) has become a powerful technology in the discovery and development of protein therapeutics in the biopharmaceutical industry. This review article describes recent developments and future trends in the characterization of protein therapeutics using MS. We discuss top-down MS for the characterization of protein modifications, hydrogen/deuterium exchange MS and ion mobility MS methods for higher order protein structure studies. Quantitative analysis of protein therapeutics (in vivo) by MS as an orthogonal approach to immunoassay for pharmacokinetics studies will also be illustrated.