Purification and characterization of a novel fibrinolytic protease from Fusarium sp. CPCC 480097.

A novel fibrinolytic enzyme from Fusarium sp. CPCC 480097, named Fu-P, was purified to electrophoretic homogeneity using ammonium sulfate precipitation and ion exchange and gel filtration chromatography. Fu-P, a single protein had a molecular weight of 28 kDa, which was determined by SDS-PAGE and gel filtration chromatography. The isoelectric point of Fu-P determined by isoelectric focusing electrophoresis (IEF) was 8.1, and the optimum temperature and pH value were 45 degrees C and 8.5, respectively. Fu-P cleaved the alpha-chain of fibrin (ogen) with high efficiency, and the beta-chain and gamma-gamma (gamma-)-chain with lower efficiency. Fu-P activity was inhibited by EDTA and PMSF, and the enzyme exhibited a high specificity for the chymotrypsin substrate S-2586. Fu-P was therefore identified as a chymotrypsin-like serine metalloprotease. The first 15 amino acids of the N-terminal sequence of Fu-P were Q-A-S-S-G-T-P-A-T-I-R-V-L-V-V and showed no homology with that of other known fibrinolytic enzymes. This protease may have potential applications in thrombolytic therapy and in thrombosis prevention.