MOLECULAR MECHANISMS OF ANNEXIN/MEMBRANE INTERACTIONS

膜联蛋白是一组同源的、钙依赖的、膜- 存在于多种细胞和组织中的结合蛋白。虽然 通常可溶，在钙存在下，这些蛋白质结合到酸性 膜中的脂质导致脂质固定和隔离。 大多数家庭成员也会促进钙依赖 纯脂质囊泡或生物囊泡的聚集和融合 膜。 膜联蛋白可能是许多不同生物学特性的基础。 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， 调节脂质组织和代谢，离子通量， 膜和调节血液凝固。 本研究的目标 是为了确定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， 细胞，以确定膜联蛋白在体内的功能。 的结构 几种膜联蛋白的含量将通过X射线衍射分析来确定。 的 结构数据将用于设计膜联蛋白中的突变， 应该揭示的具体结构特征之间的关系， 这些蛋白质和某些体外活性。特异性膜联蛋白 将设计抑制剂，从合成肽开始， 对应于蛋白质的N-末端区域， 以控制它们的膜聚集活性。有效的体外 将抑制剂引入模型分泌细胞和成纤维细胞中 为了确定它们对胞吐作用和胞吞作用、细胞形态 和运动性，以及膜细胞骨架组织。 的信息 获得了关于结构，作用机制和抑制模式的信息 这些蛋白质可能允许开发药理学手段， 调节激素释放，血液凝固， 或细胞结构。

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.