TRYPANOSOME SURFACE GLYCOPROTEINS

锥虫表面糖蛋白

• 批准号: 2886463
• 负责人: PAUL T ENGLUND
• 金额: $ 31.96万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-05-01 至 2002-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2886463
• 关键词: Trypanosoma; Xenopus oocyte; electron microscopy; enzyme activity; fatty acid metabolism; fatty acid synthase; fatty acylation; gene complementation; glycoproteins; glycosylation; host organism interaction; lipid biosynthesis; membrane proteins; microorganism culture; microorganism genetics; microorganism metabolism; molecular cloning; myristates; protein purification; protozoal antigen; surface antigens; transfection; yeasts

The goal of this project is to study the surface glycoproteins of the African trypanosome, Trypanosoma brucei. VSG, the major surface protein of bloodstream form parasites, protects subsurface structures from recognition by the host immune system. Switching expression from one VSG to another (antigenic variation) allows the parasite to survive in the host's bloodstream. PARP (procyclic acidic repetitive protein) is an unusual protein which overs the surface of the insect form of T. brucei. Our studies focus mainly on the glycosyl groups of these proteins, with most studies on the GPI anchor of VSG. Since myristate is an important component of the VSG anchor, the first specific aim will be to study the mechanism by which myristate is taken up by the cell and processed. This is a problem for the parasite, as it cannot synthesize myristate and it lives in an environment where this fatty acid is in low concentration. In these studies we will purify and characterize myristoyl-CoA synthases and we shall look for myristate transporters and binding proteins. We shall use biochemical approaches as well as yeast genetics to find these proteins or their genes. The second specific aim will be to study GPI biosynthesis and catabolism, with most emphasis placed on the mechanism of GPI myristoylation in bloodstream forms. In the third specific aim we will characterize T. brucei glycosylation mutants. We have already isolated mutants of the procyclic stage of T. brucei, which have an altered PARP, and we are studying whether the mutations affect N-linked glycosylation or the GPI structure. We will attempt to clone the mutant gene by functional complementation

该项目的目的是研究该项目的表面糖蛋白 非洲锥虫，布鲁氏锥虫。 VSG，主要的表面蛋白 血液形成寄生虫，保护地下结构免受 宿主免疫系统的识别。 从一个VSG切换表达式 到另一种（抗原变异）允许寄生虫在 宿主的血液。 PARP（Procyclic酸性重复蛋白）是 不寻常的蛋白质，它超过了昆虫的t. brucei昆虫表面。 我们的研究主要集中于这些蛋白质的糖基团， 大多数关于VSG GPI锚的研究。 由于Myristate是VSG锚的重要组成部分，因此 具体目的是研究采取肉豆蔻酸酯的机制 通过细胞加工并处理。 这是寄生虫的问题 无法综合肉豆蔻质，它生活在一个环境中 脂肪酸浓度低。 在这些研究中，我们将净化并 特征是Myristoyl-COA合酶，我们将寻找肉豆蔻酸盐 转运蛋白和结合蛋白。 我们将使用生化方法 以及酵母遗传学，以找到这些蛋白质或其基因。 这 第二个具体目的是研究GPI生物合成和分解代谢， 最重视GPI Myristoylation的机制 血液形式。 在第三个特定目标中，我们将表征T。 brucei糖基化突变体。 我们已经隔离了 T. Brucei的Procyclic阶段，其PARP改变了，我们是 研究突变是影响N连接的糖基化还是GPI 结构。 我们将尝试通过功能来克隆突变基因 互补