Fig. 3.

Effect of pH and temperature (filled square 0.5 h, filled triangle 3 h, filled circle 12 h). a The optimum pH of the purified enzyme was determined by measuring the activity over the pH range of 3.0–11.0 (pH 3.0, 20 mM citrate buffer; pH 4.0–5.0, 50 mM acetate buffer; pH 6.0–7.0, 30 mM phosphate buffer; pH 8.0, 50 mM tris buffer; pH 9.0–11.0, 30 mM sodium carbonate/sodium bicarbonate buffer) at 45 °C; b The optimal temperature of the fibrinolytic enzyme was determined by measuring activity over the temperature range of 20–70 °C at pH 10.5; c The pH stability was determined by measuring the residual enzymatic activity after 0.5, 3, and 12 h incubation of the purified enzyme in various buffers over the pH range of 3.0–13.0 (pH 12.0–13.0 buffer, 100 mM glycine–NaOH) at 45 °C; d The temperature stability was determined by measuring the residual enzymatic activity after 0.5, 3, and 12 h incubation of the purified enzyme over the temperature range of 20–70 °C at the buffer of pH 10.5