Fig. 4

Residual activity of Il-DyP4 treated with increasing NBS concentrations for modification of Trp residues. Substrates: a Simple compounds, b Bulky dyes. The assay mixtures (1 mL) contained 1 mM of simple compounds or 25–200 μM of bulky dyes, 0.25 μg/mL (for simple compounds) or 0.5 μg/mL (for bulky dyes) of modified enzyme. The reaction was initiated by 0.1 mM H₂O₂ at 35 °C, pH 3.5. Samples without enzyme served as the control and the activity of untreated Il-DyP4 was taken as 100%