Purification And Characterization Of Nattokinase

In order to increase the fibrinolytic activity of nattokinase, the crude extract of natto was purified by using Butyl-Toyopearl chromatography, fibrinolytic activity fractions were selected through tube method. Fibrinolytic activity of nattokinase was measured according to the fibrin plate method. The molecular weight of nattokinase were evaluated in SDS-PAGE after isolation and purification. Preliminary stability experiments of nattokinase were performed under high temperature and relative humidity.The fraction components from the tube number 106 to 158 were showed strong fibrinolytic activity while compared with other tubes. The isolated enzyme displayed two sharp band on SDS-PAGE, and the molecular weight of nattokinase were could be calculated approximately 19,275 and 27,101, respectively. According to the increase rate of fibrinolytic activity, the purification fold was 50,and the recover rate of fibrinolytic activity was 75.57%. The results of stability experiment indicated that fibrinolytic activity and appearance of nattokinase were changed significantly in the condition of 40 and 60 . But no significant changes were appeared in 4 . Crude natto extract could preserve strong fibrinolytic activity under high humidity while the appearance changed during the period ofexperiment.After purification and isolation process, the fibrinolytic activity of nattokinase were significantly increased. The molecular weight of nattokinase is similar with the results of the reported.