SERPIN GENETICS STRUCTURE AND FUNCTION

这个项目的长期目标是了解丝氨酸(丝氨酸蛋白酶 抑制剂)结构/功能关系通过研究自然发生 并在体外产生了蛇毒突变体。提高了对蛇纹线的理解 结构/功能原则将导致更有效的治疗 血栓、出血、通透性和与以下疾病相关的肺部疾病 丝氨酸/蛋白水解酶失衡。 具体目标1是确定为什么P12区的扰动改变了 从抑制剂到底物的丝线。P12区域位于 反应中心的氨基末端侧。对自然发生的分析 丝氨酸突变体表明P12区域参与了决定 丝氨酸是其目标蛋白酶的抑制物还是底物(S)。 P12区在决定丝氨酸中的作用模型 提出了抑制剂/底物的状态，并将通过研究 正常蛇体和P12区突变体与蛋白酶的相互作用。 具体目标2是确定为什么ATIII P11‘区域的完整性是 获得正常循环水平的蛇针所需的。P11‘区 位于反应中心的羧基末端侧。自然而然 在P11‘区有病变的出现的蛇链突变体出现在 循环中的水平极低，这表明它是 对于确定细胞内的降解、分泌或清除很重要 费率。这些参数将在表达正常蛇链的细胞中进行研究 和PLL‘区突变，以阐明PLL’区的作用 在确定循环中的蛇纹针水平方面起到了作用。 具体目标3阐明抗凝血酶III的结构基础 肝素辅因子活性。ATIII肝素辅因子活性的模型为 建议并将通过使抗凝血酶突变体具有明确的 结构异常及其功能特性的研究。一个 对该模型的进一步测试将涉及尝试将肝素 抗凝血酶III对另一种丝氨酸的辅因子特性 1-抗胰蛋白酶。

The long term goal of this project is to understand serpin (serine protease inhibitor) structure/function relationships by studying naturally occurring and in vitro generated serpin mutants. Improved understanding of serpin structure/function principles will lead to more effective treatment for thrombosis, bleeding, permeability and pulmonary disorders associated with serpin/protease imbalances. Specific Aim 1 is to determine why perturbations of the P12 region change a serpin from an inhibitor to a substrate. The P12 region is located on the amino terminal side of the reactive center. Analysis of naturally occurring serpin mutants indicates that the P12 region is involved in determining whether a serpin is an inhibitor or a substrate for its target protease(s). A model for the role of the P12 region in determining serpin inhibitor/substrate status is proposed and will be tested by studying the interactions of normal serpins and P12 region mutants with proteases. Specific Aim 2 is to determine why integrity of the ATIII P11' region is required to obtain normal circulating levels of a serpin. The P11' region is located on the carboxy terminal side of the reactive center. Naturally occurring serpin mutants with lesions in the P11' region are present at extremely reduced levels in the circulation, suggesting that it is important for determining intracellular degradation, secretion or clearance rates. These parameters will be studied in cells expressing normal serpins and Pll' region mutants in order to elucidate the role the Pll' region plays in determining circulating serpin levels. Specific Aim 3 is to elucidate the structural basis of antithrombin III heparin cofactor activity. A model for ATIII heparin cofactor activity is proposed and will be tested by making antithrombin mutants with defined structural abnormalities and studying their functional properties. A further test of the model will involve trying to transfer the heparin cofactor property of antithrombin III to another serpin, such as alpha 1-antitrypsin.