Elastase activity in natto, and its relation to nattokinase

In commercially obtained natto, 12 kinds of cereal and okara-natto preparat ions, both elastase and nattokinase activities were found. Particularly, in the natto preparations fermented with broad beans, soybeans, or green bean s showed much stronger elastase activity, and it was also confirmed in Baci llus natto cells after ultrasonication. Using the commercially obtained nattokinase and natto extract, elastase act ivity in the eluate of isoelectricfocussing was parallel to that of nattoki nase activity. Highly purified natto-elastase was proved to be identical to nattokinase by pi (about 8.7, isoelectric focussing), molecular weight (ab out 20,000, gel filtration), and also by NH2-terminal amino acid sequence ( 21 residues) identified by Edmans method.