THE (DD)E COMPLEX IS MAINTAINED BY A COMPOSITE FIBRIN POLYMERIZATION SITE
THE (DD)E COMPLEX IS MAINTAINED BY A COMPOSITE FIBRIN POLYMERIZATION SITE
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DOI：
10.1021/bi00248a001
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发表时间：
1994-11-08
期刊：
影响因子：
2.9
通讯作者：
BUDZYNSKI, AZ
中科院分区：
文献类型：
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作者：
MOSKOWITZ, KA;BUDZYNSKI, AZ
（DD）E复合物是主要的交联纤维蛋白降解片段。为了更好地了解凝块结构和聚合过程中特定多肽链段的贡献，检查了维持（DD）E复合物所需的结构组分。首先，（DD）E复合物被衍生自具有GPR（α 17-19）的最小序列的纤维蛋白的α-链NH 2-末端的肽可逆地解离。此外，复合物被肽β 40-54部分解离，而β 50-55和来自纤维蛋白β链NH 2-末端的肽没有影响。第二，特异于纤维蛋白α-链NH 2-末端的单克隆抗体（mAb）1B 6与片段E（1）快速反应，但不识别（DD）E复合物上的相应表位。另一方面，对纤维蛋白β链NH 2末端的GHRPL具有特异性的mAb 59 D8以剂量依赖性方式与（DD）E复合物反应。第三，（DD）E复合物通过凝血酶或响尾蛇蛋白酶III对片段E（1）的蛋白水解裂解而不可逆地解离，凝血酶将GPR从α链NH 2末端除去，响尾蛇蛋白酶III释放β 15-42。已经得出结论，片段E（1）含有至少由残基α 17-19和β 20-49组成的复合聚合位点，它们一起维持（DD）E复合物。这些结果表明，复合物是保持在一起的互补结合位点，形成一个核的线性纤维蛋白聚合位点。因此，（DD）E复合物可以被认为是纤维蛋白凝块的可溶性模型。纤维蛋白β-链NH 2-末端，GHRPL，似乎是可用的（DD）E复合物的表面上，因此可以作为一个横向聚合位点的功能。
The (DD)E complex is the major cross-linked fibrin degradation fragment. Structural components required for maintenance of the (DD)E complex were examined in order to better understand clot structure and the contribution of specific polypeptide chain segments in the process of polymerization. First, the (DD)E complex was reversibly dissociated by peptides derived from the alpha-chain NH2-terminus of fibrin having a minimal sequence of GPR (alpha 17-19). In addition, the complex was partially dissociated by peptide beta 40-54, while beta 50-55 and peptides derived from the fibrin beta-chain NH2-terminus had no effect. Second, monoclonal antibody (mAb) 1B6, specific for the alpha-chain NH2-terminus of fibrin, reacted rapidly with fragment E(1), but did not recognize the corresponding epitope on the (DD)E complex. On the other hand, mAb 59D8, specific for GHRPL at the beta-chain NH2-terminus of fibrin, reacted with the (DD)E complex in a dose-dependent manner. Third, the (DD)E complex was irreversibly dissociated by proteolytic cleavage of fragment E(1) by either thrombin, which removed GPR from the alpha-chain NH2-terminus, or Crotalus atrox protease III, which released beta 15-42. It has been concluded that fragment E(1) contains a composite polymerization site consisting at least of residues alpha 17-19 and beta 20-49, which together maintain the (DD)E complex. These results illustrate that the complex is kept together by complementary binding sites which form a nucleus of linear fibrin polymerization sites. The (DD)E complex can thus be considered as a soluble model of fibrin clot. The fibrin beta-chain NH2-terminus, GHRPL, appears to be available on the surface of the (DD)E complex and may thus function as a lateral polymerization site.