Applications using an alkylation method for Carboxy-terminal protein sequencing

In the biopharmaceutical industry, C-terminal sequence information can be essential for the early characterization of recombinant proteins, as well as for the routine batch analysis, and several automated chemical degradation schemes, analogous in principle to the Edman method for amino-terminal (N-terminal) sequencing, have been proposed. This chapter explores specific examples, wherein the application of chemistry, especially the Perkin-Elmer method can be used as an additional analytical tool for protein characterization. The chapter discusses the chemistry's robustness in confirming the expected sequence of recombinant proteins, and that this method can identify post-translational modifications and sample heterogeneity. The sequencing method has been demonstrated on proteins obtained from several independent laboratories, and the information obtained has been complimentary and consistent with data obtained from other analytical techniques, such as peptide mapping, amino acid analysis, and mass spectrometry. Although, some amino acid residues interfere with sequencing all protein samples, however, many proteins have been sequenced successfully by this new C-terminal sequencing method, which continues to improve, and thereby provides a useful analytical tool.