New Tricks to Sequence a Protein: Top-Down Mass Spectrometry and Biopharmaceutical Characterization

摘要

Proteins become increasingly important in drug development, prompting for their detailed analysis and side product characterization in development and QC. Mass spectrometric Top-Down sequencing (TDS) addresses the key requirement to assign N- and C-terminal sequences in biologics and biosimilars. The principles of the new technology are described and related to the classical Edman-sequencing approach. Numerous drugs used today are proteins (e.g., insulin or herceptin) and many more are in the development pipeline of the biopharmaceutical industry (1). They have to be characterized in terms of function, purity and structure with the same stringency as it has become standard for small molecular drugs (e.g., penicillin or aspirin) although this is much more difficult. This requires new technologies that help maintain drug safety even if the drug is, e.g., a large 150 kDa monoclonal therapeutic antibody, which is N-terminally pyroglutamylated, heterogeneously glycosylated and the C-terminal lysine residue at the heavy chain is removed.