Reverse micelles extraction of nattokinase： From model system to real system

Nattokinase (also named subtilisin NAT) was pri- marily isolated from a traditional fermented food in Japan, ‘‘Natto’’, by Sumi et al.[1]. Since then more and more reports of pharmacological researches on natto- kinase demonstrated that nattokinase showed many advantages, such as longer half life, greater fibrinolytic activity than plasmin, availability for both oral admini- stration and intravenous instillation, both preventive and therapeutic measure against thrombosis, less risk of he…

Reverse micelles extraction of nattokinase: From model system to real system

Nattokinase is a novel fibrinolytic en- zyme, which is homologous to Subtilisin Carlsberg. In this paper, Subtilisin Carlsberg was taken as a model protein of nattokinase. Effects of pH, ionic strength, concentration of isopropanol on the extraction of Subtilisin Carlsberg with AOT/isooctane reverse mi- celles system were investigated. Further, the process of reverse micelles extraction of nattokinase from fermentation broth was studied. By taking the reverse micelles of AOT/isooctane as extractant to perform a full extraction cycle, it was found that about eighty percent of the total activity of nattokinase in the fer- mentation broth could be recovered and the purifica- tion factor was about 2.5. Homologous protein could be reasonably used as model protein of a target protein.