Evidence that multiple proteases of Bacillus subtilis can degrade fibrin and fibrinogen

Fibrinolytic enzyme produced by Bacillus spp. are known to possess an unique property to degrade fibrin blood clots. Fibrinolytic enzyme such as nattokinase has commercial applications as a therapeutic agents and functional food formulation. In this study, we report an interesting characteristic feature of Bacillus subtilis BR21, a native isolate for its ability to produce multiple proteases that exclusively acts on fibrin and fibrinogen. The crude enzyme preparation was made from the culture grown in soybean powder supplemented Luria Bertani broth. The culture filtrate was found to contain proteases, that could collectively degrade fibrin and fibrinogen effectively. Zymogram indicated presence of six fibrinolytic proteases and these degraded all the four peptide chains of fibrin rapidly. However, only Aα, Bβ chains of fibrinogen were highly susceptible to the enzymes. Activity inhibition by PMSF and EDTA indicated the presence of serine and metallo proteases. Fibrinolytic and fibrinogenolytic activities, specifically the ability to degrade γ-γ′ dimer of fibrin, promises its potential as both therapeutic and prophylactic agents, for thrombosis related disorders as this remains undegraded in such conditions. The fibrinolytic ability of multiple proteases together may help in developing cheaper and effective orally administrable thrombolytic preparations.