Fig. 2. Enzymatic activity of the purified and activated rFgCatB2. (A) Lane 1: Non-reducing gelatin substrate SDS–PAGE (12.5%) of rFgCatB2 shows gelatinolytic activity at 37–
38 kDa and 50–90 kDa; lane 2: Coomassie-stained proteins corresponded with proteins shown in lane 1. The molecular weight markers are shown on the left side. (B) Activity
of FgCatB2 determined by incubating synthetic fluorometric substrate Z-Phe-Arg-AMC with the activated rFgCatB2 for 30 min. Direct correlation could be observed between
fluorescence units and time of incubation. (C, D) Cleavage of natural substrates, calf skin type I collagen and human IgG by the rFgCatB2: Lane 1: Substrate alone; Lane 2:
Substrate co-incubated with activation buffer; Lanes 3–7: Substrate co-incubated with activated rFgCatB2 for 0, 10, 30, 60 and 120 min, respectively; Lane 8; rFgCatB2 was
incubated with E-64 inhibitor for 30 min prior to addition of the substrate that was co-incubated for more than 120 min.