Chymotrypsin activity extracted from beluga (Huso huso) intestine under some physical and chemical factors

In the present study, the physical and chemical factors including optimum temperature and pH, the effect of inhibitors, metal ions, oxidizing agents, and surfactants were assayed on the chymotrypsin activity from beluga (Huso huso) intestine. According to the obtained results, the optimum temperature and pH of the chymotrypsin were recorded at 50°C and 8, respectively, and its activity was extremely decreased at temperature>50°C. Inhibitors including SBTI, TLCK, PMSF, ρ-aminobenzamidine, TPCK, pepstatin A, iodoacetic acid and EDTA significantly inhibited the enzyme activity that PMSF, SBTI and TPCK had a completely inhibition effect on the enzymatic activity (P<0.05). The enzyme activity was significantly increased in the presence of Ca⁺² and Mg⁺² and decreased by Cu⁺², Ba⁺², Co⁺², Zn⁺², Fe⁺² and Al⁺³ (P<0.05). Na⁺ and K⁺ did not show any significant effect on the activity of enzyme (P>0.05). The enzymatic activity was significantly increased in presence of surfactants including saponin and sodium cholate and showed a significant decrease in presence of SDS and oxidizing agents like sodium perborate and hydrogen peroxide (P<0.05). Therefore, the results of this study showed that the chymotrypsin activity from beluga intestine had a significant decrease in presence of inhibitors, metal ions (except for Ca⁺², Mg⁺², K⁺ and Na⁺), SDS, sodium perborate and hydrogen peroxide and showed a significant increase in presence of Ca⁺² and Mg⁺², saponin and sodium cholate that it can be affected the maximum activity of the enzyme in digestive physiology of the beluga.