MOLECULAR CHARACTERIZATION OF S. MANSONI HEMOGLOBINASE

拟议工作的长期目标是理解 曼氏血吸虫蛋白水解酶基因的表达。蛋白酶是 被这种有机体用来入侵中间体和 确定的宿主和在其组织中的迁移 寄生虫的营养。拟议的工作将集中在 Smansoni蛋白酶与成虫同源，酸性，硫醇 用于降解宿主珠蛋白的血红蛋白酶。具体的 目的包括鉴定血吸虫硫醇蛋白水解酶基因 在寄生虫生活史中的表达和测定 蛋白酶基因的结构。主机对本机的响应 生产的血红蛋白酶和重组血红蛋白酶 还将对细菌进行评估。蛋白酶的性质研究 基因表达将涉及从鸡蛋中分离这些酶， 尾蚴和成虫。生化和免疫学方法将 用于确定酶的大体相同和不同之处 结构和衬底特性。的本地化 使用免疫组织学技术的体内蛋白酶也将被 已执行。编码这些蛋白水解物的cDNA的序列分析 酶将允许确定蛋白酶的同源性。 血吸虫硫醇蛋白水解酶编码基因的鉴定 将包括上游编码区和序列的测序 抄写的开始。宿主免疫学检查 对天然和重组血红蛋白酶的反应将 通过对近交系和近交系小鼠进行免疫，然后 血清抗体效价的酶联免疫吸附测定及检测 迟发性超敏反应。对蛋白酶基因的理解 表达可能导致对表达调控的了解 对血吸虫基因的了解，对 寄生虫生命周期中的潜在变化，以及 寄生的本质。此外，对蛋白酶的理解在 分子水平可能导致合理的疾病治疗方法 控制力。

The long-range goal of the proposed work is to understand protease gene expression in Schistosoma mansoni. Proteases are utilized by this organism for invasion of the intermediate and definitive hosts and migration through their tissues and for nutrition of the parasite. The proposed work will focus on Smansoni proteases homologus with an adult worm, acidic, thiol hemoglobinase used for degradation of host globin. The specific aims include characterization of schistosome thiol protease gene expression during the parasite's life cycle and determination of the structure of protease genes. Host responses against the native hemoglobinase and recombinant hemoglobinase produced in bacteria will also be evaluated. Characterization of protease gene expression will involve isolation of these enzymes from eggs, cercariae and adults. Biochemical nd immunologic methods will be used to determine gross similarities and differences in enzyme structures and substrate specificities. Localization of the proteases in vivo using immunohistologic techniques will also be performed. Sequencing of cDNAs which encode these proteolytic enzymes will allow determination of protease homologies. Characterization of genes encoding schistosome thiol proteases will include sequencing of coding regions and sequences upstream of the start of transcription. Examination of host immunological responses against the native and recombinant hemoglobinase will be made by immunization of inbred and outbred mice followed by ELISA measurements of antibody titers and examination of delayed hypersensitivity response. Understanding protease gene expression may lead to knowledge of the regulation of expression of schistosome genes, comprehension of mechanisms which underlie transformations during the parasite's life cycle, and the nature of parasitism. Moreover, understanding of proteases at the molecular level may lead to rational approaches to disease control.