Effect of pH and temperature on the protease activity The optimal pH and temperature of cordysobin were measured by using Suc-Leu-Leu-Val-Tyr-MCA as substrate. For the pH assay, the activity of cordysobin was determined at the temperature of 37°C for 10 min at a pH range of 4.0–12.0 using a wide range pH buffer (6.008 g citric acid, 3.893 g KH2PO4, 1.769 g boric acid, and 5.266 g barbituric acid dissolved in 1000 ml of distilled water. The pH of the reaction buffer was adjusted to range from pH 4.0 to 12.0 using 0.2 M NaOH). For the temperature profile study, the activity was assayed at a temperature range between 20°C and 90°C using 10 mM Tris– HCl buffer (pH 8.0).