Tissue factor pathway inhibitor is highly susceptible to chymase-mediated proteolysis.
Tissue factor pathway inhibitor is highly susceptible to chymase-mediated proteolysis.
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组织因子途径抑制剂对食糜酶介导的蛋白水解高度敏感。
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
S. Kamei
中科院分区：
文献类型：
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作者：
T. Hamuro;H. Kido;Y. Asada;K. Hatakeyama;Y. Okumura;Y. Kunori;T. Kamimura;S. Iwanaga;S. Kamei
组织因子途径抑制剂（TFPI）是一种多价 Kunitz 型蛋白酶抑制剂，主要抑制凝血的外源途径。它由多种细胞合成，其表达水平在炎症环境中增加。肥大细胞和中性粒细胞在炎症和血管疾病部位积聚，释放蛋白酶以及这些疾病的化学介质。在这项研究中，研究了 TFPI 与人类肥大细胞和中性粒细胞分泌的丝氨酸蛋白酶之间的相互作用。 TFPI可灭活人肺类胰蛋白酶，其抑制活性强于抗凝血酶。相反，肥大细胞食糜酶即使在酶与底物摩尔比为1:500的情况下也会快速裂解TFPI，导致TFPI抗凝血和抗（因子Xa）活性显着降低。 N 端氨基酸测序和蛋白水解片段的 MS 分析表明，食糜酶优先在 Tyr159-Gly160、Phe181-Glu182、Leu89-Gln90 和 Tyr268-Glu269 处依次切割 TFPI，从而导致三个单独的 Kunitz 结构域的分离。中性粒细胞来源的蛋白酶 3 也裂解 TFPI，但反应比食糜酶反应慢得多。相比之下，α-胰凝乳蛋白酶表现出与食糜酶相似的底物特异性，导致 TFPI 降解水平明显较低。这些数据表明 TFPI 是一种新型且高度敏感的食糜酶底物。我们认为食糜酶介导的 TFPI 蛋白水解可能会在炎症部位诱导血栓形成倾向状态。
Tissue factor pathway inhibitor (TFPI) is a multivalent Kunitz-type protease inhibitor that primarily inhibits the extrinsic pathway of blood coagulation. It is synthesized by various cells and its expression level increases in inflammatory environments. Mast cells and neutrophils accumulate at sites of inflammation and vascular disease where they release proteinases as well as chemical mediators of these conditions. In this study, the interactions between TFPI and serine proteinases secreted from human mast cells and neutrophils were examined. TFPI inactivated human lung tryptase, and its inhibitory activity was stronger than that of antithrombin. In contrast, mast cell chymase rapidly cleaved TFPI even at an enzyme to substrate molar ratio of 1:500, resulting in markedly decreased TFPI anticoagulant and anti-(factor Xa) activities. N-terminal amino-acid sequencing and MS analyses of the proteolytic fragments revealed that chymase preferentially cleaved TFPI at Tyr159-Gly160, Phe181-Glu182, Leu89-Gln90, and Tyr268-Glu269, in that order, resulting in the separation of the three individual Kunitz domains. Neutrophil-derived proteinase 3 also cleaved TFPI, but the reaction was much slower than the chymase reaction. In contrast, alpha-chymotrypsin, which shows similar substrate specificities to those of chymase, resulted in a markedly lower level of TFPI degradation. These data indicate that TFPI is a novel and highly susceptible substrate of chymase. We propose that chymase-mediated proteolysis of TFPI may induce a thrombosis-prone state at inflammatory sites.