Platonova T N, Musialkovskaia A A, Tolstykh V M, Belitser V A
Biokhimiia. 1980 Oct;45(10):1780-7.
The influence of purified fragments D and DD on fibrin monomer polymerization has been studied. When applied separately, DD is less strong an inhibitor than D. An addition of small amounts of DD to the reaction mixtures containing D does not change the inhibitory effect, when the concentration of the latter fragment is low. At high concentrations of D the contribution of DD becomes more pronounced. Small amounts of D added to DD-containing systems strongly enhances the inhibition. These properties of the D--DD mixtures are unpredictable and puzzling; they contradict the generally accepted view that the specific inhibitors of fibrin polymerization, to which D and DD belong, act in a simple competitive way. The whole incomprehensible situation may be clarified in terms of a hypothesis on a two-step mechanism of inhibition. It is assumed that at the first (preliminary) step of the inhibitor effect DD is less competent than D, whereas at the second step DD possessing a high affinity for the fibrin monomer, functions as the most effective competitive inhibitor.
已对纯化的片段D和DD对纤维蛋白单体聚合的影响进行了研究。当单独应用时，DD作为抑制剂的作用不如D强。当D片段浓度较低时，向含有D的反应混合物中添加少量DD不会改变抑制作用。在D的高浓度下，DD的作用变得更加明显。向含DD的体系中添加少量D会强烈增强抑制作用。D-DD混合物的这些特性是不可预测且令人困惑的；它们与普遍接受的观点相矛盾，即D和DD所属的纤维蛋白聚合特异性抑制剂以简单的竞争方式起作用。根据抑制的两步机制假说，整个难以理解的情况可能会得到澄清。假定在抑制剂作用的第一步（初步），DD的作用不如D，而在第二步，对纤维蛋白单体具有高亲和力的DD作为最有效的竞争性抑制剂起作用。
