Potent fibrinolytic enzyme from a thermophilic Streptomyces megasporus strain SD5

As a therapeutic agent in thrombosis the fibrinolytic enzymes are of interest and the search for a new enzyme continues. A strong fibrin-specific fibrinolytic enzyme was purified from the cell-free spent broth of thermophilic Streptomyces megasporus strain SD5. The crude enzyme was concentrated using ammonium sulphate, dialysis and lyophilization. Approximately 0.11 mg ml(-1) crude enzyme with a specific activity of 4.2 U mug(-1) was obtained. Post-electrophoretic reactivity revealed a monomeric form of the enzyme with a molecular weight of 35 kDa. The optimum pH and temperature for production of the enzyme were 8 and 55 degreesC, respectively. The enzyme was resistant to a broad range of pH ranging from 6 to 9 and temperature ranging from 37 to 60 degreesC. The enzyme was a chymotrypsin-like serine peptidase and the activity of the enzyme was N-terminal-dependent. The in vitro clot lysis by the enzyme at 37 degreesC was encouraging.