Harlos K, Holland S K, Boys C W, Burgess A I, Esnouf M P, Blake C C
Laboratory of Molecular Biophysics, University of Oxford, UK.
Nature. 1987;330(6143):82-4. doi: 10.1038/330082a0.
The later stages of the blood coagulation cascade are characterized by the presence of vitamin K-dependent proteins and their involvement in membrane-bound, multi-protein converting complexes with an essential requirement for calcium ions. Specific interactions between zymogens and activating enzymes have not yet been identified. Here we describe a crystallographic study of prothrombin fragment 1 (residues 1-156 of prothrombin) which indicates that vitamin K-dependent coagulation proteins have specific association sites that allow them to form hetero-dimers. The calcium-induced formation of a hetero-dimer between fragment 1 and factor X is demonstrated by cross-linking. Such hetero-dimers of vitamin K-dependent proteins could be significant in the coagulation system.
血液凝固级联反应的后期阶段以维生素K依赖蛋白的存在以及它们参与膜结合的多蛋白转化复合物为特征，这些复合物对钙离子有基本需求。目前尚未确定酶原与激活酶之间的具体相互作用。在此，我们描述了凝血酶原片段1（凝血酶原的第1至156位残基）的晶体学研究，该研究表明维生素K依赖的凝血蛋白具有特定的结合位点，使其能够形成异二聚体。通过交联证明了片段1与因子X之间钙诱导的异二聚体形成。维生素K依赖蛋白的这种异二聚体在凝血系统中可能具有重要意义。
