Figure 2.

Hydrolytic collagenase activity of ST-SOT towards various substrates. (A) Uninduced or induced (2% L-arabinose) ST-SOT was incubated on LB-gelatin plates overnight (16 h) at 37 °C. Hydrolysis of gelatin in LB agar media is observed as opaque areas on LB-gelatin plates. Arrows indicate areas where uninduced or induced ST-SOT were spotted onto the plate. (B) Hydrolysis reactions were performed using uninduced or induced ST-SOT co-incubated with FITC-conjugated pig skin gelatin, bovine skin collagen type I (C) or human placenta collagen type IV (D) in 50 mM Tris-HCl (pH 8.0) containing 10 mM CaCl₂ at 37 °C. Enzyme activity was measured by monitoring fluorescence (FITC) (ex: 495 nm, em: 519 nm). Data are expressed as mean ± error of mean of three independent experiments. * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001, t-test.