Fig. 5

Inhibition effect on enzyme activity of yCsCBs. a-d yCsCB1, yCsCB2, yCsCB3 and yCsCB4, respectively. yCsCBs (20 μM) were pre-incubated with or without protease inhibitors including E-64 (20 μM), iodoacetic acid (10 μM), PMSF (2 mM), EDTA (2 mM), AEBSF (200 μM), TPCK (200 μM) and CA-074 methyl ester (1 μM). Z-Phe-Arg-AMC (20 μM) was added to the reactions after 30 min and incubated for another 1 h. Fluorescent intensity was measured at 348 nm to calculate relative enzyme activity. Errors represent data from triplicate samples