Hrynenko T V, Iusova O I, Zadorozhna M B, Makohonenko Ie M
Palladin Institute of Biochemistry, NAS of Ukraine, Kyiv.
Ukr Biokhim Zh (1999). 2002 Nov-Dec;74(6):83-90.
The kinetic of plasmin, Va1442-plasmin, Lys530-plasmin inhibition reaction by alpha 2-antiplasmin as well as interaction of the inhibitor with different derivatives of the plasminogen and its fragments were studied. It was shown that plasmin, mini- and micro-plasmin activity decreased by 97, 88 and 85%, respectively, for equimolar ratio 1:1 of the inhibitor. The value of the inhibition reached its maximum in 1-2, 5-10 and 10-15 min, respectively. The constants of the complex formation rate were 1.4 x 10(6); 1.7 x 10(5) and 6.2 x 10(4) M-1s-1 for the plasmin, mini- and micro-plasmin with alpha 2-antiplasmin, respectively. Both 10(-2) M 6-aminohexanoic acid and 10(-1) M arginine reduced the complex formation rate between plasmin, mini-plasmin and alpha 2-antiplasmin to the value of the rate reaction between micro-plasmin and inhibitor. alpha 2-Antiplasmin bound with all investigated derivatives and fragments of plasminogen. The amount of inhibitor decreased in the series: plasmin, kringle 1-3, kringle 4, mini-plasminogen, micro-plasminogen. The kringle 1-4 and kringle 5 were determined to control the rate of reaction between enzyme and inhibitor, being not necessary for the inhibition. The comparison of the inhibitor interaction with DPP-plasmin, mini-plasminogen and micro-plasminogen displayed the possibility of the additional region existence in catalytic domain. This region participated in the complex with alpha 2-antiplasmin formation. It is supposed that the multisite interaction between plasmin and alpha 2-antiplasmin provides for the specificity and efficiency the inhibitor action.
研究了α2-抗纤溶酶对纤溶酶、Va1442-纤溶酶、Lys530-纤溶酶抑制反应的动力学，以及该抑制剂与纤溶酶原不同衍生物及其片段的相互作用。结果表明，对于1:1等摩尔比的抑制剂，纤溶酶、微型纤溶酶和微型纤溶酶的活性分别降低了97%、88%和85%。抑制值分别在1 - 2分钟、5 - 10分钟和10 - 15分钟达到最大值。纤溶酶、微型纤溶酶和微型纤溶酶与α2-抗纤溶酶形成复合物的速率常数分别为1.4×10(6)、1.7×10(5)和6.2×10(4) M-1s-1。10(-2) M 6-氨基己酸和10(-1) M精氨酸都将纤溶酶、微型纤溶酶与α2-抗纤溶酶之间的复合物形成速率降低到微型纤溶酶与抑制剂之间的反应速率值。α2-抗纤溶酶与所有研究的纤溶酶原衍生物和片段结合。抑制剂的量在以下序列中减少：纤溶酶、kringle 1 - 3、kringle 4、微型纤溶酶原、微型纤溶酶原。确定kringle 1 - 4和kringle 5控制酶与抑制剂之间的反应速率，它们对于抑制不是必需的。抑制剂与DPP-纤溶酶、微型纤溶酶原和微型纤溶酶原相互作用的比较显示，催化结构域中可能存在额外区域。该区域参与了与α2-抗纤溶酶复合物的形成。据推测，纤溶酶与α2-抗纤溶酶之间的多位点相互作用为抑制剂作用提供了特异性和效率。
