C1 INHIBITOR GENE AND HEREDITARY ANGIONEUROTIC EDEMA

描述(改编自研究人员摘要)：C1INH是一种 丝氨酸蛋白酶抑制剂(丝氨酸蛋白酶抑制剂)，调节经典的 补体途径与失活的接触(激动素)系统 C1r、C1s、血浆激肽释放酶和凝血因子XII。C1INH的杂合性 C1INH蛋白缺乏或表达异常会导致 遗传性血管水肿(HAE)。在第一个目标中，将建立HAE的动物模型 利用基因打靶技术开发的。我们假设C1INH-/-小鼠 将不会存活，C1NH+/-小鼠将出现血管水肿。要测试 认为血管水肿是通过接触系统激活来调节的假说是有缺陷的 小鼠将用靶标改变的重组C1INH突变体重组 将与缓激肽受体2(Bk2R)交配 以及C2缺陷小鼠。来检验这样一种假设，即抑制 缓激肽干预症状，对HAE小鼠进行治疗 Bk2R拮抗剂。雄激素在血管水肿中的作用机制也将 被分析。为了检验接触系统在 感染性休克的发病机制及C1INH+/-小鼠对内毒素的易感性 震惊将会被确定。选择性抑制的C1INH蛋白输注 活动将确定补充系统和联系系统的作用。这个 第二个目标是结构-功能分析。要测试 假设稳定的络合物形成需要广泛插入 反应中心环(RCL)变成β-折叠A，RCL突变体和突变体 改变A片的稳定性将被检查。来检验这一假设 RCL内外的位置决定靶标蛋白酶的专一性，P2 α1-抗胰蛋白酶：C1INH的突变、远端环突变和非RCL突变 嵌合体将受到考验。来检验氨基末端被截断的假设 C1INH更有效地抑制表面相关蛋白酶，其能力 抑制免疫复合体介导的补体激活，灭活高 分子量激肽原(HK)结合激肽释放酶和表面结合因子XIIa 将会被检查。C1INH与其他化合物的结构比较 Serpins，重组截短的C1INH将被结晶。除了……之外 C1INH的生物学作用的定义及其功能的表征， 这些研究还可能导致改善HAE和其他疾病的治疗 补体或接触系统的激活起到了作用。

DESCRIPTION (Adapted from investigator's abstract): C1 inhibitor (C1INH) is a serine proteinase inhibitor (serpin) that regulates activation of the classical complement pathway and the contact (kinin-generating) systems by inactivation of C1r, C1s, plasma kallikrein and factor XII. Heterozygosity for C1INH deficiency or for expression of a dysfunctional C1INH protein results in hereditary angioedema (HAE). In the first Aim, an animal model for HAE will be developed using gene targeting technology. We hypothesize that C1INH-/-mice will not survive and that C1NH +/- mice will develop angioedema. To test the hypothesis that angioedema is mediated via contact system activation, deficient mice will be reconstituted with recombinant C1INH mutants with altered target proteinase specificities, and will be mated with bradykinin receptor 2 (Bk2R) and with C2 deficient mice. To test the hypothesis that inhibition of bradykinin will interfere with symptoms, the HAE mice will the treated with Bk2R antagonists. The mechanism of action of androgens in angioedema also will be analyzed. To test the hypothesis that the contact system plays a role in the pathogenesis of septic shock, the susceptibility of C1INH +/- mice to endotoxin shock will be determined. Infusions of C1INH proteins with selective inhibitory activities will define the roles of the complement and contact systems. The second Aim is directed toward structure-function analyses. To test the hypothesis that stable complex formation requires extensive insertion of the reactive center loop (RCL) into beta sheet A, RCL mutants and mutants that alter the stability of sheet A will be examined. To test the hypothesis that sites within and outside the RCL determine target protease specificity, P2 mutants, distal loop mutants, and non-RCL mutants in alpha1-antitrypsin:C1INH chimeras will be tested. To test the hypothesis that amino terminal-truncated C1INH more efficiently inhibits surface associated proteases, its ability to inhibit immune complex-mediated complement activation, and inactivate high molecular weight kininogen (HK)-bound kallikrein and surface-bound factor XIIa will be examined. To compare and contrast the structure of C1INH with other serpins, recombinant truncated C1INH will be crystallized. In addition to definition of the biologic roles of C1INH and characterization of its function, these studies also may lead to improved therapy of HAE and of other diseases in which activation of the complement or contact systems plays a role.