CHEMBL5730607

KLK1 Activity Assay: Recombinant human tissue kallikrein (KLK1) was obtained from R&D Systems. Pro-Phe-Arg-AMC (I-1295) substrate was obtained from Bachem. KLK1 enzyme is activated by incubating 0.5 mg/ml KLK1 combined with 0.1 μg/ml thermolysin in a buffer of 0.05 M Tres (pH 7.5), 0.15 M NaCl, and 0.01 M CaCl2 for one hour at 37° C. The thermolysin is then deactivated by the addition of equal parts 20 mM 1, 10 phenanthroline solution in water. The activated KLK1 solution is then added to CHES buffer (0.05 M CHES, 0.15 M NaCl, 0.01 M CaCl2, pH 10) for a final concentration of 5 nM along with the test article and incubated for 10 minutes. Substrate is then added at a concentration of 2.75 μM. Substrate activation is read 10 minutes after substrate addition using a Synergy H1 multifunction plate reader (Biotek) programmed with a 360 nm excitation wavelength and a 480 nm emission wavelength. Inhibitor response was established by adding test compound as ten point, three-fold serial dilutions, as known in the art.