Assay Method Information

Assay Name:  In Vitro Enzyme Inhibition
Description:  A 10 mM solution of the test compound was made in DMSO. This solution was serially diluted 1:5 in DMSO to yield 2000, 400, 80, 16, 3.2, 0.64, 0.128, 0.0256 and 0.00512 μM compound test solutions. A control tube containing only DMSO is included. 16 μL of each compound test solution was combined with 384 μL of assay buffer (50 mM Tris-HCl pH 7.5, 150 mM NaCl, 0.01% Triton X-100) to yield a 4× test compound buffer stock .Separately, a 40 nM solution of human Plasma Kallikrein (Abcam) and a 93.6 μM solution Pro-Phe-Arg-AMC (Bachem) were made using assay buffer. These solutions are hereby referred to as 4×hPK and 2×PFR-AMC, respectively.60 μL of each 4× test compound buffer stock was combined with 60 μL of 4×hPK to yield 120 μL of 2× test compound buffer stock/2×hPK . 50 μL was removed from this mixture and placed into duplicate wells on a Microfluor 1Black U-bottom microtiter plate (Thermo Scientific). This plate was incubated for 5 minutes at 37° C. To each well, 50 L of pre-warmed 2×PFR-AMC was added to start the enzymatic reaction. Cleavage of PFR-AMC was monitored in a Biotek Synergy H4 reader set at 37° C. Readings are taken every 43 seconds for 1 hour. The highest mean velocity over 20 reads ( 15 minutes) is used to calculate the IC50. The IC50 is calculated using the Gen5 (Biotek Instruments).
Affinity data for this assay
 

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