重组PAI－1对u－PA抑制活性的研究

利用大肠杆菌表达的重组纤溶酶原激活物抑制因子－１（ｒＰＡＩ－１）具有许多与天然ＰＡＩ－１相同的性质，ｒＰＡＩ－１对ｕ－ＰＡ抑制活性研究的内容包括：几种化学物质（盐酸胍、尿素、硫氰酸钾、ＳＤＳ、氯化钠等）对ｒＰＡＩ－１的激活作用、盐酸胍激活ｒＰＡＩ－１的浓度与温度效应、显色底物法和ＳＤＳ－ＰＡＧＥ纤维蛋白自显影对ｒＰＡＩ－１活性的测定、活性态ｒＰＡＩ－１向潜状态的转变及其与盐浓度和ｐＨ值的关系。

Study of Inhibitory Activity of Recombinant PAI-1 on u-PA

Many properties of recombinant plasminogen activator inhibitor-1 (rPAI-1) expressed in E.coli are identical with those of natural PAI-1. The study of activation of rPAI-1 by certain chemicals showed that guanidine HCl, urea and KSCN could change rPAI-1 from latent form to active form, while SDS, NaCl could not do this. Reactivated rPAI-1 could inhibit u-PA in a dosage manner. Guanidine HCl could activate rPAI-1 when guanidine HCl was in a high concentration (over 3 mol/L) and was treated with rPAI-1 at certain temperature. When reactivated rPAI-1 was incubated at 37℃, it could transform from active form to latent form spontaneously, and the speed of this transformation was inversely proportional to the concentration of NaCl. Reactivated rPAI-1 exhibited drifting value of inhibitory activity at different PH value. While the inhibitory activity of rPAI-1 on u-PA was tested by chromogenic substrate assay. it could also be visually identified by fibrin autography on SDSPAGE film.