Molecular Design of Nano-Carrier Materials for Reactions Catalyzed by Multi-Enzyme Complexes

多酶复合物催化反应纳米载体材料的分子设计

• 批准号: 0932517
• 负责人: Surya Mallapragada
• 金额: $ 33万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0932517&HistoricalAwards=false
• 关键词: Molecular; Design; Nano; Carrier; Materials

0932517MallapragadaThe overall objective of this proposal is to design and investigate novel active flexible and semi flexible polymeric nano-carrier platforms that will enable nanoscale spatial co-localization of multiple active enzymes. Several multi-enzyme complexes found in Nature are designed to ensure rapid transport of each intermediate in the reaction to the next neighboring active site, since the intermediates are often unstable. Thus, it is critical to molecularly co-localize these enzymes in nano-carriers so that the reactive intermediates can find the next active site for the desired products to be formed. While there have been numerous studies dealing with enzyme immobilization, there are no studies of using nanomaterials to co-localize multi-enzyme complexes, especially with reactive intermediates. Thus, the focus of this proposal is to create active nanostructured environments that can modify the direction of complex conversions by confinement of the active catalytic functionality within both spatial and temporal scales. We will investigate the biosynthesis of flavan-3-ol, whose production is mediated by two enzymes with a highly reactive intermediate. Flavan-3-ols, such as (-) epicatechin, are flavonoid natural products with powerful antioxidant properties and are the major contributors to the cardioprotective and anticancer activity of various foods such as green tea and dark chocolate. The specific goals of the project are to: 1) Design and characterize novel nano carrier platforms based on self-assembling ionic and degradable copolymers to co-localize and stabilize multiple enzymes with reactive intermediates; and 2) Investigate enzymatic activity and flux in nano-carriers for flavon-3-ol biosynthesis. A diverse and interdisciplinary team of researchers has been assembled to address this problem.Intellectual Merit: New bioinspired robust active nano carrier platforms with tailored chemistries will be designed to enable nanoscale spatio-temporal control of multiple enzymes. These materials form various stable nano-compartments/nanostructures. These platforms have been chosen to investigate how the flexibility of the nanostructure affects the co-localization and catalytic activity of the enzymes. This confinement is also expected to increase the stability of relatively delicate enzymatic biocatalysts. The structure, dynamics, transport properties, and thermodynamic interactions of the nano-compartments with enzymes will be investigated using experimental nanoscale tools and computational methods to obtain insights into the mechanisms of activity. This approach will facilitate rational design of the active nano-carrier platforms. These insights will be used to investigate the effects of nano-encapsulation on the enzymatic activity of, and product flux through, a multi enzyme complex in flavan-3-ol biosynthesis.Broader Impact: The nano carrier platforms can be extended to effectively mediate many other important multi enzyme reactions with reactive intermediates (e.g., the tricarboxylic acid cycle) and channel reactions towards desired products that might not otherwise be possible. The dual functions of enzyme stabilization and improved flux provided by the environmentally responsive nano-carrier platforms will provide a general strategy for industrial use of enzymatic biocatalysts in cascade reactions, including their efficient (re)use under nominally harsh conditions. The nanoscale probes developed to elucidate fundamental nanostructure function relationships can be readily applied to other material/biomolecule systems. This proposal integrates research and educational initiatives to provide students multifaceted and interdisciplinary learning experiences. A diverse group of students will be proactively recruited. This work will have a nation-wide impact through the dissemination of problem-solving rubrics and bioethics case studies. This proposal will impact K-12 students through research experiences and several outreach mechanisms. Results from the project will be disseminated broadly through sessions on enzyme nanocatalysis at professional meetings, workshops, and archival publications.

该建议的0932517-Mallapragadathe的总体目标是设计和研究新型的活动柔性和半柔性聚合物纳米载体平台，该平台将使纳米级空间共定位多种活性酶。由于中间体通常不稳定，因此在自然界中发现的几种多酶复合物旨在确保每个中间体在反应中的每个中间体快速运输。因此，将这些酶共定位在纳米载体中至关重要，以便反应性中间体可以找到形成所需产品的下一个活性位点。虽然有许多研究酶固定化的研究，但尚无研究使用纳米材料共定位的多酶复合物，尤其是与反应性中间体一起进行的。因此，该建议的重点是创建活跃的纳米结构环境，可以通过在空间和时间尺度内限制主动催化功能来修改复杂转换的方向。我们将研究Flavan-3-OL的生物合成，其生产是由具有高反应性中间体的两种酶介导的。 Flavan-3-ols，例如（ - ）epicatechin是具有强大抗氧化特性的类黄酮天然产品，是各种食物（例如绿茶和黑巧克力）的心脏保护和抗癌活性的主要因素。该项目的具体目标是：1）设计和表征基于自组装和可降解共聚物的新型纳米载体平台，以共同定位并稳定与反应性中间体的多种酶； 2）研究Flavon-3-ol生物合成的纳米载体中的酶活性和通量。一支多样化和跨学科的研究人员团队已组装以解决这个问题。智能优点：具有量身定制的化学作用的新生物启发的活跃纳米载体平台将旨在实现多种酶的纳米级时空控制。这些材料构成了各种稳定的纳米组件/纳米结构。选择这些平台是为了研究纳米结构的灵活性如何影响酶的共定位和催化活性。预计这种限制也将增加相对细腻的酶生物催化剂的稳定性。将使用实验性纳米级工具和计算方法研究纳米组合与酶的结构，动力学，传输特性和热力学相互作用，以获取有关活动机制的见解。这种方法将促进主动纳米载体平台的合理设计。这些见解将用于研究纳米封装对Flavan-3-ol Biosynsess中多酶复合物的酶活性和产品通量的影响。Boader的影响：纳米载体平台可以扩展以有效地介导许多介导许多酶。其他重要的多酶反应与反应性中间体（例如三羧酸周期）和对所需产品的通道反应，这些反应可能是不可能的。酶稳定的双重功能和改善环境响应的纳米载体平台提供的通量，将为级联反应中酶促生物催化剂的工业使用提供一般策略，包括其在名义恶劣条件下的有效（RE）使用。为阐明基本纳米结构功能关系而开发的纳米级探针可以很容易地应用于其他材料/生物分子系统。该建议将研究和教育计划整合在一起，以为学生提供多方面和跨学科的学习经验。一群不同的学生将被积极招募。这项工作将通过传播解决问题的专栏和生物伦理学案例研究而在全国范围内产生影响。该建议将通过研究经验和几种外展机制影响K-12学生。该项目的结果将通过专业会议，讲习班和档案出版物的酶纳米催化会议大致传播。