The researchers also found that the synthesis of the active form of bdnf is critically dependent on a seemingly unrelated enzyme system in the body known as tpa plasmin , which may provide hints for further research on the mechanism of long - term memory formation （ tpaplasmin ）的酵素系统，是制造活跃的bdnf的决定性因素；这项发现为将来深入研究长期记忆形成的机制，提供了重要线索。
2.
All the currently used thrombolytic agents are plasminogen activators , which are very efficient in restoring the blood flow . they can convert plasminogen into plasmin and thus degrade fibrin . despite the widespread use of established thrombolytic agents such as streptokinase , t - pa and u - pa , all these agents suffer from a number of inadequacies including resistance to reperfusion , occurrence of coronary reocclusion and bleeding complications 介绍了国内外溶栓剂蛋白质工程方面的新进展，主要涉及了组织型纤溶酶原激活剂t - pa尿激酶型纤溶酶原激活剂u - pa链激酶sk葡萄球菌激酶sak dspa及tsv - pa的研究进展。
3.
They can convert plasminogen into plasmin and thus degrade fibrin . despite the widespread use of established thrombolytic agents such as streptokinase , t - pa and u - pa , all these agents suffer from a number of inadequacies including resistance to reperfusion , occurrence of coronary reocclusion and bleeding complications 一些pa突变体及新型溶栓剂，如k2p tnk - pa和star等的临床实验结果表明它们在延长体内半寿期增强对血纤维蛋白选择性和溶栓效率等方面有较大的改进。
