CHEMBL3887323

Inhibition Assay: Recombinant human cathepsin A (residues 29-480, with a C-terminal 10-His tag; R&D Systems, #1049-SE) was proteolytically activated with recombinant human cathepsin L (R&D Systems, #952-CY). Briefly, cathepsin A was incubated at 10 ug/ml with cathepsin L at 1 ug/ml in activation buffer (25 mM 2-(morpholin-4-yl)-ethanesulfonic acid (MES), pH 6.0, containing 5 mM dithiothreitol (DTT)) for 15 min at 37° C. Cathepsin L activity was then stopped by the addition of the cysteine protease inhibitor E-64 (N-(trans-epoxysuccinyl)-L-leucine-4-guanidinobutylamide; Sigma-Aldrich, # E3132; dissolved in activation buffer/DMSO) to a final concentration of 10 uM.The activated cathepsin A was diluted in assay buffer (25 mM MES, pH 5.5, containing 5 mM DTT) and mixed with the test compound (dissolved in assay buffer containing (v/v) 3% DMSO) or, in the control experiments, with the vehicle in a multiple assay plate. After incubation for 15 min at room temperature.