Bovine plasminogen activator inhibitor 1: specificity determinations and comparison of the active, latent, and guanidine-activated forms.
Bovine plasminogen activator inhibitor 1: specificity determinations and comparison of the active, latent, and guanidine-activated forms.
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牛纤溶酶原激活剂抑制剂 1：活性、潜伏和胍激活形式的特异性测定和比较。
DOI：
10.1021/bi00408a037
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发表时间：
1988
期刊：
影响因子：
2.9
通讯作者：
Loskutoff,DJ
中科院分区：
文献类型：
--
作者：
Hekman,CM;Loskutoff,DJ
免疫学系，Scripps诊所和研究基金会，拉霍亚，加州92037，和化学系，加州大学，圣地亚哥，拉霍亚，加州92093，接收日期：1987年6月12日;修订版手册，接收日期：1987年12月23日摘要：纤溶酶原激活物抑制剂1（派-1）由培养的牛主动脉内皮细胞合成并释放的一种多肽以可被胍激活的潜伏形式存在于条件培养基中盐酸盐[Hekman，C. M.，& Loskutoff，D. J.（1985）J.Biol.Chem.260，11581-11587]。纯化的、胍激活的派-1对纤溶酶和胰蛋白酶均有抑制作用，并呈剂量和时间依赖性。纤溶酶和胰蛋白酶的二级速率常数分别为6.6 × 105和7.0 × 106 M-1 s-1。进行实验以比较派-1的固有活性和胍活化形式。这两种活性形式与尿激酶（ATd，0.3 pM; fcasein，1.5 × 108 M™ 1 s-1）相互作用的动力学参数相似，并且在用酸或碱处理以及在37 ℃温育时均失活。在相似条件下孵育时，潜伏型相对稳定。在37 ℃孵育时派-1活性的降低可通过盐酸胍的第二次处理而部分恢复。然而，在37 ℃下，恢复程度作为温育时间的函数而降低。这些数据表明，活性和胍激活的派-1代表派-1的单一形式。这种形式在37 ℃下孵育产生两种不同的失活派-1群体，一种能够再活化，另一种似乎是不可逆失活的。纤维蛋白的特异性溶解由蛋白酶纤溶酶催化，该蛋白酶纤溶酶作为无活性酶原存在于血浆中，纤溶酶原（Collen，1980）。纤溶酶的产生是通过纤溶酶原激活剂尿激酶（UK）1和组织纤溶酶原激活剂（tPA）对纤溶酶原的有限切割而发生的。除了它们在纤维蛋白溶解中的作用之外，纤溶酶原激活剂（PA）还涉及各种其他生物过程，包括排卵（Beers等人，
Department of Immunology, Scripps Clinic and Research Foundation, La Jolla, California 92037, and Department of Chemistry, University of California, San Diego, LaJolla, California 92093 Received June 12, 1987; Revised Manuscript Received December 23, 1987 abstract: The plasminogen activatorinhibitor 1 (PAI-1) synthesized and released by cultured bovine aortic endothelial cells is present in conditioned medium in a latent form that can be activated by guanidine hydrochloride [Hekman, C. M., & Loskutoff, D. J.(1985) J. Biol. Chem. 260, 11581-11587]. The purified, guanidine-activated PAI-1 was shown to inhibit both plasmin and trypsin in a dose-andtime-dependent manner. Second-order rate constants for these interactions were calculated to be 6.6 X 105 and 7.0 X 106 M-1 s_1 for plasmin and trypsin, respectively. Experiments were conducted to compare the inherently active and the guanidine-activated forms of PAI-1. The two active forms had similar kinetic parameters for interaction with urokinase (ATd, 0.3 pM; fcassoc, 1.5 X 108 M™ 1 s_1) and were both inactivated upon treatment with acid or base andby incubation at 37 C. The latent form was relatively stablewhen incubated under similar conditions. Thedecrease in PAI-1 activity upon incubation at 37 C was partially restored by a second treatment with guanidine hydrochloride. However, the degree of recovery decreased as a function of incubation time at 37 C. These data suggest that active and guanidine-activated PAI-1 represent a single form of PAI-1. Incubation of this form at 37 C yields two distinct populations of inactive PAI-1, one capable of reactivation and anotherthat appears to be irreversibly inactivated. e specific lysis of fibrin is catalyzed by the protease plasmin that exists in plasma as the inactive zymogen, plas-minogen (Collen, 1980). The generation of plasmin occurs through the limited cleavage of plasminogen by the plasmi-nogen activators, urokinase (UK), 1 and tissue plasminogen activator (tPA). In addition to their role in fibrinolysis, the plasminogen activators (PA’s) have been implicated in various other biological processes including ovulation (Beers et al.,