氧化铁磁性纳米粒子固定化酶*

纳米粒子作为酶固定化的载体,当其具有磁性时,制备的固定化酶易于从反应体系中分离和回收,操作简便;并且利用外部磁场可以控制磁性材料固定化酶的运动方式和方向,替代传统的机械搅拌方式,提高固定化酶的催化效率。在众多纳米材料中,氧化铁因其在磁性、催化等多方面的良好特性而倍受瞩目。本文对近年来各种氧化铁磁性纳米粒子固定化酶,尤其是固定化脂肪酶和蛋白酶的制备方法及其应用做了较为详细的阐述,对这些氧化铁磁性纳米粒子固定化酶的优缺点和发展前景进行了讨论。     

碳酸酐酶固定化研究进展

近年来,碳酸酐酶(CA)在CO_2捕集领域的应用引起人们极大的兴趣.然而,由于价格昂贵,游离酶在使用时活性易受到多种环境因素的影响,稳定性较低且不易回收,因此有必要对CA固定化.综述了近十多年来CA固定化的研究进展,并根据载体的种类进行划分,分别总结了高分子材料、无机材料、聚合物-无机复合材料、纳米材料固定化CA的酶来源、固定化方法、载体材料、酶活、反应动力学参数和稳定性数据,并介绍了固定化CA应用于反应器的研究进展.最后,指出了不同类型载体材料的优缺点,提出了固定化CA的未来发展方向.     

石墨烯固定化酶研究进展

固定化酶具有高效催化、可重复利用及易分离等优点,在食品、医药等工业生产领域及微观生化检测领域具有广泛应用。固定化酶的性能与载体材料关系密切。石墨烯作为一种广受关注的纳米材料,其独特而优良的物化性能是固定酶的理想载体。本文主要介绍了近年来以石墨烯及其衍生物为载体的固定化酶技术的发展状况。重点对以物理吸附法、化学键合法和包埋法为主的各种石墨烯固定化酶的制作方法,以及其在酶微反应器和生物传感等领域的最新应用进行详细的评述,并对其今后的发展前景进行了展望。     

蛋白质组学中的固定化酶反应器制备的研究进展

固定化酶反应器作为蛋白质组学研究中"bottom-up"策略重要的组件,具有酶解快速、酶解效率高、酶稳定性和活性高、简单易操作、能够与多种检测方式联用等优点,对于发展高效快速的蛋白质组学分析方法具有重要意义。本文就固定化酶反应器的制备方法及其在蛋白质组学中的应用做简单的概述,着重介绍酶的固定方法、固定化酶的载体、用于固定的酶的种类。近几年固定化酶反应器的研究集中于提高固酶量、保持酶活性、增加酶解效率、减小非特异性吸附等方面。研究结果表明,采用纳米材料、整体材料等新型载体,提高载体亲水性,采用多酶同时酶解等方法能够有效改善固定化酶反应器的性能,提高蛋白质的鉴定效率。     

静电纺丝纳米纤维膜固定化酶及其应用*

静电纺丝是一种简单有效的制备聚合物纳米纤维的技术,在组织工程、药物控释和传感器等方面具有广泛的应用。采用静电纺丝技术制备得到的纳米纤维膜具有比表面积大、孔隙率高和易于分离回收等优点,可以作为一种优良的酶固定化载体,目前在酶固定化领域受到了广泛的关注。本文综述了近年来静电纺丝纳米纤维膜固定化酶的研究进展,在阐述静电纺丝纳米纤维膜制备技术的基础上,详细介绍了纳米纤维膜表面担载法和包埋法固定化酶的原理和方法,分析了不同固定化方法的优缺点,并讨论了静电纺丝纳米纤维膜固定化酶的应用前景,对静电纺丝纳米纤维膜固定化酶的发展方向进行了展望。     

固定化酶反应器及其在蛋白质组研究中的应用

综述了近年来国内外酶固定化载体的研究进展,侧重于无机材料和有机聚合物材料上的固定化酶方法;此外,也介绍了固定化胰蛋白酶反应器与分离系统联用在蛋白质样品分析中的应用,并展望了固定化酶反应器的研究方向及其在蛋白质组中的应用前景。     

