Interactions and Reactions of Carbohydrates and Proteins

碳水化合物和蛋白质的相互作用和反应

• 批准号: 2551-2013
• 负责人: Withers, Stephen
• 金额: $ 11.66万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=632765
• 关键词: Interactions; Reactions; Carbohydrates; Proteins

The enzymes involved in the hydrolysis of glycosidic bonds (glycosidases) play a range of important biological roles, ranging from the degradation of polysaccharides such as starch and cellulose in digestive processes to the exquisitely selective 'trimming' of glycoproteins required for individual cells to interact with each other and with their environment. A detailed understanding of how these highly efficient catalysts (they accelerate reactions some billion-billion fold) work is valuable, not only in understanding catalysis itself, and engineering these enzymes to carry out novel reactions, but also in the design and synthesis of specific inhibitors to control cellular processes, thus possibly as therapeutics. This proposal comprises three parts. In the first part we propose mechanistic studies to unravel details of a novel mechanism that we have been studying from an enzyme from a pathogenic bacterium: this could lead to inhibitors to control infection. We also propose detailed mechanistic studies to understand how enzymes catalyze reactions so effectively and how they control their pH optima. In the second part, triggered by recent findings of how Mother Nature makes sugar mimetics, we propose to explore whether other classes of enzyme can carry out similar reactions. Finally we propose a methodology to "retrain" glycosyltransferases, enzymes that make useful sugar derivatives, to do so using inexpensive starting materials. To do this we shall harness the tools of genetics, microbiology, cell biology and analytical and organic chemistry in a process known as "directed evolution". This could lead to improved manufacturing strategies for sugar-based therapeutics and other products.

参与糖苷键水解的酶（糖苷酶）发挥着一系列重要的生物学作用，从消化过程中淀粉和纤维素等多糖的降解，到单个细胞相互作用以及与环境相互作用所需的糖蛋白的精细选择性“修剪”。详细了解这些高效催化剂（它们将反应加速数十亿亿倍）是如何工作的是有价值的，不仅在理解催化本身，设计这些酶来进行新的反应，而且在设计和合成特定抑制剂来控制细胞过程，因此可能作为治疗方法。本建议由三部分组成。在第一部分中，我们提出了机制研究，以揭示我们从一种致病细菌的酶中研究的新机制的细节：这可能导致控制感染的抑制剂。我们还提出了详细的机制研究，以了解酶如何如此有效地催化反应以及它们如何控制其最佳pH值。在第二部分中，由于最近发现了大自然如何制造糖模拟物，我们提议探索其他种类的酶是否可以进行类似的反应。最后，我们提出了一种“再训练”糖基转移酶的方法，这种酶可以制造有用的糖衍生物，使用廉价的起始材料。为此，我们将在一个被称为“定向进化”的过程中利用遗传学、微生物学、细胞生物学、分析化学和有机化学的工具。这可能会改善糖基治疗药物和其他产品的生产策略。