Nattokinase

Nattokinase (pronounced nah-TOH-kin-ayss) is an enzyme originally extracted from a Japanese food called nattō. Nattō is produced by fermentation by adding the bacterium Bacillus subtilis var. natto, which also produces the enzyme, to boiled soybeans. In spite of its name, nattokinase is not a kinase enzyme (and should not be pronounced as such, i.e. nah-toh-KYN-ayss), but an extracellular serine protease of the subtilisin family (99.5% identical with subtilsin E). Rather, it is named for the fact that it is an enzyme produced by nattōkin (Japanese: 納豆 菌). This enzyme is known as subtilisin NAT (S08.044) in the MEROPS database. Synonyms include nattokinase, subtilisin QK, subtilisin QK02. The gene encodes a prepropeptide with a signal peptide and an inhibitor propeptide before the main enzyme chain (residues 107–381, theoretic molecular mass 27726.74). It has the designation Bac s 1 under the WHO/IUIS allergen nomenclature.