In vitro thrombolytic activity of a purified fibrinolytic enzyme from Chlorella vulgaris.

A fibrinolytic enzyme was produced by microalga Chlorella vulgaris cultivated in autotrophic and mixotrophic conditions added corn steep liquor, purified by a single chromatographic step, then biochemical characterization and in vitro thrombolytic activity was performed. Maximum cell concentration (1637.45 ± 15 mg L) and productivity (181.93 mg L day) was obtained in mixotrophic culture using 1% corn steep liquor. Enzyme-extracted microalgal biomass was purified by acetone precipitation and DEAE Sephadex anion exchange chromatography up to 2 fold with recovery of 4.0%. After purification, fibrinolytic activity was 1834.6 U mg and 226.86 mm by spectrophotometry and fibrin plate assays, respectively. SDS-PAGE results exhibited a protein band of about 45 kDa and fibrinolytic band was detected by fibrin zymography. Enzyme activity was enhanced in the presence of Fe and inhibited by phenylmethane sulfonyl fluoride (PMSF) and ethylenediamine tetracetic acid (EDTA), which suggest it to be a metal-dependent serine protease. The extract also showed a red blood cell lysis <4% and in vitro thrombolytic activity of 25.6% in 90 min of reaction. These results indicate that the fibrinolytic enzyme from C. vulgaris may have potential applications in the prevention and treatment of thrombosis.