Interactions Among Heparin, Cold-Insoluble Globulin, and Fibrinogen in Formation of the Heparin Precipitable Fraction of Plasma
Interactions Among Heparin, Cold-Insoluble Globulin, and Fibrinogen in Formation of the Heparin Precipitable Fraction of Plasma
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肝素、冷不溶性球蛋白和纤维蛋白原在血浆肝素可沉淀部分形成中的相互作用
DOI：
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发表时间：
1977
影响因子：
6.7
通讯作者：
M. Mosesson
中科院分区：
文献类型：
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作者：
N. Stathakis;M. Mosesson
纤维蛋白原和血浆冷不溶性球蛋白（CIg）是正常血浆肝素冷沉淀组分（HPF）的主要蛋白组分。这些蛋白质和肝素之间的相互作用进行了检查。肝素与纯化的CIg或CIg和纤维蛋白原的混合物（T/2，0.2; pH 7.2）形成冷沉淀复合物，但不与单独的纤维蛋白原形成冷沉淀复合物。冷沉淀可以通过添加Ca++或通过选择最佳肝素水平来增强;它可以通过提高离子强度或pH值或两者，或通过将肝素水平提高到高于CIg最大沉淀所需的水平来减少或甚至消除。纤维蛋白原降低了肝素诱导的冷沉淀发生时CIg的阈值水平，并且通过与肝素和CIg共沉淀，增加了形成的总沉淀。与正常血浆中同时含有纤维蛋白原和CIg的HPF相反，无纤维蛋白原血症血浆中含有CIg但缺乏纤维蛋白原。正常血浆耗尽的CIg未能形成肝素诱导的冷沉淀。因此，CIg是肝素诱导的冷沉淀发生所必需的。通过肝素-琼脂糖色谱柱的色谱实验评估，纤维蛋白原的肝素结合亲和力比CIg低得多，表明它主要（如果不是完全）通过其对CIg的亲和力参与HPF的形成。
Fibrinogen and the cold-insoluble globulin of plasma (CIg) are the main protein components of the heparin cryoprecipi table fraction (HPF) of normal plasma. The interactions between these proteins and heparin were examined. Heparin formed a cold precipitable complex with purified CIg or with mixtures of CIg and fibrinogen (T/2, 0.2; pH 7.2) but not with fibrinogen alone. Cryoprecipitation could be augmented by addition of Ca++ or by selection of optimal heparin levels; it could be reduced or even abolished by raising the ionic strength or pH or both, or by raising the heparin level above that needed for maximum precipitation of CIg. Fibrinogen reduced the threshold level of CIg at which heparin-induced cryoprecipitation occurred and, by co-precipitating with heparin and CIg, increased the total precipitate that formed. In contrast to the HPF from normal plasma which contained both fibrinogen and CIg, that from afibrinogenemic plasma contained CIg but lacked fibrinogen. Normal plasma depleted of CIg failed to form a heparin-induced cryoprecipitate. Thus, CIg is essential for heparin-induced cryoprecipitation to occur. Fibrinogen, as assessed by chromatographic experiments with heparin-Sepharose columns, has a considerably lower heparin-binding affinity than does CIg, indicating that it participates in formation of the HPF mainly, if not entirely, by virtue of its affinity for CIg.