BIOLOGY OF SIALIC ACID SUBSTITUTIONS

唾液酸取代的生物学

• 批准号: 3281140
• 负责人: AJIT P VARKI
• 金额: $ 26.15万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-08-01 至 1995-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3281140
• 关键词: acetylation; carbohydrate biosynthesis; complementary DNA; embryo /fetus; enzyme linked immunosorbent assay; enzyme mechanism; enzyme reconstitution; gangliosides; genetically modified animals; hydrolase; laboratory mouse; laboratory rabbit; laboratory rat; liver metabolism; molecular cloning; monoclonal antibody; neoplastic cell; protein purification; radiotracer; sialate; tissue /cell culture; tritium; western blottings

Many specific biological functions have been attributed to sialic acids. However, most studies of sialic acids do not take into account the diversity generated by modifications of the parent molecule, such as 0-acetylation of the side chain. During the prior funding period, we have developed new and sensitive methods for the analysis of modified sialic acids, identified some new and unexpected molecules, studied sialic acid:O-acetyltransferases from E.Coli., rat liver and human melanoma, identified and characterized sialic acid-specific 0-acetyl-esterases, studied the biosynthesis and turnover of the N-glycolyl group of sialic acids, and discovered a novel de-N-acetylation/re-N-acetylation reaction in melanoma gangliosides. Most recently, we have developed a novel approach to abrogate O-acetylation in the early mouse embryo, and in selected tissues of transgenic mice. In the upcoming grant period, we will focus our attention upon the following: 1. Purification, reconstitution and characterization of the rat liver Sialic Acid O-acetyltransferase(s). 2. Subcellular distribution of O-acetylated sialic acids, and the related enzymes in rat liver. 3. Purification, reconstitution and properties of human melanoma Sialic Acid O-acetyltransferase(s). 4. Mechanisms for de-N-acetylation and re-N-acetylation of sialic acids on gangliosides. 5. Molecular cloning of cDNAs encoding sialic acid specific O-acetyltransferase(s). 6. Abrogation of O-acetylation in the early mouse embryo. 7. Abrogation of O-acetylation in selected tissues of transgenic mice. In the long run, these studies will help us to understand the biological roles of sialic acids and their modifications in health and disease. Our findings to date implicate these molecules in a variety of important roles, including protection from microbial organisms on mucosal surfaces, the modulation of complement activation, the expression of oncofetal antigens in various tumors, and the regulation of cell-cell interaction during the development of certain organs.

许多特定的生物学功能已被归因于 唾液酸 然而，大多数唾液酸的研究没有考虑到 考虑到母体分子修饰产生的多样性， 例如侧链的O-乙酰化。 在前期融资中 在此期间，我们开发了新的和敏感的分析方法， 修饰的唾液酸，发现了一些新的和意想不到的分子， 研究了来自大肠杆菌的唾液酸：O-乙酰基转移酶，大鼠肝脏和 人黑色素瘤，经鉴定和表征的唾液酸特异性 0-乙酰酯酶，研究了 唾液酸的N-羟乙酰基，并发现了一种新的 黑色素瘤神经节苷脂中的去N-乙酰化/再N-乙酰化反应。 最近，我们开发了一种新的方法来废除 在小鼠早期胚胎中的O-乙酰化， 转基因小鼠 在即将到来的资助期内，我们将专注于 注意以下事项： 1.大鼠肝脏的纯化、重建和表征 唾液酸O-乙酰转移酶。 2. O-乙酰化唾液酸的亚细胞分布及其相关的 大鼠肝脏中的酶。 3.人黑色素瘤唾液酸的纯化、重组及性质研究 酸性O-乙酰转移酶。 4.唾液酸的脱N-乙酰化和再N-乙酰化机理 神经节苷脂 5.编码唾液酸特异性的cDNA的分子克隆 O-乙酰转移酶。 6.小鼠早期胚胎中O-乙酰化的消除。 7.转基因小鼠选定组织中O-乙酰化的消除。 从长远来看，这些研究将有助于我们了解 唾液酸的生物学作用及其在健康和 疾病 迄今为止，我们的研究结果表明，这些分子参与了多种 重要作用，包括保护粘膜免受微生物的侵害 表面，补体激活的调节， 各种肿瘤中的癌胚抗原，以及细胞-细胞免疫调节 在某些器官发育过程中的相互作用。