Gonias S L, Pasqua J J, Greenberg C, Pizzo S V
Thromb Res. 1985 Jul 1;39(1):97-116. doi: 10.1016/0049-3848(85)90125-2.
Incubation of histone H3 with normal citrated plasma resulted in the formation of insoluble aggregates, as determined by turbidity measurements. The precipitate was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis, confirming that fibrinogen was a major component. Purified fibrinogen precipitated rapidly as determined with turbidity experiments and experiments with radioiodinated protein. The amount of fibrinogen precipitation was strongly dependent on H3 concentration. Variation of ionic strength (0.2-0.84) and pH (5.3-7.4), however, had little or no effect on the reaction. Fibrinogen subjected to gelatin-Sepharose chromatography or dialysis against 3.3M urea reacted equivalently with H3. Precipitation of 125I-fibrinogen by H3 was strongly favored by increasing temperature (4 degrees-45 degrees C). Precipitation of fibrinogen by protamine was maximized by decreasing the temperature. In addition, formation of insoluble fibrinogen-protamine aggregates was highly dependent on ionic strength and pH, suggesting that different types of protein-interaction are involved in the two studied precipitation reactions. Of the fibrinogen degradation products, only fragment X precipitated significantly when incubated with H3. Radioiodinated fibrin monomer also precipitated when incubated with H3 in solutions of sufficient ionic strength to prevent spontaneous polymerization. The extent of precipitation was equivalent for fibrin monomer and fibrinogen. Fragment D inhibited the precipitation of fibrinogen by H3 or protamine. These studies indicate that the proteins termed "paracoagulants" are not all equivalent and that the hydrophobic domain of H3 plays a critical role in fibrinogen precipitation.
通过浊度测量发现，组蛋白H3与正常枸橼酸盐血浆孵育会导致不溶性聚集体的形成。将沉淀物进行十二烷基硫酸钠聚丙烯酰胺凝胶电泳，证实纤维蛋白原是主要成分。通过浊度实验和放射性碘化蛋白实验确定，纯化的纤维蛋白原沉淀迅速。纤维蛋白原沉淀的量强烈依赖于H3的浓度。然而，离子强度（0.2 - 0.84）和pH（5.3 - 7.4）的变化对该反应几乎没有影响。经过明胶 - 琼脂糖凝胶色谱或用3.3M尿素透析的纤维蛋白原与H3反应效果相同。升高温度（4℃ - 45℃）强烈促进H3对125I - 纤维蛋白原的沉淀。降低温度可使鱼精蛋白对纤维蛋白原的沉淀作用达到最大。此外，不溶性纤维蛋白原 - 鱼精蛋白聚集体的形成高度依赖于离子强度和pH，这表明在这两个研究的沉淀反应中涉及不同类型的蛋白质相互作用。在纤维蛋白原降解产物中，只有片段X与H3孵育时会显著沉淀。在具有足够离子强度以防止自发聚合的溶液中，放射性碘化纤维蛋白单体与H3孵育时也会沉淀。纤维蛋白单体和纤维蛋白原的沉淀程度相当。片段D抑制H3或鱼精蛋白对纤维蛋白原的沉淀。这些研究表明，被称为“副凝血剂”的蛋白质并非都等同，并且H3的疏水结构域在纤维蛋白原沉淀中起关键作用。
