Mechanical regulation of von Willebrand factor

血管性血友病因子的机械调节

• 批准号: 10296176
• 负责人: Xiaohui Zhang
• 金额: $ 60.69万
• 依托单位: LEHIGH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10296176
• 关键词: Address; Adhesions; Affect; Amino Acids; Area; Binding; Binding Proteins; Biological Assay; Biomechanics; Biophysical Process; Blood Circulation; Blood Coagulation Disorders; Blood Platelets; Blood Vessels; Blood coagulation; C-terminal; Cardiovascular Diseases; Coagulation Process; Collagen; Complex; Defect; Detection; FDA approved; Fluorescence; Fluorescence Microscopy; Glycoprotein Ib; Hematological Disease; Hemorrhage; Human; Human body; Inherited; Investigation; Lead; Link; Location; Mechanics; Mediating; Modeling; Molecular; Mutate; Mutation; N-terminal; Nature; Pathogenesis; Pharmaceutical Preparations; Plasma Proteins; Platelet Glycoproteins; Platelet aggregation; Play; Polysaccharides; Population; Prevention; Prevention strategy; Property; Protein Biochemistry; Protein Chemistry; Proteins; Reagent; Regulation; Reporting; Role; Series; Serine; Sialic Acids; Site; Spectrum Analysis; Structure; Testing; Therapeutic; Threonine; Thrombosis; Thrombotic Thrombocytopenic Purpura; Variant; base; biophysical techniques; biophysical tools; design; disulfide bond; experimental study; gain of function mutation; glycoprotein receptor GPIb-IX; glycosylation; mechanical properties; models and simulation; molecular dynamics; molecular modeling; nanobodies; new therapeutic target; novel; novel therapeutic intervention; preempt; prevent; protein function; receptor; single molecule; success; von Willebrand Disease; von Willebrand Factor

PROJECT SUMMARY/ABSTRACT In human bodies, bleeding is stopped when a clot is formed at the site of vascular damage. Under rapid flow conditions, the plasma protein von Willebrand factor (VWF) plays an indispensable role in capturing both platelets and collagen on damaged vessel walls, allowing the formation of platelet plugs. The adhesion between VWF and platelets is mediated by the interaction between the A1 domain of VWF and the Ib chain of the platelet receptor GPIb-IX complex. Gain-of-function mutations in A1 that enhance this interaction lead to type 2B von Willebrand disease (VWD). Targeting the A1GPIb-IX interaction has been an emerging strategy to treat or preempt bleeding and thrombotic disorders, though success in this area has been very limited. The lack of progress is due largely to the enigmatic nature of how exactly A1 remains inactive in blood circulation and how it is instantly activated to bind to GPIb-IX upon bleeding. Our recent identification of an autoinhibitory module (AIM), consisting of N- and C-terminal flanking regions on A1 and their O-linked glycans, is crucial for understanding A1 mechanoactivation during bleeding. In addition, AIM can be unfolded by a tensile pulling force of 8 to 20 pN. Based on these preliminary discoveries, we hypothesize that O-linked glycan structures, particularly sialic acids, further stabilize AIM and contribute to the mechanical regulation of A1GPIb-IX binding and that modulating AIM’s mechanical properties can be utilized to treat or preempt blood diseases. We propose to test this potentially paradigm-shifting hypothesis using state-of-the-art analytical biophysical tools, including single-molecule force spectroscopy, single-molecule fluorescence microscopy and all-atom molecular dynamics simulation. Three specific aims will be pursued to test the hypotheses. Aim 1 is to characterize the structure and biomechanical properties of AIM. Aim 2 is to determine how autoinhibition is regulated by O-linked glycosylation in AIM. And Aim 3 is to investigate the role of AIM in type 2B VWD and therapeutic applications. Completion of the proposed studies will identify the key molecular and biophysical mechanisms underlying how AIM mechanically regulates VWF function and platelet binding and will aid in devising novel therapeutic strategies for the prevention and treatment of human blood disease.

项目摘要/摘要 在人体中，当血管损伤部位形成凝块时，停止了出血。在快速流动下 条件，血浆蛋白von Willebrand因子（VWF）在捕获两者中起着必不可少的作用 血小板和胶原蛋白受损的容器壁，允许形成血小板塞。之间的粘合剂 VWF和血小板是由VWF的A1域与IB链之间的相互作用介导的 血小板接收器GPIB-IX复合物。 A1中功能的突变增强了这种相互作用导致类型 2B von Willebrand疾病（VWD）。靶向A1GPIB-IX相互作用已成为治疗的新兴策略 或抢占出血和血栓性疾病，尽管该领域的成功非常有限。缺乏 进步主要是由于A1在血液循环中仍然不活跃的神秘性及其如何 立即激活在出血时与GPIB-IX结合。我们最近对自身抑制模块的识别 （AIM）由A1上的N和C末端侧翼区域及其O连接的聚糖组成，对 了解出血期间的A1机械活化。此外，拉伸力可以展开目标 8至20 pn。基于这些初步发现，我们假设O链接的聚糖结构， 特别是唾液酸，进一步稳定目标并有助于A1GPIB-IX结合的机械调节 并且可以使用调节AIM的机械性能来治疗或抢占血液疾病。我们建议 使用最先进的分析生物物理工具，包括 单分子力光谱，单分子荧光显微镜和全原子分子 动力学模拟。将追求三个具体目标以检验假设。目标1是表征 目标的结构和生物力学特性。 AIM 2是确定如何通过O-Linch调节自身抑制作用 目标中的糖基化。目标3是研究目标在2B型VWD和治疗应用中的作用。 拟议研究的完成将确定如何进行分子和生物物理机制 AIM机械调节VWF功能和血小板结合，并有助于设计新的治疗 预防和治疗人类血液疾病的策略。