Mass spectrometry in the investigation of β-lysine-containing peptides

Mass spectrometry can be used for amino acid sequence determination in β-lysine-containing peptides and for the identification of α- and β-lysine residues in peptides, as well as for amide bond type determination in β-lysine peptides. The peptide bond in streptothricin D is shown to be formed through the participation of an ε-amino group of the L-β-lysine residue.