Purification and characterization of a caseinolytic enzyme from Bacillus subtilis.

Elkenawi, Ebtesam G.; Elsayed, A; El-Senduny, Fardous F.; Youssef, Magdy M.

doi:10.21608/mjcc.2022.412087

Purification and characterization of a caseinolytic enzyme from Bacillus subtilis.

Document Type : Original Article

Authors

¹ Chemistry Department,Faculty of Science, Mansoura University, Mansoura

² Botany Department, Faculty of Science, Mansoura University, Mansoura

³ Chemistry Department, Faculty of Science, Mansoura University, Mansoura

10.21608/mjcc.2022.412087

Abstract

Nattokinase (EC 3.4.21.62) is a serine protease and profibrinolytic enzyme with a strong fibrin-degrading activity, and many host strains can produce it. By its comparison with other fibrinolytic enzymes such as (streprokinase, urokinase and t-PA), nattokinase showed many advantages of having long life-time, no side effects, costless and it owns the ability to be a drug candidate for treatment of heart diseases and used as an effective food additive. Bacillus subtilis natto discovered in natto, a typical Japanese fermented soybean food. After the purification of Nattokinase from the supernatant of B. subtilis culture media, it showed a strong fibrinolytic activity. The enzyme was refined to a 4.4-fold purity level, with 61.8 percent of activity recovered. SDS-PAGE showed that nattokinase is homogenous and identified it as a monomer of 29000 Da in its original state. The optimum temperature and pH were 65°c and 9.0 respectively. Purified nattokinase is thermally stable at temperatures ranging from 35 to 55 °C and alkaline stable at pH 7.0 to 10.0. Skim milk agar showed clear zone of crude enzyme. Mg²⁺increased the activity of nattokinase, but Zn²⁺ and Fe³⁺ decreased the activity. Triton x-100 as detergent significantly increased activity of nattokinase on the contrast to SDS inhibit nattokinase activity.

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