DOMAIN STRUCTURE AND MATRIX INTERACTIONS OF FIBRONECTIN

纤维连接蛋白(FN)是一种存在于血液和其他组织中的大而灵活的糖蛋白 体液和细胞外基质中。它与无数的 大分子包括几种细胞表面受体(整合素)和 介导多种类型的细胞与天然和人工的结合 表面。Fn的两条链中的每一条都含有大约30个 三种不同类型的内部同源图案或模块，每一种 由一个或两个外显子编码。这项研究的长期目标是 阐明FN中每个模块的结构和功能，以了解哪些模块 模块参与了多种相互作用以及哪些氨基 这些模块中的酸直接参与分子识别 流程。这将通过分离出更小的碎片来实现 通过蛋白质分解或重组技术，并表征其 差示扫描量热法测定热力学性质 荧光法。在这份提案中，我们的目标是首先确定每个 FN中独立折叠的结构域，并表征相互作用 相邻域。第二，我们将确定和描述 远端模块之间的分子内相互作用，并使用结果 开发对溶液中FN结构模型的约束。第三, 我们建议确定负责 纤维形成和基质形成过程中的分子间自缔合 集合。最后，我们建议研究FN与FN的相互作用 纤维蛋白原和凝血因子XIII。这项工作将有助于人们理解 基因外显子结构与结构域的关系 基因产品的结构，这些信息将对那些 针对特定基因的新型多功能模块化蛋白的生物工程研究 医疗应用。所获得的知识也将带来更好的 了解FN在多种生理过程中的作用 包括癌症、胚胎发生、造血、伤口愈合和 止血。

Fibronectin (Fn) is a large flexible glycoprotein found in blood and other body fluids and in the extracellular matrix. It interacts with numerous macromolecules including several cell-surface receptors (integrins) and mediates the binding of many types of cells to natural and artificial surfaces. Each of the two chains of Fn contains approximately 30 internally homologous motifs or modules of three different types, each encoded by one or two exons. The long range goals of this research are to elucidate the structure and function of each module in Fn, to know which modules are involved in the multiplicity of interactions and which amino acids within those modules participate directly in molecular recognition processes. This will be accomplished by isolating ever smaller fragments by proteolysis or recombinant techniques and characterizing their thermodynamic properties by differential scanning calorimetry and fluorescence methods. In this proposal we aim first to identify each independently folded domain in Fn and to characterize interactions between neighboring domains. Second, we will identify and characterize intramolecular interactions between distal modules and use the results to develop constraints on models of the structure of Fn in solution. Third, we propose to identify the modules that are responsible for the intermolecular self-associations involved in fibril formation and matrix assembly. Finally, we propose to investigate the interaction of FN with fibrin(ogen) and factor XIII. This work will assist efforts to understand the relationship between the exon structure of genes and the domain structure of gene products, information which will be useful to those attempting to bioengineer new multifunctional modular proteins for specific medical applications. The knowledge gained will also lead to a better understanding of the role of Fn in a variety of physiological processes including cancer, embryogenesis, hematopoiesis, wound healing and hemostasis.