Figure 1. NAAG peptidase (GCPII) inhibition assay.
NAAG radiolabeled in the glutamate moiety was hydrolyzed by membranes of CHO cells that had been stably transfected with GCPII. The release of [3H]-glutamate from [3H]-NAAG in the absence of any inhibitor is taken as 100% enzyme activity. The inhibitory efficacy of ZJ-43, PGI-02749 and PGI-02776 were determined over a range concentrations from 1 nM to 100 uM. The data demonstrate that the parent compound (ZJ-43) strongly inhibits GCPII while the mono-ester (PGI-02749) and the di-ester (PGI-02776) weakly inhibit GCPII. * p<0.05; ** p<0.01; *** p<0.001 compared to the no inhibitor control.