Fig. 4From: High level expression and biochemical characterization of an alkaline serine protease from Geobacillus stearothermophilus to prepare antihypertensive whey protein hydrolysateOptimal pH (a), pH stability (b), optimal temperature (c), and thermostability (d) of GsProS8. The influence of pH on GsProS8 activity was measured in 0.05 mol/L of different buffers at 40 °C. For the optimal pH, the relative activity (%) was determined against the specific activity of 3916 U/mg. To determine pH stability against the optimal activity (2631 U/mg, defined as 100% relative activity), GsProS8 was incubated in various buffers (0.05 mol/L) at 40 °C for 30 min. For optimal temperature, GsProS8 activity was tested at different temperatures in MOPS buffer (0.05 mol/L, at pH 8.5) in contrast to the specific activity of 3916 U/mg. The thermostability of GsProS8 was assayed against the optimal activity (3915 U/mg, defined as 100% relative activity) after incubation at different temperatures for 30 minBack to article page