CHEMBL5736344

Enzymatic Assay for In Vitro Evaluation of PSMA Inhibitors: The inhibitory activity of all compounds was determined using a fluorescent assay of human PSMA activity. The enzyme used in the assay was purchased from R&D Systems and stored at −80° C. The PSMA activity was assayed in a two-step process. In the first step, aliquots of enzyme (0.2 μg/mL) were incubated for 1 h at 37° C. in 50 mM HEPES, 0.1 M NaCl, pH 7.5, in the presence of 20 μM NAAG and the given inhibitor, in a volume of 250 μL, to allow for the accumulation of glutamate produced in the PSMA reaction. In the second step, the amount of accumulated glutamate was measured using the OPA reaction, and the fluorescence was read with a SpectraMax fluorescent plate reader using excitation at 330 nm and emission at 450 nm. The final Ki values for each inhibitor were calculated from the respective IC50 values using the Cheng and Prusoff equation.