共价有机框架材料固定化酶的研究进展

共价有机框架（Covalent Organic Frameworks, COFs）是一种新型的多孔材料,具有结构规整、骨架稳定、孔径结构可调等特点,被视为固定化酶的理想载体。我们主要总结了近10年来COFs材料作为载体,通过物理吸附、共价连接、包埋的固定化策略制备固定化酶的研究进展与应用,并讨论了COFs材料在酶固定化领域所面临的机遇和挑战。     

共价有机框架材料在固定化酶及模拟酶领域的应用

共价有机框架(Covalent Organic Frameworks, COFs)是一类由轻质元素通过可逆共价键连接而成的晶型多孔有机材料。因具有高比表面积、低密度、规则的孔隙和易于功能化等独特的性能和结构,COFs在气体吸附、化学传感和非均相催化等领域有着广泛的应用前景。近年来,COFs逐渐显现出在固定化酶和模拟酶领域的应用潜力,由于可以轻松定制COF上的官能团以保持COF与酶之间的特定相互作用,因此COF成为有吸引力的酶固定基质。此外,COF的连续且封闭的开放通道为渗透酶提供了良好的微环境。同时,探索了COF模拟酶的特征,通过“从下到上”的方法或后修饰策略设计了COF模拟酶。这不仅扩展了固定化酶载体材料的研究和应用范围,还为模拟酶仿生催化提供了新的研究思路。本文综述了COFs固定化酶和作为纳米材料模拟酶(纳米酶)在生物催化领域的研究进展,详细讨论了COFs载体的合成和功能化策略、固定化酶方式,以及COFs纳米酶的设计理念、催化活性和选择性等内容。最后总结了目前COFs在酶催化领域所面临的挑战和未来发展的机遇。     

酶固定化技术用载体材料的研究进展

酶的固定化是生物技术中最为活跃的研究领域之一.作为固定化酶技术的重要组成部分,载体的结构及性能在很大程度上直接影响着所得固定化酶的催化活性及操作稳定性.综合性能优良的载体材料的设计与制备是固定化酶技术领域的一个非常重要的研究内容.通过对传统材料的改性和新型载体材料的研究开发,必将促进固定化酶在各个领域的广泛应用.本文综述了近年来国内外有关固定化酶载体材料的研究现状和发展趋势.     

GOx@GA@MIL-101金属有机骨架用于葡萄糖的快速比色识别

金属有机骨架(MOFs)材料具有均匀的孔隙率和大的比表面积,可作为固定化酶的载体。然而,固定化酶由于较长响应时间或酶易泄漏的缺点阻碍了其应用。本研究选取类过氧化物酶MIL-101为载体,戊二醛(GA)为交联剂,通过交联法将葡萄糖氧化酶(GOx)固定在载体上,建立了模拟多酶体系GOx@GA@MIL-101。制备的复合物可进一步高效催化级联反应检测葡萄糖。GOx@GA@MIL-101具有更快的催化变色效果(30 s)。     

High-performance cascade nanoreactor based on halloysite nanotubes-integrated enzyme-nanozyme microsystem

Various enzymatic reactions or enzymatic cascade reactions occur efficiently in biological microsystems due to space constraints or orderly transfer of intermediate products. Inspired by this, the horseradish peroxidase(HRP)-like nanozyme(Fe-aminoclay) was in situ synthesized on the surface of alkali-activated halloysite nanotubes and the natural enzyme(glucose oxidase, GOx) was immobilized on it to construct a high-efficiency GOx-Fe AC@AHNTs cascade nanoreactor. In which, Fe AC@AHNTs can not on...     

Enzyme immobilization strategies for the design of robust and efficient biocatalysts

Different strategies for the preparation of efficient and robust immobilized biocatalysts are here reviewed. Different physico-chemical approaches are discussed.i.- The stabilization of enzyme by any kind of immobilization on pre-existing porous supports.ii.- The stabilization of enzymes by multipoint covalent attachment on support surfaces.iii.- Additional stabilization of immobilized-stabilized enzyme by physical or chemical modification with polymers.These three strategies can be easily developed when enzymes are immobilized in pre-existing porous supports. In addition to that, these immobilized-stabilized derivatives are optimal to develop enzyme reaction engineering and reactor engineering. Stabilizations ranging between 1000 and 100,000 folds regarding diluted soluble enzymes are here reported.     

