A dual-function chymotrypsin-like serine protease with plasminogen activation and fibrinolytic activities from the GRAS fungus, Neurospora sitophila

作者：Deng, Yongping; Liu, Xiaolan^*; Katrolia, Priti; Kopparapu, Narasimha Kumar; Zheng, Xiqun^*

来源：International Journal of Biological Macromolecules, 2018, 109: 1338-1343.

DOI：10.1016/j.ijbiomac.2017.11.142

• Neurospora sitophila
• Fibrinolytic enzyme
• Chymotrypsin-like serine protease

In this study, we have isolated and characterized a fibrinolytic enzyme from the GRAS (Generally Recognized as Safe) fungus, Neurospora sitophila. The enzyme was purified by fractional ammonium sulfate precipitation, hydrophobic interaction, ion exchange and gel filtration chromatography to 45.2 fold with a specific activity of 415.6 U/mg protein. The native molecular mass of the enzyme was 49 kDa, while the denatured molecular mass was 30 kDa and 17.5 kDa, indicating that the enzyme was a hetero-dimer. It was optimally active at 50 degrees C and pH 7.4 and stable at human physiological temperature and pH. It was found to be a chymotrypsin-like serine protease which cleaved the synthetic chromogenic substrate, N-Succinyl-Ala-Ala-Pro-Phe-pNA for which the apparent K-m and V-max values were 0.24 mM and 4.17 x 10(-5) mM/s, respectively. The enzyme hydrolyzed all the chains of fibrinogen by cleaving a chain first, followed by beta chain and then gamma chain. Moreover, the enzyme possessed dual function of direct fibrinolysis as well as plasminogen activation. Due to its attractive biochemical and fibrinolytic properties and being from a GRAS fungus, the fibrinolytic enzyme has application as a safe and efficient thrombolytic drug.

• 出版日期2018-4
• 单位齐齐哈尔大学