Are of the peptides termini modified in any way?
The peptides used in the Kinase Substrate Sets are N-terminally biotinylated and C-terminally amidated. The peptides used in the Phosphatase Substrate Sets are N-terminally free and C-terminally amidated. The peptides used in the Protease Substrate Sets carry Fluorophore and Quencher on N- and C-terminal ends respectively.