“It was shown to act as a time-dependent competitive inhibitor, and the inhibition constants for the binding of Nafamostat to trypsin (i.e., Ki) and the overall inhibition constants (i.e., Ki*) were calculated to be 11.5 microM and 0.4+/-0.14 nM, respectively.”
“The product of the deacylation step, 4-guanidinobenzoic acid, showed … concentration of 200 microM. These data strongly suggest that while Nafamostat … trypsin , it is actually an extremely poor substrate, and that apparent inhibition is due to … a very stable acyl-enzyme intermediate, analogous to some other active site titrants.”