Understanding and Engineering the Nucleation of Enzyme Metal-Organic Frameworks

酶是天然催化剂，可用于化学工业，以加快反应速度和减少催化过程的能量需求。然而，酶在它们进化的生理环境之外通常是不稳定的，这极大地限制了它们在工业应用中的效用。这个问题的一个潜在解决方案是将酶固定在支撑结构上。理想的支撑材料必须能够装载大量的酶的活性形式。与溶液中的游离酶相比，该载体还应增加酶的稳定性和可回收性。金属有机骨架是一类很有前途的酶固定化材料。mof是由金属离子与有机配体自组装而成的多孔晶体材料。在室温下，只需将金属、配体和酶在水溶液中混合即可将酶固定在mof上。酶在成核和生长过程中被纳入MOF框架。要了解这个过程是如何工作的，需要对系统的成核和生长机制进行详细的分析。这些基本的机制知识将为酶固定化mof的合成提供可靠的设计规则，并具有高负载的酶活性形式。在MOF表面固定几乎任何酶的能力有可能彻底改变生物技术产业，并通过低能量的化学过程造福社会。研究者还将开发一种移动的K-12外展活动，使用低成本显微镜观察盐晶体的生长。本项目旨在确定酶MOF复合材料的成核和生长机制。该方法采用低温和液相电子显微镜。低温电子显微镜将用于捕获中间体并分析其高分辨率结构。液相电子显微镜将用于监测吸收、成核和生长的动力学。电子显微镜数据将由光和x射线的体散射分析来支持。从这些机理研究中获得的知识将用于重新设计界面化学，以提高包封效率和酶活性。该项目将揭示形成机制，如何通过调整界面化学来操纵机制，以及结构-性质关系。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Enzymes are natural catalysts that can be used by chemical industries to speed up the rate of reactions and reduce the energy requirements of catalytic processes. However, enzymes are not typically stable outside of the physiological environment in which they evolved, significantly limiting their utility for industrial applications. A potential solution to this problem is to immobilize enzymes onto support structures. The ideal support material must be capable of loading high quantities of the active form of the enzyme. The support should also increase the stability and recyclability of the enzyme compared to the free enzyme in solution. Metal-organic frameworks (MOFs) are a promising class of materials for enzyme immobilization. MOFs are porous crystalline materials formed by the self-assembly of metal ions and organic ligands. Enzymes can be immobilized on MOFs by simply mixing the metal, ligand, and enzyme in aqueous solutions at room temperature. The enzymes are then incorporated into the MOF framework during the nucleation and growth processes. Understanding how this process works requires a detailed analysis of the system's nucleation and growth mechanisms. This fundamental mechanistic knowledge will provide robust design rules for the synthesis of enzyme-immobilized MOFs with high loading of the active form of the enzyme. The ability to immobilize practically any enzyme at the MOF surface has the potential to revolutionize the biotechnology industry and benefit society through lower energy chemical processes. The investigator will also develop a mobile K-12 outreach activity that uses low-cost microscopy to observe salt crystal growth. This project aims to determine the nucleation and growth mechanisms of enzyme MOF composite materials. The approach employs cryogenic and liquid-phase electron microscopy. Cryogenic electron microscopy will be used to trap intermediates and analyze their high-resolution structure. Liquid-phase electron microscopy will be used to monitor the kinetics of absorption, nucleation, and growth. The electron microscopy data will be supported by bulk scattering analysis using light and X-rays. The knowledge gained from these mechanistic studies will be used to re-engineer the interfacial chemistry to improve both encapsulation efficiency and enzymatic activity. The project will reveal the formation mechanisms, how the mechanisms can be manipulated by tuning the interfacial chemistry, and the structure-property relationships.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.