BLOOD COAGULATION FACTOR

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 血液凝固是通过相互作用的促凝血因子和抗凝血因子之间的平衡来确保的。第VIII因子(FVIII)是一种大的多结构域蛋白(~280 kDa)，其活性形式为FVIIIa(FVIIIa)，与膜结合的Tenase复合体中的丝氨酸蛋白酶因子IXa(FixA)起辅助作用。 FVIIa与血小板表面FixA的结合使凝血因子Xa(FXA)和凝血酶的生成增加了106倍以上。FVIII基因突变导致轻微到严重的A型血友病，这是一种威胁生命的血液疾病，影响5000名男性人口中的一人(Wacey等人，1996年)。治疗这种疾病的唯一方法是静脉注射FVIII，Stoilova-McPhie使用电子显微镜研究了FVIII的膜结合结构(Parmenter和Stoilova-McPhie，2008；Stoilova-McPhie等人，2008)。 低温电子显微镜是一种独特的方法，能够确定蛋白质在其自然环境中的结构。为此，我们设计了用于FVIII及其络合物螺旋结晶的脂质纳米管(LNT)，使其膜-键结构可以通过Cryo-EM进行解析。 通过低温电子显微镜确定膜结合凝血因子Va和凝血因子VIIIa与脂质纳米管的结构是本项目的主要目标。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Blood coagulation is ensured through equilibrium between pro- and anti-coagulant coagulation factors that interact with each other and cells. Factor VIII (FVIII) is a large multidomain protein (~280kDa), which in its active form, Factor VIIIa (FVIIIa) acts as a co-factor to the serine protease Factor IXa (FIXa) within the membrane-bound Tenase complex. Binding of FVIIIa to FIXa onto the platelet surface increases Factor Xa (FXa) and Thrombin generation more than 10^6 times. Mutations in FVIII result in mild to severe Haemophilia type A, a life-threatening blood condition affecting one in 5000 of the male population (Wacey et al., 1996). The sole cure for this condition is intravenous administration of FVIII, whose membrane-bound structure has been studied by Stoilova-McPhie using electron microscopy (Parmenter and Stoilova-McPhie, 2008; Stoilova-McPhie et al., 2008). CryoEM is a unique method capable of defining the structure of proteins in their native environment. For this purpose we have designed lipid nanotubes (LNT) for helical crystallization of FVIII and its complexes, allowing its membrane-bond structure to be resolved by Cryo-EM. Defining the structure of membrane-bound blood coagulation Factor Va and Factor VIIIa attached to lipid nanotubes by Cryo-electron microscopy is the primary goal of this project.