Research Article

Digestive Alkaline Proteases from Zosterisessor ophiocephalus, Raja clavata, and Scorpaena scrofa: Characteristics and Application in Chitin Extraction

Figure 2

Effect of pH on activity (a) and stability (b) of alkaline crude protease extracts. The protease activity was assayed in the pH range 5.0–13.0 using buffers of different pH values at 50°C. The maximum activity of each crude enzyme extract was considered as 100%. The pH stability was determined by incubating the crude enzymes in different buffers for 1 hour at 4°C and the residual activities were measured at the optimum conditions of each enzyme preparation. The activity of the enzyme before incubation was taken as 100%. Buffer solutions used for pH activity and stability are presented in Section 2. Values are means of three independent experiments.