A novel fibrinolytic enzyme (nattokinase) in the vegetable cheese Natto; a typical and popular soybean food in the Japanese diet

Experientia. 1987 Oct 15;43(10):1110-1. doi: 10.1007/BF01956052.


A strong fibrinolytic activity was demonstrated in the vegetable cheese Natto, which is a typical soybean food eaten in Japan. The average activity was calculated at about 40 CU (plasmin units)/g wet weight. This novel fibrinolytic enzyme, named nattokinase, was easily extracted with saline. The mol. wt and pI were about 20,000 and 8.6, respectively. Nattokinase not only digested fibrin but also the plasmin substrate H-D-Val-Leu-Lys-pNA (S-2251), which was more sensitive to the enzyme than other substrates tried. Diisopropyl fluorophosphate and 2,2,2-trichloro-1-hydroxyethyl-o,o-dimethylphosphate strongly inhibited this fibrinolytic enzyme.

MeSH terms

  • Chromatography, Gel
  • Drug Stability
  • Fibrinolysis*
  • Food*
  • Hydrogen-Ion Concentration
  • Isoelectric Point
  • Japan
  • Molecular Weight
  • Serine Endopeptidases / metabolism*
  • Serine Proteinase Inhibitors
  • Soybeans*
  • Substrate Specificity
  • Subtilisins*


  • Serine Proteinase Inhibitors
  • Serine Endopeptidases
  • Subtilisins
  • nattokinase