Mass spectrometry has already become an indispensable tool in the analytical armamentarium of the biopharmaceutical industry, although its current uses are limited to characterization of covalent structure of recombinant protein drugs. However, the scope of applications of mass spectrometry-based methods is beginning to expand to include characterization of the higher order structure and dynamics of biopharmaceutical products, a development which is catalyzed by the recent progress in mass spectrometry-based methods to study higher order protein structure. The two particularly promising methods that are likely to have the most significant and lasting impact in many areas of biopharmaceutical analysis, direct ESI MS and hydrogen/deuterium exchange, are focus of this article.
Keywords: Analytical characterization, biopharmaceuticals, charge state distribution, electrospray ionization, ion fragmentation, hydrogen/deuterium exchange, higher order structure protein, therapeutics, mass spectrometry, protein conformation, protein interaction, higher order protein structure, biopharmaceutical analysis, direct ESI MS, Analysis of Conformational Integrity of Biopharmaceutical Products