Wiggins R C, Loskutoff D J, Cochrane C G, Griffin J H, Edgington T S
J Clin Invest. 1980 Jan;65(1):197-206. doi: 10.1172/JCI109651.
Rabbit Hageman factor was proteolytically cleaved and activated by a homogenate prepared from cultured rabbit endothelial cells. Cleavage of radiolabeled Hageman factor was monitored by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Endothelial cell-mediated cleavage of Hageman factor was demonstrated both in a purified system and in plasma, was time and concentration dependent, and was associated with formation of the characteristic 28,000 M(r) form of active Hageman factor. The rate of cleavage of Hageman factor was not affected by Triton X-100 (Rohm and Haas, Co., Philadelphia, Pa.), hexadimethrine bromide (Polybrene, Aldrich Chemical Co., Inc., Milwaukee, Wis.), hirudin, soybean trypsin inhibitor, or antisera to plasminogen or prekallikrein. However, cleavage was enhanced by kaolin, and was inhibited by diisopropyl-fluorophosphate. The enzyme responsible for cleavage of Hageman factor was localized to the 100,000-g-sedimentable, subcellular fraction of the endothelial cell homogenate and was relatively specific, because neither radiolabeled rabbit Factor XI nor rabbit prekallikrein were themselves proteolytically cleaved by the endothelial cell homogenate. However, when these molecules were incubated with the homogenate in the presence of Hageman factor, both Factor XI and prekallikrein were cleaved, demonstrating that Hageman factor had been activated by the endothelial cell homogenate. Furthermore, the kallikrein generated by endothelial cell homogenate-activated Hageman factor was capable of liberating kinin from high molecular weight kininogen as measured by bioassay. Cultured rabbit endothelial cells, therefore, possess the capacity to activate Hageman factor by proteolysis. This may be one mechanism for Hageman factor activation in vivo.
兔哈格曼因子可被培养的兔内皮细胞制备的匀浆进行蛋白水解切割并激活。在十二烷基硫酸钠存在的情况下，通过聚丙烯酰胺凝胶电泳监测放射性标记的哈格曼因子的切割情况。内皮细胞介导的哈格曼因子切割在纯化系统和血浆中均得到证实，具有时间和浓度依赖性，并且与活性哈格曼因子特征性的28,000 M(r)形式的形成相关。哈格曼因子的切割速率不受曲拉通X-100（罗门哈斯公司，宾夕法尼亚州费城）、溴化六亚甲基双胺（聚凝胺，奥德里奇化学公司，威斯康星州密尔沃基）、水蛭素、大豆胰蛋白酶抑制剂或抗纤溶酶原或前激肽释放酶抗血清的影响。然而，高岭土可增强切割，而二异丙基氟磷酸可抑制切割。负责切割哈格曼因子的酶定位于内皮细胞匀浆中100,000 g可沉降的亚细胞部分，并且具有相对特异性，因为放射性标记的兔因子XI和兔前激肽释放酶本身均不会被内皮细胞匀浆进行蛋白水解切割。然而，当这些分子在哈格曼因子存在的情况下与匀浆一起孵育时，因子XI和前激肽释放酶均被切割，表明哈格曼因子已被内皮细胞匀浆激活。此外，通过生物测定法测定，内皮细胞匀浆激活的哈格曼因子产生的激肽释放酶能够从高分子量激肽原中释放激肽。因此，培养的兔内皮细胞具有通过蛋白水解激活哈格曼因子的能力。这可能是体内哈格曼因子激活的一种机制。
