Purification and partial characterization of TFase, a fibrinolytic enzyme from the fruiting bodies of the medicinal and edible mushroom, Tremella fuciformis

摘要

A fibrinolytic metalloprotease-like enzyme named TFase, was purified from the fruiting bodies of the medicinal fungus Tremella fuciformis. Purification of TFase was performed by a chromatography on DEAE Sepharose CL-6B and Superdex-75. TFase showed a molecular weight of 38 kDa by SDS-PAGE and displayed a strong fibrin zymogram lysis band corresponding to a similar molecular mass. The enzyme demonstrated wide temperature optimum from 10 to 40A degrees C and pH optimum at pH 8.0. The fibrinolytic activity of TFase was strongly inhibited by EDTA and EGTA, which are metalloprotease inhibitors. The K (m) and V (max) values for enzyme using the artificial substrate pyroGlu-Gly-Arg-pNA were 3.81 mM and 4.88 A mu moles mg(-1) min(-1), respectively. TFase of T. fuciformis partially dissolved a fibrin clot directly and specifically cleaved the A alpha and B beta chains of fibrinogen. In addition, the enzyme prolonged the coagulation time, and increased the activated partial thromboplastin time and prothrombin time. These results suggest that TFase of T. fuciformis exhibits properties of a metalloprotease-like enzyme, shows novel fibrin(ogen)olytic enzyme activity, and has the potential to be a therapeutic agent for thrombosis.