Highly sensitive peptide-based probes for protein tyrosine phosphatase activity utilizing a fluorogenic mimic of phosphotyrosine.

Fluorescent probes that can be incorporated into peptides and proteins are in high demand, with applications ranging from cellular imaging to binding and activity assays. Here, we report the high yielding synthesis of an enantiomerically pure phosphocoumarin-based amino acid and its incorporation into peptides via standard solid-phase peptide synthesis methodologies. Peptides containing this new amino acid serve as highly sensitive fluorogenic probes for protein tyrosine phosphatase activity.