MOLECULAR MECHANISMS OF ANNEXIN/MEMBRANE INTERACTIONS

膜联蛋白是一组同源的、依赖于钙离子的膜- 结合蛋白存在于各种各样的细胞和组织中。虽然 通常可溶，在有钙存在的情况下，这些蛋白质结合到酸性 膜中的脂类导致脂类的固定和隔离。 大多数家庭成员也会促进钙依赖 纯脂小泡或生物小泡的聚集和融合 膜。膜联蛋白可能构成许多不同的生物学基础。 细胞内外的过程，包括膜融合 在胞吐过程中，细胞骨架和膜之间的相互作用， 脂质组织和代谢的调节，离子跨膜通量 膜和血液凝固的调节。这项研究的目标是 是为了确定构成其基础的膜联蛋白的结构特征 它们与膜的相互作用，并利用这些信息来设计 这些蛋白质活性的抑制剂可应用于 以确定膜联蛋白在体内的功能。这些结构 几种膜联蛋白的含量将通过X射线衍射分析来确定。这个 结构数据将被用来设计膜联蛋白的突变 应该揭示特定的结构特征之间的关系 这些蛋白质具有一定的体外活性。特定的合并 将设计抑制剂，从合成肽开始 与关键蛋白质的N-末端区域相对应 用于控制它们的膜聚集活性。体外有效 抑制剂将被引入模型分泌细胞和成纤维细胞 确定它们对胞吐和胞内吞噬、细胞形态的影响 以及运动性和膜-细胞骨架组织。这些信息 了解抑制的结构、作用机制和模式 这些蛋白质可能允许开发药理手段来 调节膜联蛋白在激素释放，凝血， 或者细胞结构。

The annexins are a group of homologous, calcium-dependent, membrane- binding proteins present in a wide variety of cells and tissues. Although normally soluble, in the presence of calcium these proteins bind to acidic lipids in membranes leading to lipid immobilization and sequestration. Most members of the family will also promote the calcium-dependent aggregation and fusion of either pure lipid vesicles or biological membranes. The annexins may underlie a number of different biological processes both inside and outside of cells, including membrane fusion during exocytosis, interactions between the cytoskeleton and membranes, regulation of lipid organization and metabolism, ion fluxes across membranes, and regulation of blood coagulation. The goals of this study are to determine the structural features of the annexins that underlie their interactions with membranes, and to use this information to design inhibitors of the activities of these proteins that may be applied to cells to determine the functions of the annexins in vivo. The structures of several annexins will be determined by X-ray diffraction analysis. The structural data will be used to design mutations in the annexins that should reveal the relationship between specific structural features of these proteins and certain in vitro activities. Specific annexin inhibitors will be designed, beginning with synthetic peptides corresponding to the N-terminal regions of the proteins that are critical for control of their membrane-aggregating activity. Effective in vitro inhibitors will be introduced into model secretory cells and fibroblasts to determine their effects on exocytosis and endocytosis, cell morphology and motility, and membrane-cytoskeletal organization. The information gained about the structure, mechanism of action, and modes of inhibition of these proteins may permit the development of pharmacological means to regulate the annexins in disorders of hormone release, blood coagulation, or cell structure.