Conformational dynamics of adhesive bonds

 描述（由申请方提供）：项目概述粘附受体是一类细胞表面受体，其与表面结合配体结合以介导细胞粘附至其他细胞或组织。粘附受体在生理学和疾病中起着关键作用，因此是广泛疾病的治疗干预的常见靶标。本项目的目标是了解动态构象变化，使粘附受体介导强的细胞粘附在体内，以开发更好的方法来抑制它们。这 该项目的重点是细菌粘附素FimH，它与大肠杆菌引起的尿路感染有关。这将为治疗或预防涉及耐药细菌的感染提供替代方法。该项目的新奇之处在于它解决了机械力如何调节粘附受体的动态构象变化。该项目测试了以下假设：FimH利用结合配体传递的拉伸机械力来紧密地封闭配体周围的结合口袋，从而在存在机械力的情况下实现极其紧密的结合。该项目将测试一种新型的“寄生虫”抑制剂即使在机械力存在下也可以直接打开FimH结合口袋的假设。该项目还将测试的假设，即FimH将更有效地抑制在生理条件下的寄生抑制剂比传统的正构或变构抑制剂。为实现这些目标，将采用以下方法。1)在存在旁位、正构和变构抑制性抗体的情况下，测量FimH的结合动力学，包括有和无机械力。2)FimH的结构和构象动力学将确定在三种类型的抗体的存在下，使用NMR，X射线晶体学和原子结构模拟。3)将比较三种类型的抗体的有效性，用于预防细菌粘附到泌尿上皮细胞，以及小鼠的尿路感染。这项工作将为FimH疫苗和抑制剂的设计提供理论依据。这项工作还将为开发许多其他粘附受体的抑制剂提供理论基础，这些粘附受体是血栓性和炎症性疾病、癌症和许多其他疾病的治疗干预的有吸引力的靶点。

 DESCRIPTION (provided by applicant): PROJECT SUMMARY Adhesive receptors are a class of cell surface receptor that binds to surface-bound ligands to mediate cell adhesion to other cells or tissues. Adhesive receptors play a critical role in physiology and disease, and so are common targets for therapeutic interventions for a wide range of diseases. The goal of this project is to understand the dynamic conformational changes that allow adhesive receptors to mediate strong cell adhesion in vivo, in order to develop better methods for their inhibition. This project focuses on the bacterial adhesin FimH, which is implicated in infection of the urinary tract by Escherichia coli. This should provide alternative methods to treat or prevent infections involving antibiotic-resistant bacteria. The novelty of this project is that it addresses how mechanical force regulates the dynamic conformational changes of adhesive receptors. This project tests the hypothesis that FimH utilizes tensile mechanical force transmitted by the bound ligand to close the binding pocket tightly around the ligand, allowing extremely tight binding in the presence of mechanical force. This project will test the hypothesis that a novel type of 'parasteric' inhibitor can directly open the FimH binding pocket even in the presence of mechanical force. The project will also test the hypothesis that FimH will be more effectively inhibited in physiological conditions by parasteric inhibitors than by conventional orthosteric or allosteric inhibitors. The following approaches will be used to obtain these goals. 1) The binding kinetics of FimH will be measured, both with and without mechanical force, in the presence of parasteric, orthosteric and allosteric inhibitory antibodies. 2) The structure and conformational dynamics of FimH will be determined in the presence of three types of antibodies using NMR, X-ray crystallography and atomistic structural simulations. 3) The effectiveness of the three types of antibodies will be compared, for preventing bacterial adhesion to uroepithelial cells, as well a urinary tract infections in mice. This work will provide rationale for FimH vaccine and inhibitor designs. This work will also provide rationale for developing inhibitors for many other adhesive receptors, which are attractive targets for therapeutic interventions for thrombotic and inflammatory diseases, cancer, and many other diseases.