Edman degradation and MALDI sequencing enables N- and C-terminal sequence analysis of peptides

Abstract

Publisher Summary This chapter describes the combined use of automated Edman sequencing and MALDI sequencing for the determination of proteolytic peptide fragments in the low picomole range. Automated Edman degradation or MALDI sequencing can in principle yield the complete sequence of peptides. However, the amounts of peptide for sequencing in demanding biological problems are very low. The chapter suggests that both methods need to be operated at their highest performance possible and inherent limitations must be considered. A combined application of both methods is feasible, because of the very low sample consumption for MALDI MS. The example ambiguous sequence calls described in the chapter can be clarified by the complementary information. The application on proteolytic peptide fragments results often in metastable ions from the C-terminal part. In this way, the N-terminal sequence is achieved by Edman degradation, the molecular weight determines the overall size of the fragment, and ambiguous amino acid residues are identified by MALDI sequencing.