Structural and Biochemical Basis of the Vitamin K cycle

维生素K循环支持血液凝固，是抗凝药物的主要靶点。凝血 这些因子需要谷氨酸的D羧化作用来激活损伤部位。维生素K依赖者 羧化酶（VKGG）由维生素K辅因子的氧化驱动。维生素K环氧还原酶 （VKOR）再生这种辅因子;还原当量来自硫氧还蛋白样伴侣。VKOR是 华法林是治疗和预防血栓形成最常用的口服抗凝剂， 包括深静脉血栓形成、肺栓塞、中风和心肌梗塞的疾病。华法林 由于出血的高风险，其治疗窗较窄。更安全的VKOR抑制剂的设计 由于完全不了解VKOR的结构而受到阻碍。在K99阶段，我们 确定了VKOR与其还原伙伴（一种 硫氧还蛋白结构域（Li埃塔尔. Nature 2010）。该结构揭示了华法林的结合口袋和 从硫氧还蛋白结构域到VKOR的电子转移途径。对于ROO阶段，1）我们将确定 VKOR与华法林和其他香豆素类药物复合物的晶体结构。我们还将使用纯化的 VKOR蛋白质，以研究VKOR催化和华法林抑制的生物化学。这些研究将提供 合理药物设计的基础。2)我们将确定反应中间体的结构，以阐明 电子从硫氧还蛋白结构域流向VKOR的途径。我们亦会研究 人VKOR及其还原性伙伴。3)我们将进行γ-谷氨酰的结构研究 羧化酶（VKGC）。 我在华盛顿大学圣路易斯分校获得了一个全职、终身助理教授的职位。 Louis.学校拥有优良的研究环境，拥有设备齐全的实验室和顶级的 研究人员我的团队未来的研究将结合X射线晶体学，蛋白质 生物化学和细胞生物学。我的长期目标是了解维生素K的整个途径， 血液凝固

The vitamin K cycle supports blood coagulation and is a major target for anticoagulation drugs. Coagulation factors require Dcarboxylation of glutamic acids for activation at sites of injury. The vitamin K dependent ¿ carboxylase (VKGG) is driven by the oxidation of a vitamin K cofactor. The vitamin K epoxide reductase (VKOR) regenerates this cofactor; the reducing equivalent comes from a thioredoxin-like partner. VKOR is the target of warfarin, the most commonly used oral anticoagulant for treating and preventing thrombosis diseases including deep vein thrombosis, pulmonary embolism, stroke, and myocardial infarction. Warfarin has a narrow therapeutic window due to the high risk of hemorrhage. The design of safer VKOR inhibitors was impeded by the complete absence of structural knowledge of VKOR. During the K99 phase, we determined the structure of a bacterial homolog of VKOR in association with its reducing partner, a thioredoxin domain (Li etal.. Nature 2010). The structure reveals a binding pocket for warfarin and a pathway of electron transfer from the thioredoxin domain to VKOR. For the ROO phase, 1) we will determine the crystal structures of VKOR in complex with warfarin and other coumarin drugs. We will also use purified VKOR proteins to study the biochemistry of VKOR catalysis and warfarin inhibition. The studies will provide the basis for rational drug design. 2) We will determine structures of reaction intermediates to elucidate the pathway by which electrons flow from the thioredoxin domain to VKOR. We will also study the function of human VKOR with its reducing partners. 3) We will conduct structural studies ofthe gamma-glutamyl carboxylase (VKGC). I have obtained a full-time, tenure-track assistant professor position in the Washington University at St. Louis. The school has an excellent research environment with well-equipped laboratories and top researchers. Future research in my group will use a combination of X-ray crystallography, protein biochemistry, and cell biology. My long-term goal is to understand the entire vitamin K pathway that sustains blood coagulation.