The Discovery Process of Nattokinase

Nattokinase (NK) (EC 3.4.21.62) is an alkaline serine protease secreted by Bacillus subtilis (natto), which has the advantages of long half-life, strong specificity, and minimal side effects.

The discovery of nattokinase  comes from the famous “2:30 pm experiments“.

One day in 1980, Japanese cardiovascular and cerebrovascular expert Dr. Hiroyuki Sumi, who was engaged in the research of thrombolytic drugs, suddenly remembered that natto was not fermented with fibrin? The most stubborn part of blood clots is fibrin. So, at 2:30 pm, Dr. Hiroyuki Sumi added the substance extracted from natto to the artificial thrombus.

He was originally planning to see the results the next day, but at 5:30 pm, by chance, a miracle happened. The blood clot actually dissolved by 2 centimeters, and the experiment of using urokinase to dissolve the blood clot required nearly two days. That is to say, the speed at which natto fermentation products dissolve blood clots is 19 times faster than that of urokinase. So, the powerful thrombolytic agent of nattokinase was named nattokinase, abbreviated as NK, which is the famous 2:30 pm experiment in the history of thrombolytic drug research that shocked the world.

NattoKinase (NK) is a protein extracted from food natto or produced by natto bacteria. It is a protein with a molecular weight much smaller than UK, SK, and tPA, and can be absorbed by the intestine. The in vitro and in vivo thrombolytic properties of NK have also been determined through experiments. At the same time, it has been found that the in vivo thrombolytic activity of NK is four times that of plasmin, and it acts quickly and for a long time in vivo. It can also activate tPA in the body, making it mildly and continuously improve the fibrinolytic activity of the blood.