BLOOD COAGULATION FACTOR

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 通过相互作用和与细胞相互作用的促凝血因子和抗凝凝血因子之间的平衡来确保血液凝固。因子VIII（FVIII）是一种大的多结构域蛋白（~ 280 kDa），其活性形式为因子VIIIa（FVIIIa），在膜结合Tenase复合物内作为丝氨酸蛋白酶因子IXa（FIXa）的辅因子。 FVIIIa与血小板表面的FIXa结合可使Xa因子（FXa）和凝血酶生成增加10^6倍以上。 FVIII中的突变导致轻度至重度A型血友病，这是一种危及生命的血液疾病，影响5000名男性人群中的一人（Wacey等人，1996年）。这种病症的唯一治疗方法是静脉内施用FVIII，其膜结合结构已经由Stoilova-McPhie使用电子显微镜进行了研究（Parmenter和Stoilova-McPhie，2008; Stoilova-McPhie等人，2008年）。 CryoEM是一种独特的方法，能够在其天然环境中定义蛋白质的结构。为此，我们设计了脂质纳米管（LNT）的螺旋结晶的FVIII及其复合物，使其膜键结构，以解决冷冻EM。 通过冷冻电子显微镜确定膜结合凝血因子Va和因子VIIIa附着于脂质纳米管的结构是该项目的主要目标。

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.