Fig. 3

Enzyme activity of yCsCB. a Enzyme activity of yCsCBs was assayed by using two fluorescent substrates (Z-Phe-Arg-AMC and Z-Arg-Arg-AMC) under different enzyme concentrations (0, 0.3125, 0.625, 1.25, 2.5, 5, 10 and 20 μM). b Enzyme activity of yCsCBs was assayed by using fluorescent Z-Phe-Arg-AMC as a substrate under different pH values (3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5 and 8.0). c Enzyme activity of yCsCBs was assayed by using fluorescent Z-Phe-Arg-AMC as substrate under different temperatures (0, 4, 16, 28, 37, 42 and 55 °C). Fluorescent intensity was measured at 348 nm to calculate relative enzyme activity