TWO REGULATORY ENZYMES OF DOLICHOL-LINKED GLYCOSYLATION

多醇连接糖基化的两种调节酶

• 批准号: 3290822
• 负责人: SHARON S KRAG
• 金额: $ 19.39万
• 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/3290822
• 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（研究者摘要）：寡聚核苷酸随附于 天冬酰胺残基在各种真核可溶性和 膜相关蛋白如酶、激素、受体 细胞外基质蛋白，质膜蛋白， 亚细胞器 N-连接糖蛋白的生物学特性不同， 功能和聚糖在该功能中的作用不同于蛋白质 到蛋白质。 在一些情况下，聚糖在蛋白质合成中起直接作用。 糖蛋白的生物活性，在其他情况下，聚糖影响 蛋白质的物理化学性质。 许多最初的步骤， 聚糖部分的复杂生物合成途径是常见的， 最后加工的结构。 最近的工作重点是了解 这一途径的调控。 使用的方法是一种生物化学方法， 一：表征和重建纯化酶的活性， 体外，并确定如何改变在个别酶水平， 体内影响整个糖基化途径的活性。 克拉格医生是 浓缩两种酶，UDP-N-乙酰葡糖胺：长链磷酸 N-乙酰葡糖胺-1-磷酸转移酶和甘露糖磷酸多萜醇 合成酶 转移酶是反应途径早期的酶， 合酶位于途径中的分支点。 的 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。 本提案中概述的研究将直接检验这一假设。