Inhibitory properties of a novel human Kunitz-type protease inhibitor homologous to tissue factor pathway inhibitor
Inhibitory properties of a novel human Kunitz-type protease inhibitor homologous to tissue factor pathway inhibitor
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DOI：
10.1021/bi951501d
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发表时间：
1996-01-09
期刊：
影响因子：
2.9
通讯作者：
Kisiel, W
中科院分区：
文献类型：
--
作者：
Petersen, LC;Sprecher, CA;Kisiel, W
在先前的报道中，我们描述了第二种人组织因子途径抑制剂（TFPI）的分子克隆、表达和部分表征，我们将其命名为TFPI-2 [Sprecher，C.一、等人（1994）Proc.Natl. Acad. Sci. U.S.A.91，3353-3357]。重组TFPI-2抑制胰蛋白酶以及与组织因子复合的因子VIIa的酰胺分解活性。TFPI-2最近已被证明与胎盘蛋白5（PP 5）相同，PP 5是一种最初从胎盘分离的糖蛋白，其表现出丝氨酸蛋白酶抑制活性。在本研究中，我们已经检查了TFPI-2/PP 5的能力，以抑制一些丝氨酸蛋白酶参与血液凝固和纤维蛋白溶解，因为TFPI-2/PP 5延长凝血时间的人血浆诱导的组织因子或接触活化以剂量依赖性的方式。除了其抑制因子Wa-组织因子复合物的酰胺分解和蛋白水解活性的能力之外，TFPI-2/PP 5强烈抑制人因子XIa、人血浆激肽释放酶和人纤溶酶的酰胺分解活性，Ki值为15、25和3 nM。分别TFPI-2/PP 5也是通过人因子IXa和聚赖氨酸的复合物激活因子X的弱抑制剂，表观Ki为410 nM。肝素显着增强的能力，TFPI-2/PP 5抑制因子Ⅶ a-组织因子在溶液相和细胞表面。另外。肝素在相对高水平（10-100 nM）的TFPI-2/PP 5下增强了对人因子Xa酰胺分解活性的抑制。当这些蛋白酶在不存在肝素的情况下与TFPI-2孵育时，未观察到腺激肽释放酶、尿纤溶酶原激活物、组织纤溶酶原激活物、人活化蛋白C、人Xa因子、人凝血酶或白细胞弹性蛋白酶的显著抑制。
In a previous report, we described the molecular cloning, expression, and partial characterization of a second human tissue factor pathway inhibitor (TFPI), which we designated as TFPI-2 [Sprecher, C. A., et al. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 3353-3357]. Recombinant TFPI-2 inhibited the amidolytic activity of trypsin as well as that of factor VIIa in complex with tissue factor. TFPI-2 recently has been shown to be identical to placental protein 5 (PP5), a glycoprotein originally isolated from placenta that exhibits serine protease inhibitory activity. In the present study, we have examined TFPI-2/PP5 for its ability to inhibit a number of serine proteases involved in blood coagulation and fibrinolysis, inasmuch as TFPI-2/PP5 prolonged the coagulation time of human plasma induced by either tissue factor or contact activation in a dose-dependent manner. In addition to its ability to inhibit the amidolytic and proteolytic activities of the factor Wa-tissue factor complex, TFPI-2/PP5 strongly inhibited the amidolytic activities of human factor XIa, human plasma kallikrein, and human plasmin with K-i values of 15, 25, and 3 nM. respectively. TFPI-2/PP5 was also a weak inhibitor of the activation of factor X by a complex of human factor IXa and poly(lysine) with an apparent K-i of 410 nM. Heparin markedly enhanced the ability of TFPI-2/PP5 to inhibit factor VIIa-tissue factor both in the solution phase and on cell surfaces. In addition. heparin augmented the inhibition of human factor Xa amidolytic activity at relatively high levels (10-100 nM) of TFPI-2/PP5. No significant inhibition of glandular kallikrein, urinary plasminogen activator, tissue plasminogen activator, human activated protein C, human factor Xa, human thrombin, or leukocyte elastase was observed when these proteases were incubated with TFPI-2 in the absence of heparin.