UNS: Novel metabolic engineering strategies for complex oligosaccharide synthesis

UNS：复杂寡糖合成的新型代谢工程策略

• 批准号: 1509202
• 负责人: Ruizhen Chen
• 金额: $ 30.01万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-15 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1509202&HistoricalAwards=false
• 关键词: UNS; Novel; metabolic; engineering; strategies

1509202 Chen, Ruizhen Oligosaccharides are molecular recognition elements that play key roles in many vital biological processes such as cell growth and development,and host-pathogen interaction. Among many potential applications, oligosaccharides are particularly promising in diagnostics, vaccine, cancer therapy, prebiotics, and new antimicrobials. Unfortunately, these applications are hindered by the limited scalability and cost-effectiveness of current synthesis technologies. This project develops novel microbial biocatalysts for scalable and cost-effective synthesis of oligosaccharides. The success of this research will not only impact basic research efforts such as the understanding of glycan structure-function relationship, but also will impact broadly on their medical applications, including but not limited to diagnostic cancer diagnostics, vaccine development, prebiotics, and new antivirals.The goal of this research is to develop novel metabolic engineering strategies for complex oligosaccharide synthesis. Oligosaccharide biosynthesis is particularly difficult due to (i) a high cellular energy demand; (ii) the necessity to engage multiple sugar molecules; (iii) the complexity of the biochemical reaction network. These challenges accentuate as the target oligosaccharide becomes bigger and more complex. To overcome these challenges, a cellobiose-based metabolism that exploits energy-efficient phosphorolysis will be established to meet the high demand of cellular energy for synthesis. Using cellobiose based metabolism allows glucose, the best energy source, to be used without triggering its repression on the uptake of other sugars, thus enabling engineered biocatalysts to access multiple sugars as they are needed. The complexity of the biochemical network necessary for oligosaccharide synthesis is further addressed by breaking a complex reaction network into several small modules that are designed to be sequentially executed. Each module is activated at a time and for a duration dictated by a target oligosaccharide. This approach allows microbial biocatalysts to devote cellular resources (ATP, glycosyltransferase enzymes, and precursor pools) to only one glycosidic bond formation at a time so that it performs each glycosylation step efficiently. The methods used will include the expression of specific enzymes involved in oligosaccharide synthesis and the application of optimized feeding and bioprocessing strategies during synthesis of the desired compounds.This award by the Biotechnology and Biochemical Engineering Program of the CBET Division is co-funded by the Systems and Synthetic Biology Program of the Division of Molecular and Cellular Biology.

寡糖是一种分子识别元件，在许多重要的生物过程中起着关键作用，如细胞生长发育和宿主-病原体相互作用。在许多潜在的应用中，低聚糖在诊断、疫苗、癌症治疗、益生元和新型抗菌剂方面尤其有前景。不幸的是，这些应用受到当前合成技术有限的可扩展性和成本效益的阻碍。该项目开发了一种新型微生物生物催化剂，用于可扩展和经济高效地合成低聚糖。这项研究的成功不仅将影响糖基结构-功能关系等基础研究工作，而且将广泛影响其医学应用，包括但不限于诊断癌症诊断、疫苗开发、益生元和新的抗病毒药物。本研究的目的是为复杂低聚糖的合成开发新的代谢工程策略。低聚糖的生物合成特别困难，因为(i)细胞能量需求高；（ii）涉及多个糖分子的必要性；（三）生化反应网络的复杂性。当目标寡糖变得更大更复杂时，这些挑战就会加剧。为了克服这些挑战，将建立一种基于纤维素的代谢，利用高效的磷解来满足合成细胞能量的高需求。使用基于纤维素二糖的代谢可以使葡萄糖（最好的能量来源）在不触发其抑制其他糖的摄取的情况下被使用，从而使工程生物催化剂能够在需要时获得多种糖。通过将复杂的反应网络分解成几个设计成顺序执行的小模块，进一步解决了低聚糖合成所需的生化网络的复杂性。每个模块被激活的时间和持续时间由目标低聚糖决定。这种方法允许微生物生物催化剂一次只将细胞资源（ATP、糖基转移酶和前体池）用于一个糖苷键的形成，从而有效地执行每个糖基化步骤。所使用的方法将包括表达参与低聚糖合成的特定酶，以及在合成所需化合物期间应用优化的饲养和生物加工策略。该奖项由CBET部门的生物技术和生化工程项目颁发，由分子和细胞生物学部门的系统和合成生物学项目共同资助。