GOx@GA@MIL-101金属有机骨架用于葡萄糖的快速比色识别

金属有机骨架(MOFs)材料具有均匀的孔隙率和大的比表面积,可作为固定化酶的载体。然而,固定化酶由于较长响应时间或酶易泄漏的缺点阻碍了其应用。本研究选取类过氧化物酶 MIL-101为载体,戊二醛(GA)为交联剂,通过交联法将葡萄糖氧化酶(GOx)固定在载体上,建立了模拟多酶体系GOx@GA@MIL-101。制备的复合物可进一步高效催化级联反应检测葡萄糖。GOx@GA@MIL-101具有更快的催化变色效果(30 s)。     

Nanoengineered ligninolytic enzymes for sustainable lignocellulose biorefinery

Lignin is a key structural component of lignocellulosic biomass with immense potential to replace non-renewable and environmentally unfriendly fossil resources. Structural recalcitrance, heterogeneity, and multifaceted composition of lignin are the major impediments to its gainful biotransformation to a spectrum of bio-based products, biomaterials, and specialty chemicals. In contrast to physicochemical methods, harnessing the biocatalytic potential of the robust ligninolytic armory is considered a greener and more sustainable way for lignin biorefinery. Immobilization of ligninolytic enzymes on different nanoengineered support matrices resulted in designing nanobiocatalytic system with intensified catalytic performance and long-term stability for efficient lignocellulosic biomass valorization. Enzyme incorporation on magnetic nanostructures additionally facilitates facile separation, recovery, and reusability of magnetic nanobiocatalysts. Therefore, developing and implementing immobilized ligninolytic enzyme-based nanoengineered biocatalytic systems constitutes a prodigious and eco-sustainable option to catalyze the deconstruction of lignocellulosic biomass. The multi-enzyme nano-biocatalytic system offers the advantage of direct substrate conversion into the product in a single step owing to its concurrent biocatalytic attributes. This opinion article spotlights current achievements and state-of-the-art developments in engineering ligninolytic enzymes to create a novel biocatalytic system to create greener and sustainable lignocellulose biorefineries ranging from the production of biomaterials to bioenergy.     

Bioinorganic Nanocomposite Hydrogels Formed by HRP–GOx‐Cascade‐Catalyzed Polymerization and Exfoliation of the Layered Composites

The mild preparation of multifunctional nanocomposite hydrogels is of great importance for practical applications. We report that bioinorganic nanocomposite hydrogels, with calcium niobate nanosheets as cross‐linkers, can be prepared by dual‐enzyme‐triggered polymerization and exfoliation of the layered composite. The layered HRP/calcium niobate composites (HRP=horseradish peroxidase) are formed by the assembly of the calcium niobate nanosheets with HRP. The dual‐enzyme‐triggered polymerization can induce the subsequent exfoliation of the layered composite and final gelation through the interaction between polymer chains and inorganic nanosheets. The self‐immobilized HRP‐GOx enzymes (GOx=glucose oxidase) within the nanocomposite hydrogel retain most of enzymatic activity. Evidently, their thermal stability and reusability can be improved. Notably, our strategy could be easily extended to other inorganic layered materials for the fabrication of other functional nanocomposite hydrogels.     

Monolith-based immobilized enzyme reactors: recent developments and applications for proteome analysis

In the current proteome study, protein digestion is indispensable before proteins could be identified by MS/MS, no matter based on top-down or bottom-up strategies. Compared to the traditional digestion performed in free solution, immobilized enzyme shows great advantages in digestion speed, stability, and longevity, especially with monolithic materials as the supports. Besides the improved digestion capacity, the immobilized enzyme reactors (IMERs) could be further coupled with the separation and detection systems, enabling high-throughput protein identification. In this paper, the latest advances in the monolith-based IMERs and their applications in proteomic study are briefly summarized. By reviewing these achievements, it could be seen that monilith-based IMERs have very bright future in proteome analysis.     

