title: Starase: A bi-functional fibrinolytic protease from hepatic caeca of Asterina pectinifera displays antithrombotic potential.
abstract: A bi-functional fibrinolytic serine protease, Starase exhibiting thrombolytic potency was purified from hepatic caeca of Asterina pectinifera. Starase showed a single band of approximately 48 kDa by SDS-PAGE and fibrin zymography. The N-terminal sequence of Starase was AIPTEFDARTKKHNN, which does not match with any known fibrinolytic enzyme. Starase had optimum amidolytic activity at 50 °C and pH 8.0 and the activity was inhibited by PMSF and APMSF. Starase showed the highest specificity toward the substrate H-D-Val-Leu-Lys-pNA for plasmin followed by pyroGlu-Gly-Arg-pNA for urokinase. The apparent Km and Vmax values of Starase toward a chromogenic substrate for plasmin H-D-Val-Leu-Lys-pNA were determined as 1.37 mM and 6.8 mM/min/mg respectively. The fibrinolytic activity of Starase by fibrin plate assay displayed that it could not only directly degrade fibrin clot but also activate plasminogen. Starase showed a strong fibrinogenolytic activity, cleaving all three major chains of fibrinogen rapidly. In addition, Starase with more than 1 μg could cleave extracellular matrix component type VII collagen, and plasma proteins such as bovine albumin and bovine gamma globulin. It could also inhibit factor Xa and thrombin activity. Starase at a dose of 0.8 mg/kg was devoid of hemorrhagic activity and it demonstrated antithrombotic effect in three animal models; FeCl2-induced carotid arterial thrombus model, carrageenan-induced tail thrombosis model and collagen and epinephrine induced pulmonary thromboembolism mice model. These results suggest that Starase has the potential to be a potent thrombolytic agent due to its bi-functional properties (containing both direct-acting and plasminogen-activating activities) and lack of hemorrhagic activity. Although Starase might interfere with the normal composition of the plasma proteins, it may be used not only for the treatment and prevention of thrombosis, but also in a number of biomedical applications.
authors: Department of Life Science & BK21-Plus Research Team for Bioactive Control Technology, Chosun University, Gwangju 501-759, Republic of Korea.
authors: Jun-Hui
authors: JH
authors: Choi
authors: Central Department of Zoology, Tribhuvan University, Kirtipur, Kathmandu, Nepal.
authors: Kumar
authors: K
authors: Sapkota
authors: Department of Alternative Medicine, Gwangju University, Gwangju 503-703, Republic of Korea.
authors: Seung
authors: S
authors: Kim
authors: Department of Life Science & BK21-Plus Research Team for Bioactive Control Technology, Chosun University, Gwangju 501-759, Republic of Korea. Electronic address: sjbkim@chosun.ac.kr.
authors: Sung-Jun
authors: SJ
authors: Kim
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D047288:Asterina / Q000737:chemistry / Q000201:enzymology*; D024143:Collagen Type VII / Q000737:chemistry / Q000378:metabolism; D005337:Fibrin / Q000378:metabolism; D005340:Fibrinogen / Q000378:metabolism; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D051379:Mice; D010958:Plasminogen / Q000737:chemistry / Q000378:metabolism; D057057:Serine Proteases / Q000008:administration & dosage / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D013379:Substrate Specificity; D015912:Thrombolytic Therapy; D013927:Thrombosis / Q000188:drug therapy* / Q000473:pathology
chemical_list: D024143:Collagen Type VII; D005343:Fibrinolytic Agents; D005337:Fibrin; D005340:Fibrinogen; D010958:Plasminogen; D057057:Serine Proteases
keywords: Antithrombosis; Bi-functional enzyme; Fibrinolysis; Starase