Trypansome Surface Glycoproteins

锥虫表面糖蛋白

• 批准号: 6469932
• 负责人: PAUL T ENGLUND
• 金额: $ 40.88万
• 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 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6469932
• 关键词: Trypanosoma; Trypanosoma brucei rhodesiense; acyl carrier protein; enzyme activity; fatty acid biosynthesis; fatty acid synthase; fatty acylation; gel electrophoresis; genetic screening; glycoproteins; glycosylation; green fluorescent proteins; host organism interaction; mass spectrometry; matrix assisted laser desorption ionization; membrane proteins; microorganism culture; microorganism genetics; microorganism metabolism; molecular cloning; myristates; protozoal antigen; transfection

DESCRIPTION: (provided by the applicant): The goal of this project is to study the surface glycoproteins of the African trypanosome, Trypanosoma brucei. The variant surface glycoprotein (VSG) 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. Procyclin is the unusual protein that covers the surface of the insect form of T. brucei. Our studies focus mainly on the glycosyl groups of these proteins, especially the GPI anchors. The VSG GPI is unusual in that it contains the fatty acid myristate. Because trypanosomes have massive amounts of VSG they need large amounts of myristate, which is a rare fatty acid in the host's bloodstream. In fact, it appeared that there was not enough myristate in the serum to provide sufficient myristate for GPI anchors. Only recently our lab found that trypanosomes actually synthesize myristate, overturning the 30-year-old belief that they cannot make fatty acids. The first specific aim is to study the mechanism of myristate synthesis. Although trypanosomes are eukaryotes, the fatty acid synthetic machinery resembles that of prokaryotes. Of special importance will be studies aimed at testing inhibitors of fatty acid synthesis as candidate anti-trypanosomal drugs. The second specific aim concerns the mechanism of GPI anchoring and protein glycosylation. Previous studies along these lines have been biochemical, but the proposed approach involves genetics. These studies will involve the powerful new technique of RNA interference (RNAi) that selectively silences trypanosome genes. The third aim involves the mechanism of GPI myristoylation, by remodeling reactions. These experiments involve attempts to purify and study a myristoyl transferase, using biochemical and genetic techniques.

描述：（由申请人提供）：该项目的目的是学习 非洲锥虫的表面糖蛋白Brucei锥虫。这 血液形式的寄生虫的变体表面糖蛋白（VSG）保护 宿主免疫系统识别的地下结构。交换 从一个VSG到另一种VSG的表达（抗原变异）使寄生虫可以 在宿主的血液中生存。 procyclin是覆盖的异常蛋白质 昆虫的表面t。brucei。我们的研究主要关注 这些蛋白质的糖基团，尤其是GPI锚固剂。 VSG GPI是 不寻常的是，它含有脂肪酸肉豆蔻酸酯。 因为锥虫具有大量的VSG，因此需要大量 肉豆蔻酸酯，这是宿主血液中一种罕见的脂肪酸。实际上，它 看来血清中没有足够的肉芽菌来提供足够的 GPI锚点的肉豆蔻。直到最近我们的实验室才发现锥虫 实际上综合了肉豆蔻，推翻了30岁的信念 无法制作脂肪酸。第一个具体目的是研究 肉豆蔻酸酯的合成。尽管锥虫是真核生物，但脂肪酸 合成机械类似于原核生物。特别重要的是 旨在测试脂肪酸合成抑制剂作为候选者的研究 抗肉毒体药物。第二个特定目的涉及GPI的机制 锚定和蛋白质糖基化。以前沿着这些线的研究具有 一直是生化的，但是提出的方法涉及遗传学。这些研究 将涉及强大的RNA干扰新技术（RNAi） 有选择地沉默锥体基因。第三个目标涉及 GPI肉豆蔻酰化，通过重塑反应。这些实验涉及尝试 使用生化和遗传净化和研究肉豆蔻酰转移酶 技术。