In silico analysis of Nattokinase from Bacillus subtilis sp natto

Nattokinase or subtilisin NAT (EC 3.4.21.62) is one of the most remarkable enzymes produced by Bacillus subtilis sp. Natto, which posses direct fibrinolytic activity. The aim of this study is in silico analysis of Nattokinase structure and function. The three-dimensional structure of serine protease Nattokinase from Bacillus subtilis sp. natto was determined using homology modeling performed by Geno3D2 Web Server and refined by ModRefiner. The obtained models were validated via programs such as RAMPAGE, ERRAT, 3D Match and verify 3D for consistency; moreover, functional analysis performed by PFP from Kihara Bioinformatics laboratory. RAMPAGE analysis showed that 96.7% of the residues are located in the favored region, 3.0% in allowed region and 0.4% in outlier region of the Ramachandran plot. The verify 3D value of 0.73 indicates that the environmental sketch of the model is fine. SOPMA and PSIPRED were exploited for computation of the secondary structural properties of serine protease Nattokinase. Active site determination via AADS suggested that this enzyme can be applied as a potent enzyme for cardiovascular therapy. However, these results should be more confirmed by wet lab researches for designing the more active enzyme for better functions on its fibrinolysis activity.