BIOLOGY OF GIARDIA--ROLE OF CARBOHYDRATE RESIDUES

贾第鞭毛虫生物学——碳水化合物残基的作用

• 批准号: 3454930
• 负责人: Honorine D Ward
• 金额: $ 10.53万
• 依托单位: TUFTS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-08-01 至 1995-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3454930
• 关键词: Giardia; N acetylgalactosamine; autoradiography; carbohydrate biosynthesis; carbohydrate structure; cell differentiation; chitin; developmental genetics; disease /disorder prevention /control; electron microscopy; enzyme structure; gas chromatography mass spectrometry; gel electrophoresis; gel filtration chromatography; gene expression; giardiasis; high performance liquid chromatography; human subject; immunoprecipitation; intracellular parasitism; laboratory mouse; ligase; microorganism genetics; molecular genetics; monoclonal antibody; protein biosynthesis; protein purification; protein structure function; protozoal cyst

Giardia lamblia is a significant cause of diarrheal disease worldwide which is perpetuated by the infective cyst form of the parasite. The mechanisms underlying the process of differentiation from trophozoite to cyst are poorly understood. The overall purpose of this project is to decipher the biochemical and molecular events involved in this process, focusing on structure and function of carbohydrate moieties in both trophozoite and cyst. The specific aims of this proposal are directed at a) elucidating structural and biosynthetic aspects of N-acetyl-glucosamine containing carbohydrate moieties which have been identified as chitin in cyst walls as well as linked to glycoproteins in trophozoites and cysts and b) relating these aspects to the biological role of these moieties in differentiation of the parasite. The first aim is to determine the structure and linkage of the GIcNAc residues in trophozoite and cyst glycoproteins with the long term objective of studying their biosynthesis and ascertaining whether they serve as precursor moieties for chitin synthesis which is a key event in differentiation. The second aim is to characterize, purify and produce antibodies to chitin synthase which is a developmentally regulated enzyme involved in the biosynthesis of chitin. These studies will facilitate the long term objective of delineating genetic control of differentiation at the molecular level by identifying cyst and trophozoite specific genes encoding developmentally regulated proteins. The third aim is to determine the subcellular localization of chitin and chitin precursors as well as the N-acetyl-glucosamine containing glycoproteins at the ultrastructural level. The last aim is to relate the findings obtained at the structural and biochemical level to growth and differentiation of the parasite in vitro as well as in vivo in animal models of giardiasis. The ultimate goal is to design strategies to arrest differentiation, interrupt the life cycle of the parasite and control spread of the disease.

贾第鞭毛虫兰维利亚是全球腹泻病的重要原因， 由寄生虫的感染性囊肿形式永久存在。机制 从滋养体到囊肿的分化过程的基础是 理解不佳。该项目的总体目的是破译 此过程中涉及的生化和分子事件，重点是 在滋养体和碳水化合物中的结构和功能和功能 囊肿。 该提案的具体目的是针对a）阐明的 N-乙酰基葡萄糖的结构和生物合成方面，含有 碳水化合物部分在囊肿壁上被鉴定为几丁质的部分 以及与滋养体和囊肿中的糖蛋白相关的以及b） 这些方面这些部分在分化中的生物学作用 寄生虫。第一个目的是确定 滋养体和囊肿糖蛋白中的GICNAC残基与长 研究其生物合成并确定它们是否的术语目标 用作甲丁蛋白合成的前体部分，这是一个关键事件 分化。第二个目的是表征，净化和生产 甲壳质合酶的抗体，这是一种发育调节的酶 参与几丁质的生物合成。这些研究将促进 划定分化遗传控制的长期目标 分子水平通过鉴定囊肿和滋养体特异性基因 编码发育调节的蛋白质。第三个目的是确定 几丁质和几丁质前体的亚细胞定位以及 在超微结构水平上含有糖蛋白的N-乙酰基葡萄糖。 最后一个目的是关联结构上获得的发现， 寄生虫在体外的生长和分化的生化水平 以及在贾第鞭毛疾病动物模型中的体内。最终目标是 逮捕差异化，中断生命周期的设计策略 疾病的寄生虫传播。