Applications of Click Chemistry in Glycobiology

细胞表面聚糖是细胞间相互作用的主要决定因素。细胞表面糖基化的变化 标志着癌症和炎症的开始。在细胞内，它们可以调节转录， as protein蛋白trafficking贩运.然而，对聚糖功能的分子基础的描述进展一直是 相当慢。这部分是由于聚糖的生物合成与其他生物聚合物不同， 模板驱动也不在直接转录控制下。因此，传统的遗传和生化 用于阐明聚糖功能及其与疾病的相关性的方法已经产生了有限的信息。 这个项目的长期目标是实现点击化学-一套强大的，可靠的和选择性的 反应-作为糖生物学基础研究的通用工具。 凭借从K99阶段获得的经验和知识，我将在两个新的领域扩展我的研究。 在下一个授予期（ROO）的方向。目标1是发现/开发聚糖的小分子抑制剂 使用酶模板原位点击化学的生物合成和加工酶。为了证明原则，我 选择0-β-N-乙酰葡糖氨基转移酶（OGT）作为第一靶点。我计划开发片段库 将被筛选出OGT的自组装抑制剂。考虑到过量的0-GlcNAc 长期的高血糖症，这反过来又触发胰岛素抵抗，化合物 开发可能在糖尿病治疗中有应用。目的2是阻断聚糖生物合成途径， 带有生物正交官能团的合成非天然底物，如叠氮化物和炔。在 同时，我还将开发基于点击化学的新的选择性反应，用于随后的检测。 活细胞

Cell surface glycans are major determinants of cell-cell interactions. Changes In cell surface glycosylation mark the onset of cancer and inflammation. Inside the cell, they can regulate transcription, translation as well as protein trafficking. Progress toward delineating the molecular basis of glycan function, however, has been rather slow. This is partly due to the fact that the biosynthesis of glycans, unlike other biopolymers, is neither template-driven nor under direct transcriptional control. Therefore, conventional genetic and biochemical approaches for elucidating glycan function, and its relevance to disease, have yielded limited information. The long term goal of this project is to implement click chemistry-a set of powerful, reliable and selective reactions-as a general tool for fundamental studies of glycobiology. With the experience and knowledge gained from the K99 phase, I will expand my research in two new directions in the next granting period (ROO). Aim 1 is to discover/develop small molecule inhibitors of glycan biosynthetic and processing enzymes using enzyme-templated in situ click chemistry. For proof of principle, I chose 0-beta-N-acetylglucosamlnyl-transferase (OGT) as the first target. I plan to develop fragment libraries that will be screened for self-assembled inhibitors of OGT. Given the correlation of excessive 0-GlcNAc modification with prolonged hyperglycemia, which in turn triggers insulin resistance, the compounds developed may have applications in diabetes therapy. Aim 2 is to intercept glycan biosynthetic pathways with synthetic unnatural substrates bearing bioorthogonal functional groups, such as azides and alkynes. In parallel, I will also develop new selective reactions based on click chemistry for their subsequent detection in live cells.