Fig 2. Comparison of inhibitor potencies.

Data are expressed as percentage of activity relative to no-inhibitor control activity versus log₁₀ ratios of inhibitor to protease concentration. The proteases tested are human airway trypsin-like protease (HAT), matriptase, prostasin and β-tryptase. The dashed vertical line marks the inhibitor/enzyme ratio at which 50% inhibition is predicted for inactivation with 1:1 stoichiometry. Aprotinin achieves near-stoichiometric inhibition of prostasin and matriptase, whereas nafamostat achieves near-stoichiometric inhibition of tryptase and matriptase. N = 3–4; error bars show ± S.D.