Figure 2.
Activation of NE680 by NE and effect of sivelestat. (a) The agent (0.5 μM) was activated in vitro by a panel of enzymes (0.05 μM) in optimized buffers and pH for each enzyme and the fluorescence monitored up to 5 h in a fluorescence microplate reader. Released fluorescence was obtained by subtracting the fluorescence of NE680 agent only from that of the NE680 in the presence of enzymes. (b) Inhibition of human NE or PR3 by sivelestat. Reactions were carried out in the presence of varying concentrations of sivelestat. The IC50 represents the concentration of sivelestat needed to achieve 50% inhibition of NE680 activation.