الفهرس 
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Abstract
Cardiovascular diseases (CVDs) have emerged as a global health concern and an economic burden, causing high mortality and morbidity worldwide. Blood clots (thrombosis) are the major cause of CVD. Microbial fibrinolytic enzymes have important applications as anti-thrombotic and thrombolytic agents. This study aimed to isolation of local fungal isolates from different soil samples, screening for fibrinolytic enzyme activity and production of enzyme using submerged fermentation method then purification the produced enzyme from Scopulariopsis brevicaulis OS 3456 that had been reported as the highest potential producer of thrombolytic protease by 80% ammonium sulphate precipitation, dialysis, and gel filtration chromatography using Sephadex G-100. The specific activity of the enzyme was 370 U/mg after purification with a yield of 1.5% and a purification fold of 3.4. The molecular weight of the purified enzyme was 61.5 kDa determined by SDS-PAGE analysis. The optimum temperature of the enzyme was 37oC and it was stable over a broad pH range of 5.0–9.0 with maximum stability at pH 7.0. The activity was increased in the presence of Mn2+, Ba2+, ß-Me, triton X-100, Xylene, and Hexane by 51.6, 41.4, 137.1, 37.5, 23, and 4%, respectively. Furthermore, the enzyme activity was strongly inhibited by Cd2+, Al3+, Hg2+, EDTA, PMSF, acetone, and ethyl acetate. The in vitro thrombolytic activity of the undiluted purified enzyme (370 U/mg) was found to be 100%. Meanwhile, in the cases of 185, 92.5, 46.25, 23.125, and 11.562 U/mg, the clot lysis percentage was 76.8, 67.4, 57.8, 39.5, and 28%, respectively. A carrageenan-induced tail thrombosis model was applied to test the in vivo thrombolytic activity of the enzyme. The result indicated no obvious thrombus in the tail of mice treated with the tested enzyme 370 U/mg. However, when the enzyme was diluted, its thrombolytic activity decreased gradually. All these results explore the promising thrombolytic activity of the extracted fibrinolytic enzyme. Hence, more purification steps and more experimental animal studies are required in the future for its use as a commercial drug.