Exploring New Proteome Space: Combining Lys-N Proteolytic Digestion and Strong Cation Exchange (SCX) Separation in Peptide-Centric MS-Driven Proteomics
The current advances in mass spectrometry technology have led to the possibility of analyzing more complex biological samples such as entire proteomes. Here, we describe a new and powerful methodology that combines the use of the metalloendopeptidase Lys-N and strong cation exchange with mass spectrometric analysis. The approach described here allows one to separate peptides with different functional groups. The peptides we are able to isolate are N-terminal peptides, phosphorylated peptides with a single lysine, peptides with a single basic residue (lysine), and peptides with multiply basic residues. When this separation strategy is combined with tandem mass spectrometry that involves both collision-induced dissociation and electron transfer dissociation, one can achieve an optimal targeted strategy for proteome analysis.
Key wordsStrong cation exchange (SCX) Lys-N mass spectrometry tandem mass spectrometry electron transfer dissociation