ABSTRACT
The development of electrospray ionization (ESI) (1) and matrix-assisted laser desorption ionization (MALDI) (2) methods has allowed the vaporization and ionization of large biomolecules, thus providing the main analytical tool for determining proteins and other labile biomolecules. That, in turn, has opened the way to elucidate macromolecular structures and study their interactions with small molecules or other macromolecules, which are important aspects in understanding their biological function and developing new therapeutics. Most of these therapeutic macromolecules are produced now by recombinant DNA technology, which has allowed their production in large quantities in cell culture. For these biologically diverse and heterogeneous recombinant protein products, ESI and MALDI mass spectrometry (MS) can provide structural characterization, such as primary structure confirmation through relative molecular mass or molecular weight (Mr) determination, peptide mapping, and sequencing information, as described in many of the previous chapters.
