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.

该提案的总体目标是设计和研究新的活性柔性和半柔性聚合物纳米载体平台，其将使多种活性酶能够纳米级空间共定位。自然界中发现的几种多酶复合物被设计用于确保反应中的每个中间体快速转运到下一个相邻的活性位点，因为中间体通常不稳定。因此，将这些酶分子共定位在纳米载体中是至关重要的，这样活性中间体就可以找到下一个活性位点来形成所需的产物。虽然已经有许多研究涉及酶的固定化，但还没有研究使用纳米材料来共定位多酶复合物，特别是与活性中间体。因此，该提案的重点是创建活性纳米结构环境，该环境可以通过在空间和时间尺度内限制活性催化功能来修改复杂转化的方向。我们将研究黄烷-3-醇的生物合成，其生产是由两种酶介导的高活性中间体。黄烷-3-醇，如（-）表儿茶素，是具有强大抗氧化特性的类黄酮天然产物，并且是各种食物如绿色茶和黑巧克力的心脏保护和抗癌活性的主要贡献者。该项目的具体目标是：1）设计和表征基于自组装离子和可降解共聚物的新型纳米载体平台，以与活性中间体共定位和稳定多种酶; 2）研究用于黄酮-3-醇生物合成的纳米载体中的酶活性和通量。一个多元化和跨学科的研究团队已经组装来解决这个问题。智力优点：新的生物启发的强大的活性纳米载体平台与定制的化学将被设计成使纳米级的时空控制的多种酶。这些材料形成各种稳定的纳米隔室/纳米结构。选择这些平台来研究纳米结构的灵活性如何影响酶的共定位和催化活性。这种限制也预期增加相对脆弱的酶生物催化剂的稳定性。将使用实验纳米级工具和计算方法研究纳米隔室与酶的结构，动力学，运输特性和热力学相互作用，以深入了解活性机制。这种方法将有助于合理设计的活性纳米载体平台。这些见解将用于研究纳米封装对黄烷-3-醇生物合成中的多酶复合物的酶活性和产物通量的影响。更广泛的影响：纳米载体平台可以扩展到有效地介导许多其他重要的多酶反应与活性中间体（例如，三羧酸循环）并将反应导向所需的产物，否则这些产物是不可能的。由环境响应性纳米载体平台提供的酶稳定和改善的通量的双重功能将为酶促生物催化剂在级联反应中的工业应用提供一般策略，包括它们在名义上苛刻的条件下的有效（再）使用。开发的纳米探针，以阐明基本的纳米结构功能关系，可以很容易地应用到其他材料/生物分子系统。该提案整合了研究和教育举措，为学生提供多方面和跨学科的学习体验。一个多元化的学生群体将被积极招募。这项工作将通过传播解决问题的标准和生物伦理学案例研究，在全国范围内产生影响。该提案将通过研究经验和几个推广机制影响K-12学生。该项目的结果将通过专业会议、研讨会和档案出版物上的酶纳米催化会议广泛传播。