Figure 3

Dose-response curves for the inhibition of human mast-cell tryptase by A pure benzamidine (K_C = I₅₀ = 50 µM) or B benzamidine doped with 0.02% of the tight binding inhibitor CRA-001390 (K_T = 0.065 nM). Data points are averages from triplicate measurements of initial velocities. Percent inhibition values (p) were fitted to the four-parameter logistic equation (1) to obtain I₅₀ values. Equation (6) predicts for "adulterated'' benzamidine I₅₀ = 0.40 µM.