Zhang Shuli, Wang Yingdong, Zhang Nan, Sun Zhe, Shi Yan, Cao Xingnan, Wang Haikuan
Key Laboratory of Industrial Fermentation Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Ministry of Education, Tianjin, PR China.
Food Technol Biotechnol. 2015 Jun;53(2):243-248. doi: 10.17113/ftb.53.02.15.3874.
Extracellular fibrinolytic enzyme from var. was purified and characterised. The microorganism was isolated in a distillery from daqu, a fermentative agent used in the production of Chinese liquor and vinegar at different temperatures. The fibrinolytic enzyme was partially purified by ammonium sulphate precipitation, dialysis, DEAE Sepharose Fast Flow ion exchange chromatography and Sephadex G-75 gel filtration chromatography. The molecular mass of the fibrinolytic enzyme was estimated to be 24.5 kDa by SDS-PAGE. The purified enzyme showed optimal activity at pH=7.0 and 37 °C by fibrin plate method. It showed stronger resistance to the inhibition by trypsin and was stable at 37 °C retaining 96.1% residual activity after 4 h of incubation. The fibrinolytic activity of the enzyme was enhanced by Na, Ca, Mg and Mn. Conversely, Zn and Cu partly inhibited enzymatic activity. Using fibrin plate method, we found that the enzyme not only degrades fibrin directly, but also activates plasminogen into plasmin to degrade fibrin. The results indicate that the pure enzyme has a potential in dissolving blood clot, and the possibility for application in the treatment of thrombosis.
对[菌株名称]的胞外纤溶酶进行了纯化和表征。该微生物是在一家酿酒厂从大曲中分离得到的，大曲是在不同温度下用于生产中国白酒和醋的发酵剂。通过硫酸铵沉淀、透析、DEAE Sepharose Fast Flow离子交换色谱和Sephadex G - 75凝胶过滤色谱对纤溶酶进行了部分纯化。通过SDS - PAGE估计纤溶酶的分子量为24.5 kDa。采用纤维蛋白平板法测定，纯化后的酶在pH = 7.0和37℃时表现出最佳活性。它对胰蛋白酶的抑制作用具有较强的抗性，在37℃下稳定，孵育4小时后保留96.1%的残余活性。Na、Ca、Mg和Mn可增强该酶的纤溶活性。相反，Zn和Cu部分抑制酶活性。采用纤维蛋白平板法发现，该酶不仅能直接降解纤维蛋白，还能将纤溶酶原激活为纤溶酶来降解纤维蛋白。结果表明，该纯酶在溶解血栓方面具有潜力，有应用于治疗血栓形成的可能性。
