Development of Novel C-Terminal Sequencing Methods

Development of a reliable C-terminal sequencing method has been expected from various aspects including sequencing protein, analyzing posttranslational process, confirming recombinant proteins and cloning. Carboxypeptidase digestion has been commonly used with limitations. Since a classical isothiocyanate degradation was proposed, several modifications were reported in the past two conferences (Hawkes and Boyd, 1991; Inglis et al., 1991; Miller and Shively, 1989). The present paper summarizes two related novel carboxy-terminal sequencing methods using perfluorinated carboxylic acids in monohydrate form and carboxylic acid anhydrides. These reagents produce the mixtures of C-terminal successive degraded molecules which are able to be analyzed by fast-atom-bombardment (FAB)- or electrospray ionization (ESI)-mass spectrometry (MS).