N-Me-pAB-Glu-γ-Glu-γ-Tyr(3-NO2): an internally quenched fluorogenic γ-glutamyl hydrolase substrate

A γ-glutamyl tripeptide containing an internally quenched fluorophore has been synthesized and shown to be a substrate for recombinant rat γ-glutamyl hydrolase. HPLC, LC–MS, and fluorescence spectra support the conclusion that selective hydrolysis occurs at the penultimate peptide bond. Preliminary data indicate that hydrolysis of this substrate can be monitored continuously to yield steady-state kinetic data