Takada A, Takada Y
Department of Physiology, Hamamatsu University, School of Medicine, Shizuoka, Japan.
Thromb Res. 1989 Sep 15;55(6):717-25. doi: 10.1016/0049-3848(89)90302-2.
The addition of tranexamic acid inhibited the conversion of single chain tissue plasminogen activator (sct-PA) to its two chain form (tct-PA) by plasmin. Increase in the concentrations of tranexamic acid resulted in more inhibition of the conversion, with 50% inhibition being obtained at 0.251 mM of the concentration of tranexamic acid. The addition of the fragments of plasminogen such as kringle 1 to 3 (K1-3), and K4 resulted in the facilitation of the conversion of sct-PA to tct-PA by plasmin. The addition of tranexamic acid to the mixture of sct-PA and K4 inhibited the rate of the conversion of sct-PA by plasmin. These results suggest that binding of lysine binding sites of plasmin or plasminogen with sct-PA enhanced its conversion to tct-PA by plasmin, and that there is a site on a t-PA molecule to bind to plasminogen or plasmin.
氨甲环酸的加入抑制了纤溶酶将单链组织型纤溶酶原激活剂（sct-PA）转化为其二链形式（tct-PA）。氨甲环酸浓度的增加导致对这种转化的抑制作用增强，当氨甲环酸浓度为0.251 mM时可达到50%的抑制率。加入纤溶酶原片段如kringle 1至3（K1-3）和K4可促进纤溶酶将sct-PA转化为tct-PA。向sct-PA与K4的混合物中加入氨甲环酸可抑制纤溶酶对sct-PA的转化速率。这些结果表明，纤溶酶或纤溶酶原的赖氨酸结合位点与sct-PA的结合增强了纤溶酶将其转化为tct-PA的能力，并且在t-PA分子上存在一个可与纤溶酶原或纤溶酶结合的位点。
