School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.
Beijing Institute of Radiation Medicine, Beijing, 100850, People's Republic of China.
J Thromb Thrombolysis. 2021 Oct;52(3):880-888. doi: 10.1007/s11239-021-02440-4. Epub 2021 Apr 7.
In the present study, bifunctional fusion proteins were designed by fusing the kringle 2 and protease domains of tissue-type plasminogen activator (tPA) to the C-terminal fragment of hirudin. The thrombolytic and anticoagulant activities of these recombinant proteins from mammalian cells were investigated using in vitro coagulation models and chromogenic assays. The results showed that all assayed tPA mutants retained catalytic activity. The C-terminal fragment of hirudin may have weak affinity to thrombin and thus was insufficient to suppress thrombin-mediated fibrin agglutination. The strength of the thrombolytic activity only relied on the selected tPA sequences, and the fibrinolytic efficiency of single-chain protein significantly decreased. Our data indicate that truncated tPA combined with a hirudin peptide may provide a framework for the further development of a new antithrombotic agent.
在本研究中，通过将组织型纤溶酶原激活物（tPA）的kringle 2 和蛋白酶结构域融合到水蛭素的 C 末端片段，设计了双功能融合蛋白。使用体外凝血模型和比色测定法研究了这些来自哺乳动物细胞的重组蛋白的溶栓和抗凝活性。结果表明，所有测定的 tPA 突变体均保留催化活性。水蛭素的 C 末端片段可能与凝血酶具有弱亲和力，因此不足以抑制凝血酶介导的纤维蛋白聚集。溶栓活性的强度仅取决于所选的 tPA 序列，单链蛋白的纤维蛋白溶解效率显著降低。我们的数据表明，截短的 tPA 与水蛭素肽的结合可能为进一步开发新型抗血栓形成剂提供了框架。
