CHEMBL5731334

Assay for Determination of Ki Values for Inhibition of GCase Activity: Various concentrations of test compounds were prepared in DMSO and then diluted into buffer consisting of 50 mM sodium phosphate 0.25% w/v sodium taurodexoycholate, pH 7.0. GCase enzyme (Cerezyme®, recombinant human GCase obtained from R&D Systems) was diluted in the same buffer to 0.143 nM. The reaction solution consisted of 25 μL of 6 mM 4-methylumbelliferone-β-D glucopyranoside in 10% DMSO in the same buffer, 12.5 μL of enzyme and 12.5 μL of various concentrations of test compound diluted in buffer. The final concentrations in the reaction were 0.036 nM GCase, 3 mM 4-methylumbelliferone-β-D glucopyranoside, and various concentrations of inhibitor. The reaction was initiated by addition of enzyme and allowed to proceed for 20 min at 37° C. to assess GCase activity. Reactions were stopped by the addition of an equal volume (50 μL) of 0.5 M NaOH, 0.3 M glycine, pH 10.5. Fluorescence was measured on a Biotek Synergy H4 plate reader using a setting of 10 measurements per data point at wavelengths of 365 nm for excitation and 450 nm for emission. Incubations without added enzyme or added inhibitors were used to define no enzyme activity and maximal enzyme activity, respectively. IC50 values were determined by fitting the data to a log[inhibitor concentration] versus response curve using GraphPad Prism. IC50 values were calculated as the concentration of inhibitor required to inhibit GCase activity by 50%. Ki values were determined from the IC50 values by employing the Cheng-Prusoff equation using a GCase Km of 7.9 mM for 4-methylumbelliferone-β-D glucopyranoside at pH 7.0. The compounds of the invention tested exhibit Ki values for inhibition of GCase in the range 0.1 nM-50 μM.