Structural bases of ADAMTS-13 and VWF A2 interactions

描述(申请人提供)：本研究将主要在中国科学院北京生物物理研究所中国教授与楼继忠教授合作完成，作为美国国立卫生研究院R01HL093723-01A1基金的延伸。FIRCA的申请有一个应有的目标：1)扩大和提高家长资助；2)增加楼继忠博士团队的研究能力。其目的是阐明von Willebrand因子和ADAMTS-13之间分子相互作用的机械调节，这是生理止血和病理性血栓形成的关键相互作用。这种相互作用的异常可能导致von Willebrand病和血栓性血小板减少性紫癜。ADAMTS-13/VWF的相互作用是机械调节的，因为它们发生在循环的水动力环境中。我们对FIRCA赠款的假设是，流体动力诱导VWF A2结构域的展开，从而促进其与ADAMTS-13的相互作用，与ADAMTS-13的结合也将导致ADAMTS-13上的构象变化以进行有效的蛋白质分解，构象受A2展开程度和机械力的调节。这一广泛的假设将在两个特定的目标下进行验证：1)通过比较野生型(WT)VWF A2结构域和一组突变的VWF A2结构域的力和热诱导的展开途径来阐明2A型VWD的结构机制；2)建立ADAMTS-13/A2相互作用的原子模型，并确定这些相互作用如何调节A2的展开和ADAMTS-13的构象变化。这些具体目标是计算研究，补充了父母的资助。FIRCA赠款中提出的分子动力学模拟和分子模拟将有助于解释从父母赠款获得的实验数据，并提供机会设计新的实验来检验父母和FIRCA赠款的总体假设。破译机械力如何调控VWF A2的展开、ADAMTS-13构象以及两个分子之间的相互作用将为血管生理学和病理学提供关键的见解。因此，这些数据可能会为相关疾病的治疗提供新的方法。 与公共健康相关：FIRCA的这项提案以几种方式延长了父母的补助金。从父母那里获得的信息和FIRCA的这笔赠款将有助于开发治疗2A型血管性血友病和血栓性血小板减少性紫癜的新方法。

DESCRIPTION (provided by applicant): This research will be done primarily at Institute of Biophysics, Chinese Academy of Sciences in Beijing, China in collaboration with Professor Jizhong Lou as an extension of NIH grant R01 HL093723- 01A1. This FIRCA application has a due objective: 1) to expand and enhance the parent grant and 2) to increase the research capacity of Dr. Jizhong Lou's group. The goal of this and the parent proposal is to elucidate the mechanical regulation of molecular interactions between von Willebrand factor and ADAMTS- 13, which are key interactions on physiological hemostasis and pathological thrombosis. Malfunction in the interactions may lead to von Willebrand disease and thrombotic thrombocytopenic purpura. ADAMTS- 13/VWF interaction is regulated mechanically as they take place in the hydrodynamic environment of the circulation. Our hypothesis for this FIRCA grant is that hydrodynamic forces induce the unfolding of VWF A2 domain which promotes its interactions to ADAMTS-13, the binding with ADAMTS-13 will also lead to the conformational changes on ADAMTS-13 for efficient proteolysis and the conformations are regulated by the degree of A2 unfolding and mechanical forces. The broad hypothesis will be tested in two specific aims: 1) Elucidate the structural mechanisms of type 2A VWD by comparing the force- and thermo-induced unfolding pathways of wild-type (WT) VWF A2 domain and a panel of mutant VWF A2 domains, and 2) 2.Develop atomic models for the ADAMTS-13/A2 interactions and determine how these interactions regulate A2 unfolding and ADAMTS-13 conformational changes. These specific aims are computational studies, which complement the parent grant. The molecular dynamics simulations and molecular modeling proposed in the FIRCA grant will help to interpret the experimental data obtained from the parent grant and provide opportunities to design new experiments to test the overall hypothesis of the parent and the FIRCA grant. Decoding how mechanical forces regulate VWF A2 unfolding, ADAMTS-13 conformations and the interactions between the two molecules will provide key insights into vascular physiology and pathology. As a result, the data may office new therapeutic approaches to relevant diseases. PUBLIC HEALTH RELEVANCE: This FIRCA proposal extends the parent grant in several ways. Information obtained from the parent and this FIRCA grants will help develop new therapeutic approaches to type 2A von Willebrand disease and thrombotic thrombocytopenic purpura.