Purification and characterization of a novel fibrinolytic enzyme from Whitmania pigra Whitman.

Abstract Developing an effective fibrinolytic drug for treating thrombolysis with minimal undesirable side effects is of great importance. In the current study, an optimum solvent was selected for the extraction of fibrinolytic active components. Furthermore, a strong fibrinolytic enzyme named WPI01 was purified from Whitmania pigra Whitman through various chromatographic steps. WPI01 has a molecular mass of 27044.297 Da, and the N-terminal 8 amino acid sequence was determined as VVGGVEAR. WPI01 was stable within the pH range of 6.0–10.0 and with maximum fibrinolytic activity at 40 °C and a pH of 8.0. At 500 U/mL, WPI01 induced 50.59% blood clot reduction in vitro within 6 h, which was higher than that induced by urokinase at 1000 U/mL. In an analysis of the plasminogen activator activity, WPI01 produced obvious halos on heated and unheated fibrin plates, suggesting that WPI01 may not only act as a plasminogen activator but also degrade fibrin clots directly, and more study is needed to support this. In conclusion, WPI01 is obviously different from known fibrinolytic enzymes in terms of substrate specificity and fibrinolytic mode of action, suggesting that it is a novel fibrinolytic enzyme with potential applications in the treatment and prevention of thrombosis.