微囊型纳米颗粒组装体固定化多酶系统的仿生构建及性能研究

Multienzyme catalysis is considered to be the next generation of biocatalysis. Construction of highly reactive, mechanically stable and easily recyclable multienzyme systems seems to be one of the hot and difficult issues in this area. Therefore, a project entitled "Bio-inspired construction of multienzyme systems upon capsular nanoparticle assembly and performance investigation" is proposed. The main content includes the following aspects: 1) synthesize active silica nanoparticles with different sizes through incorporating catechol chemistry into biomimetic silicification process, and then investigate the formation and regulation mechanisms; 2) fabricate multienzyme-immobilized nanoparticles, testify the catalytic activity and then clarify the relationship among particle structure, enzyme microenvironment and enzyme catalytic activity. Notably, two enzymes are, respectively, in situ entrapped in the inner core and chemically conjugated on the surface of the nanoparticles; 3) construct spatially separated multienzyme catalytic systems upon capsular nanoparticle assembly, and then investigate the microenvironment-regulation and performance-intensification mechanisms. Besides, the constructed multienzyme systems comprising glucose oxidase (GOD) and catalase (CAT) are then utilized for catalytic removing glucose from oligosaccharides (IMO 500). Hopefully, the achievement from our project could offer theoretical basis and technical support for the rational design and construction of multienzyme systems as well as the industrial application of multienzyme catalysis. Furthermore, this project could also provide methodological guidance for the design and synthesis of other hierarchically structured catalysts.

多酶催化被认为是下一代生物催化技术，而构建高活性、强稳定、易回收多酶系统一直是该领域的研究热点和难点。为此，本项目提出“微囊型纳米颗粒组装体固定化多酶系统的仿生构建及性能研究”的思路。主要研究内容包括：1）将儿茶酚化学引入仿生硅化过程，制备不同尺寸的活性氧化硅纳米颗粒，研究其合成及调控机制；2）将两种酶分别采用原位包埋法和共轭接枝法固定于活性氧化硅纳米颗粒内核及表面，获得纳米颗粒固定化多酶，考察其催化性能，揭示颗粒结构-酶微环境-酶催化性能间的内在关系；3）基于纳米颗粒固定化多酶，构建微囊型多酶系统，研究其微环境调控机制及性能强化机制。此外，本项目还将所构建的含葡萄糖氧化酶和过氧化氢酶的多酶系统，尝试性的应用于商品低聚异麦芽糖中葡萄糖的催化去除过程。期望通过本项目的开展为多酶系统的理性构建及多酶催化工业应用提供理论基础和技术支持，同时为其他多尺度结构催化剂的设计制备提供方法指导。

多酶催化介于单酶催化和细胞催化之间，被认为是下一代生物催化技术。 基于仿生思想构建多酶催化系统是生物催化领域的研究热点和难点。受细胞结构和功能启发，本研究制备了系列仿细胞微囊结构，构建了多种含单酶和多酶的生物催化系统，实现了葡萄糖级联转化等过程的高效强化。主要研究内容如下：1）基于仿生矿化、多酚化学等仿生方法制备了系列微囊结构，考察了制备条件等对微囊结构（囊壁厚度等）等的影响规律，阐释了微囊结构的形成和调控机制。2）基于微囊结构构建了单酶和多酶催化系统，固载了葡萄糖氧化酶、过氧化物酶等单酶及葡萄糖氧化酶-过氧化物（氢）酶等多酶，考察了微囊结构对酶催化性能的影响规律，阐释了二者间内在关系，实现了单酶和多酶催化过程性能强化。3）基于微囊型单酶和多酶催化系统，构建了整体生物微反应器，实现了葡萄糖的连续高效转化。本研究成果在血糖检测、低聚糖提纯等领域中具有一定应用前景，同时也适用于其他单酶和多酶催化过程。因此，本研究可为生物催化系统，尤其是多酶催化系统，的构建及应用提供理论指导和技术支撑。