Construction of coacervate-in-coacervate multi-compartment protocells for spatial organization of enzymatic reactions

Coacervate microdroplets, formed via liquid–liquid phase separation, have been extensively explored as a compartment model for the construction of artificial cells or organelles. In this study, coacervate-in-coacervate multi-compartment protocells were constructed using four polyelectrolytes, in which carboxymethyl-dextran and diethylaminoethyl-dextran were deposited on the surface of as-prepared polydiallyldimethyl ammonium/deoxyribonucleic acid coacervate microdroplets through layer-by-layer assembly. The resulting multi-compartment protocells were composed from two immiscible coacervate phases with distinct physical and chemical properties. Molecule transport experiments indicated that small molecules could diffuse between two coacervate phases and that macromolecular enzymes could be retained. Furthermore, a competitive cascade enzymatic reaction of glucose oxidase/horseradish peroxidase–catalase was performed in the multi-compartment protocells. The different enzyme organization and productions of H₂O₂ led to a distinct polymerization of dopamine. The spatial organization of different enzymes in immiscible coacervate phases, the distinct reaction fluxes between coacervate phases, and the enzymatic cascade network led to distinguishable signal generation and product outputs. The development of this multi-compartment structure could pave the way toward the spatial organization of multi-enzyme cascades and provide new ideas for the design of organelle-containing artificial cells.

A coacervate-in-coacervate micro-architecture is constructed as a multi-compartment protocell model, in which a multi-enzyme cascade is spatially organized for competitive enzymatic reactions.     

Enzymes immobilized in mesoporous silica: A physical–chemical perspective

Mesoporous materials as support for immobilized enzymes have been explored extensively during the last two decades, primarily not only for biocatalysis applications, but also for biosensing, biofuels and enzyme-controlled drug delivery. The activity of the immobilized enzymes inside the pores is often different compared to that of the free enzymes, and an important challenge is to understand how the immobilization affects the enzymes in order to design immobilization conditions that lead to optimal enzyme activity. This review summarizes methods that can be used to understand how material properties can be linked to changes in enzyme activity. Real-time monitoring of the immobilization process and techniques that demonstrate that the enzymes are located inside the pores is discussed by contrasting them to the common practice of indirectly measuring the depletion of the protein concentration or enzyme activity in the surrounding bulk phase. We propose that pore filling (pore volume fraction occupied by proteins) is the best standard for comparing the amount of immobilized enzymes at the molecular level, and present equations to calculate pore filling from the more commonly reported immobilized mass. Methods to detect changes in enzyme structure upon immobilization and to study the microenvironment inside the pores are discussed in detail. Combining the knowledge generated from these methodologies should aid in rationally designing biocatalyst based on enzymes immobilized in mesoporous materials.     

Biomolecular Release from Alginate‐modified Electrode Triggered by Chemical Inputs Processed through a Biocatalytic Cascade – Integration of Biomolecular Computing and Actuation

Biocatalytic cascades involving more than one or two enzyme‐catalyzed step are inefficient inside alginate hydrogel prepared on an electrode surface. The problem originates from slow diffusion of intermediate products through the hydrogel from one enzyme to another. However, enzyme activity can be improved by surface immobilization. We demonstrate that a complex cascade of four consecutive biocatalytic reactions can be designed, with the enzymes immobilized in an LBL‐assembled polymeric layer at the alginate‐modified electrode surface. The product, hydrogen peroxide, then induces dissolution of iron‐cross‐linked alginate, which results in release process of entrapped biomolecular species, here fluorescently marked oligonucleotides, denoted F‐DNA. The enzymatic cascade can be viewed as a biocomputing network of concatenated AND gates, activated by combinations of four chemical input signals, which trigger the release of F‐DNA. The reactions, and diffusion/release processes were investigated by means of theoretical modeling. A bottleneck reaction step associated with one of the enzymes was observed. The developed system provides a model for biochemical actuation triggered by a biocomputing network of reactions.