Novel protease from the leaves of edible medicinal plantAster koraiensisNakai with antithrombotic activity: Purification and partial characterization

Abstract

Nakaiase, a novel protease with antithrombotic and anticoagulant properties was purified from the leaves of Aster koraiensis Nakai, an edible medicinal plant. It had a molecular weight of 23 kDa, as confirmed by SDS-PAGE analysis. The protease was active at 30 °C and pH 7.0. The amidolytic activity of nakaiase was inhibited by EDTA, EGTA, and several metal ions (Ca, Ni, and Zn). Nakaiase inhibited fibrin clot formation and degraded blood clot. It also inhibit activated factor X and thrombin enzymatic activity. In addition, nakaiase prolonged activated partial thromboplastin time and prothrombin time. Further, the protease exerted significant protective effects against thrombin-induced pulmonary thromboembolism in mice. Nakaiase at a dose of 20 mg/kg was devoid of hemorrhagic activity. These results suggest that nakaiase has similar property to metalloprotease-like protease, and has potential as a therapeutic agent for thrombosis owing to its antithrombotic properties and lack of hemorrhagic activity. Practical applications Aster koraiensis Nakai, an edible medicinal plant, has long been used as a traditional medicine and healthy food source in Korea because of its pharmacological efficacy. This study provides beneficial information regarding the antithrombotic potential of A. koraiensis Nakai and bioactive enzymes. Our findings clarify the antithrombotic activities of a new purified protease, which is useful in the development of potential natural pharmacological resources and agents for functional food and clinical application.