Abstract: Plant endophytes are among the most important resources of biologically active metabolites. Twenty-three endophyte strains residing in Trachelospermum jasminoides were cultivated in vitro with the cultures assayed for the fibrinolytic substance production. As a result, the culture of Verticillium sp. Tj33 was shown to be the most active. A fibrinolytic enzyme designated as verticase was subsequently purified from the supernatant of Verticillium sp. culture broth by a combination of DEAE-52, Sephadex G-75 and hydrophobic column chromatographies. Verticase, with its molecular mass of 31 kDa and pI of 8.5, was demonstrated to be homogeneous by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing electrophoresis. Verticase is an enzyme that hydrolyzes fibrin directly without activation of plaminogen. It was stable in a broad pH range from 4 through to 11 with the optimal reaction pH value and temperature shown to be around 9–10 and 50–60 °C, respectively. The fibrinolytic activity of verticase was severely inhibited by phenylmethylsulfony fluoride, indicating that verticase was a serine protease.

Key words: fibrinolytic serine protease, plant endophyte, protein purification, Trachelospermum jasminoides, verticase.