CAJ | 학술논문

反应体系中存在的纤维蛋白（fibrin）对尿激酶（UK）、scu-PA以及组织型纤溶酶原激活剂（t-PA）激活纤溶酶原（plasminogen）的反应有不同的作用：UK、t-PA激活plasminogen的反应可被反应体系中存在的fibrin所加强；fibrin对scu-PA激活 plasminogen反应的动力学常数无明显影响；但对小分子质量scu-PA与单链抗体的嵌合分子激活plasminogen的反应起明显的抑制作用.为确定反应体系中存在的fibrin对scu-PA的K区插入突变体-InB激活plasminogen反应的影响，测定了在反应体系中存在fibrin的情况下的In B激活plasminogen反应的Kfibrinm以及kfibrincat.Kfibrinm＝4.2 μmol*L-1，远远大于无fibrin时的Km＝0.379 μmol*L-1，说明有fibrin存在时突变体InB与天然底物plasminogen的亲和性降低了.kfibrincat＝0.107 s-1，也远远大于无fibrin时kcat＝0.0165 s-1，说明有fibrin存在时突变体InB对plasminogen的反应活性增强了.原因可能是：与fibrin结合的plasminogen的构象发生了有利于被纤溶酶原激活剂水解的变化.
반응체계중존재적섬유단백（fibrin）대뇨격매（UK）、scu-PA이급조직 형섬용매원격활제（t-PA）격활섬용매원（plasminogen）적반응유불동적작용：UK、t-PA격활plasminogen적반응가피반응체계중존재적fibrin소가강；fibrin대scu-PA격활 plasminogen반응적동역학상수무명현영향；단대소분자질량scu-PA여단련항체적감합분자 격활plasminogen적반응기명현적억제작용.위학정반응체계중존재적fibrin대scu-PA적K구 삽 입돌변체-InB격활plasminogen반응적영향，측정료재반응체계중존재fibrin적정황하적In B격활plasminogen반응적Kfibrinm이급kfibrincat.Kfibrinm＝4.2 μmol*L-1，원원대우무fibrin시적Km＝0.379 μmol*L-1，설명유fibrin존재시돌변체InB여천연저물plasminogen적친화 성강저료.kfibrincat＝0.107 s-1，야원원대우무fibrin시kcat＝0.0165 s-1，설명유fibrin존재시돌변체InB대plasminogen적반 응활성증강료.원인가능시：여fibrin결합적plasminogen적구상발생료유리우피섬용매원격 활제수해적변화.
Because the influence of fibrin on the reaction of plasm inogen activation by various plasminogen activators is different, the kinetic co nstant of the reaction of plasminogen activation catalyzed by InB with and witho ut fibrin were detected. The result is: Kfibrinm＝4.2 μmol*L -1，greater than the normal Km=0.379 μmol*L-1; kfib rincat＝0.107 s-1，greater than the normal kcat=0.0165 s-1. The results suggest that existence of fibrin in the reaction system of plasminogen activation depress the affinity between InB and plasminog en, but accelerates the hydrolysis of plasminogen by InB. The count up effect is inhibition.