Toward Artificial Enzyme Analogues for Cellulose Hydrolysis Using High-throughput Screening

利用高通量筛选开发用于纤维素水解的人工酶类似物

• 批准号: 1033017
• 负责人: Daeyeon Lee
• 金额: $ 30.28万
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1033017&HistoricalAwards=false
• 关键词: Toward; Artificial; Enzyme; Analogues; Cellulose

1033017LeeIntellectual MeritsA sustainable and environmentally friendly source of ethanol for transportation fuel is cellulose, which is the major component of lignocellulosic plant biomass. Hydrolysis of cellulose generates glucose, which can be fermented to ethanol. However, in general, the hydrolysis of cellulose is a difficult process, and is currently the rate-limiting step in the cellulose-to-ethanol conversion. Cellulase enzymes with very specific catalytic structures are capable of efficient cellulose hydrolysis without byproduct formation. However, enzymes are relatively slow, thermally unstable, and expensive, as they must be biologically produced are not readily reusable. The proposed research will develop and understand the function of artificial enzyme analogues that can hydrolyze cellulose and its subunits. Artificial enzyme structures will be created by molecular imprinting of cellulose oligomers onto organic-inorganic hybrid solid catalyst supports based on sol-gel methods. This strategy has the potential to combine the efficiency and specificity of protein-based enzymes with the robustness and cost effectiveness of heterogeneous solid catalysts.In the proposed research, artificial enzyme analogues for hydrolysis of cello-oligomers and cellulose will be generated based on a molecular-imprinting sol-gel technique combined with a high-throughput synthesis and screening method. Molecular cavities generated by the imprinting process will provide specific binding domains for sub-units of cellulose as well as solid acid sites required for hydrolysis of glycosidic bonds. To potentially enhance substrate hydrolysis and promote induced fit between the molecularly imprinted catalyst and substrate, the flexibility of the sol-gel catalysts will be tuned by adding organo-silanes to the sol-gel matrix. It is hypothesized that the specificity of the molecularly-imprinted catalysts would hinder side reactions that lead to degradation of glucose, which is a major problem with conventional solid-acid catalysts. The high throughput method will be able to screen a large number (~10,000) of synthesis parameters to optimize the composition and structure of the molecularly-imprinted catalysts.Broader ImpactsThe proposed education and outreach activities are designed to stimulate student interest in biomass energy and fundamental ideas in science and engineering. Undergraduate students from underrepresented groups recruited through the Louise Stokes Alliance for Minority Participation (AMP) Summer Undergraduate Research Program will be given opportunities to participate in the research. As part of the outreach plan, the PI will work with a local cable access TV station to develop programming on the current state of energy landscape and the importance of developing renewable energy technologies. This scientific program will be aired throughout the Philadelphia metro area.

纤维素是一种可持续和环境友好的运输燃料乙醇来源，它是木质纤维素植物生物质的主要成分。纤维素水解产生葡萄糖，葡萄糖可以发酵成乙醇。然而，一般来说，纤维素的水解是一个困难的过程，目前是纤维素转化为乙醇的限速步骤。纤维素酶具有非常特殊的催化结构，能够有效地水解纤维素而不产生副产物。然而，酶是相对缓慢、热不稳定和昂贵的，因为它们必须是生物生产的，不易重复使用。提出的研究将开发和了解可以水解纤维素及其亚基的人工酶类似物的功能。基于溶胶-凝胶法将纤维素低聚物分子印迹于有机-无机杂化固体催化剂载体上，形成人工酶结构。这种策略有可能将蛋白质酶的效率和特异性与异相固体催化剂的稳健性和成本效益结合起来。在本研究中，将基于分子印迹溶胶-凝胶技术结合高通量合成和筛选方法，生成用于水解纤维素低聚物和纤维素的人工酶类似物。印迹过程产生的分子空腔将为纤维素亚基提供特定的结合域，以及水解糖苷键所需的固体酸位点。为了潜在地促进底物水解和促进分子印迹催化剂与底物之间的诱导配合，将通过在溶胶-凝胶基质中添加有机硅烷来调节溶胶-凝胶催化剂的灵活性。假设分子印迹催化剂的特异性会阻碍导致葡萄糖降解的副反应，这是传统固体酸催化剂的一个主要问题。高通量方法将能够筛选大量（~10,000）的合成参数，以优化分子印迹催化剂的组成和结构。更广泛的影响拟议的教育和推广活动旨在激发学生对生物质能和科学与工程基本思想的兴趣。通过路易斯·斯托克斯少数民族参与联盟（AMP）暑期本科生研究项目招募的代表性不足的群体的本科生将有机会参与这项研究。作为推广计划的一部分，PI将与当地一家有线电视台合作，制作有关能源现状和发展可再生能源技术重要性的节目。这个科学节目将在整个费城市区播出。