TWO REGULATORY ENZYMES OF DOLICHOL-LINKED GLYCOSYLATION

多醇连接糖基化的两种调节酶

• 批准号: 3290821
• 负责人: SHARON S KRAG
• 金额: $ 18.51万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-12-01 至 1994-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3290821
• 关键词: antibody; dolichol; enzyme mechanism; enzyme reconstitution; glycoprotein biosynthesis; glycosylation; glycosyltransferase; immunoprecipitation; laboratory rabbit; mannose; membrane proteins; messenger RNA; nucleic acid sequence; oligosaccharides; phosphotransferases; posttranslational modifications; protein purification; tissue /cell culture; tunicamycin

DESCRIPTION (Investigator's Abstract): Oligosaccharides are attached to asparagine residues in a wide variety of eukaryotic soluble and membrane-associated proteins such as enzymes, hormones, receptors, extracellular matrix proteins, and the proteins of the plasma membrane and subcellular organelles. N-linked glycoproteins vary as to their biological function and the role of the glycan in that function differs from protein to protein. In some cases, the glycan plays a direct role in the glycoprotein's biological activity and in other cases the glycan affects the protein's physicochemical properties. Many of the initial steps in the complex biosynthetic pathway of the glycan moiety are common regardless of the final processed structure. Recent work has focused on understanding the regulation of this pathway. The approach to be used is a biochemical one: to characterize and reconstitute the activity of purified enzymes in vitro and to determine how alterations in an individual enzyme level in vivo effects the activity of the entire glycosylation pathway. Dr. Krag is concentrating on two enzymes, UDP-N-acetylglucosamine:dolichyl phosphate N-acetylglucosamine-1-phosphate transferase and mannosylphosphoryldolichol synthase. The transferase is an enzyme early in the reaction pathway and the synthase is positioned at a branch point in the pathway. The hypothesis is that both these enzymes are important regulatory enzymes in the biosynthetic pathway of the glucose moiety of N-linked glycoproteins. The studies outlined in this proposal will directly test this hypothesis.

描述（研究者的摘要）：寡糖附在 多种真核可溶性中的天冬酰胺残留物和 膜相关蛋白，例如酶，激素，受体， 细胞外基质蛋白，以及质膜的蛋白质和 亚细胞细胞器。 N连接的糖蛋白因其生物学而变化 糖在该功能中的功能和作用与蛋白质不同 蛋白质。 在某些情况下，聚糖在 糖蛋白的生物活性，在其他情况下，聚糖会影响 蛋白质的物理化学特性。 许多初始步骤 糖基部分的复杂生物合成途径是常见的 最终处理的结构。 最近的工作重点是理解 该途径的调节。 要使用的方法是生化 一个：表征和重建纯化酶的活性 体外并确定单个酶水平的改变 体内影响整个糖基化途径的活性。 Krag博士是 浓缩两种酶UDP-N-乙酰葡萄糖：多乙基磷酸盐 N-乙酰基葡萄糖胺1-磷酸转移酶和甘露磷酰磷酸二硫醇 合酶。 转移酶是反应途径早期的酶， 合成酶位于路径中的分支点。 这 假设这两种酶都是重要的调节酶 N-连接糖蛋白的葡萄糖部分的生物合成途径。 该提案中概述的研究将直接检验该假设。