CAJ | 학술논문

尿激酶原催化纤溶酶原的激活包括3个反应:(1)尿激酶原内在酶活性催化纤溶酶原转化为纤溶酶;(2)纤溶酶激活尿激酶原变成尿激酶;(3)尿激酶激活纤溶酶原,所以一直以来人们对尿激酶原激活纤溶酶原的过程知之甚少.研究发现EACA可以抑制尿激酶原催化的纤溶酶原激活.通过EACA对上述3个反应的影响进行逐个分析,观察到在EACA浓度为2.0mmol/L时,尿激酶原内在酶活性催化纤溶酶原激活的反应速度提高了4.5倍,尿激酶激活纤溶酶原的反应速度提高了6倍.相反地,纤溶酶激活尿激酶原变成尿激酶的反应被抑制了50%,此反应决定了EACA对尿激酶原催化纤溶酶原激活反应的抑制作用.该结果提示尿激酶原催化纤溶酶原激活反应的限速步骤是纤溶酶激活尿激酶原变成尿激酶,缘于纤溶酶和尿激酶原的赖氨酸结合位点的相互作用.
뇨격매원최화섬용매원적격활포괄3개반응:(1)뇨격매원내재매활성최화섬용매원전화위섬용매;(2)섬용매격활뇨격매원변성뇨격매;(3)뇨격매격활섬용매원,소이일직이래인문대뇨격매원격활섬용매원적과정지지심소.연구발현EACA가이억제뇨격매원최화적섬용매원격활.통과EACA대상술3개반응적영향진행축개분석,관찰도재EACA농도위2.0mmol/L시,뇨격매원내재매활성최화섬용매원격활적반응속도제고료4.5배,뇨격매격활섬용매원적반응속도제고료6배.상반지,섬용매격활뇨격매원변성뇨격매적반응피억제료50%,차반응결정료EACA대뇨격매원최화섬용매원격활반응적억제작용.해결과제시뇨격매원최화섬용매원격활반응적한속보취시섬용매격활뇨격매원변성뇨격매,연우섬용매화뇨격매원적뢰안산결합위점적상호작용.
Prourokinase catalyzed plasminogen activation is poorly understood since it includes following three reactions and is complicate for kinetics analysis: (1) the intrinsic activity of prourokinase activates plasminogen to plasmin; (2) plasmin activates prourokinase to urokianse; (3) urokinase activates plasminogen. In this paper, EACA was found to inhibit prourokinase catalyzed plasminogen activation. To analyze this inhibitory effect, the three reactions were separately studied. It was found that in the presence of 2.0 mmol/L EACA,plasminogen activation by the intrinsic activity of prourokinase and that by urokinase were promoted by 4.5 and 6-fold, respectively. In contrast, prourokinase activation by plasmin was found inhibited by 50%,suggested that it was responsible for the overall inhibitory effect of EACA on prourokinase catalyzed plasminogen activation. This also indicated that the rate-limited step of prourokinase catalyzed plasminogen activation was prourokinase activation by plasmin that was assisted by a lysine binding site(s) dependent interaction between plasmin and prourokinase.