Sustainable One-Pot Immobilization of Enzymes in/on Metal-Organic Framework Materials

Abstract

The industrial use of enzymes generally necessitates their immobilization onto solid supports. The well-known high affinity of enzymes for metal-organic framework (MOF) materials, together with the great versatility of MOFs in terms of structure, composition, functionalization and synthetic approaches, has led the scientific community to develop very different strategies for the immobilization of enzymes in/on MOFs. This review focuses on one of these strategies, namely, the one-pot enzyme immobilization within sustainable MOFs, which is particularly enticing as the resultant biocomposite Enzyme@MOFs have the potential to be: (i) prepared in situ, that is, in just one step; (ii) may be synthesized under sustainable conditions: with water as the sole solvent at room temperature with moderate pHs, etc.; (iii) are able to retain high enzyme loading; (iv) have negligible protein leaching; and (v) give enzymatic activities approaching that given by the corresponding free enzymes. Moreover, this methodology seems to be near-universal, as success has been achieved with different MOFs, with different enzymes and for different applications. So far, the metal ions forming the MOF materials have been chosen according to their low price, low toxicity and, of course, their possibility for generating MOFs at room temperature in water, in order to close the cycle of economic, environmental and energy sustainability in the synthesis, application and disposal life cycle.

Expression and immobilization of trypsin‐like domain of serine protease from Pseudomonas aeruginosa for improved stability and catalytic activity

“…The immobilized domain showed affinity toward substrate compared to the free domain, which could be due to conformational changes in enzyme that may change the microenvironment of enzyme and result in greater accessibility of substrate to the active site of the enzyme 37 . Similar results of increased affinity of the immobilized enzyme toward substrate have been reported in many studies 38,39 …”

“…37 Similar results of increased affinity of the immobilized enzyme toward substrate have been reported in many studies. 38,39 The kinetic studies indicated a decrease in K m for immobilized trypsin-like domain indicating better substrate affinity. 40 Bornscheuer 41 showed that immobilization modifies the active site of the enzyme thus reducing its K m value.…”

Dual-Modal Nanoscavenger for Detoxification of Organophosphorus Compounds

“…Enzyme immobilization is an effective method to improve the stability of bioscavengers. Specifically, multiple strategies, such as adsorption, covalent bonding, encapsulation, and copolymerization, can be used to physically attach enzymes to a solid support (carrier) to isolate enzymes from aggressive environments. − Mesoporous metal–organic frameworks (MOFs) have emerged as advanced materials for enzyme immobilization due to their tunable size, high surface area, and possible biofunctionalization. − These special properties endow MOFs with high enzyme loading, stable catalytic activity, and excellent diffusion of both substrate and product . Zeolitic imidazole framework-8 (ZIF-8), formed by coordination between 2-methylimidazole and Zn 2+ ions, is a typical and excellent MOF material for one-pot enzyme encapsulation with mild synthesis conditions and good biocompatibility and stability. , However, clearance by the immune system is still one of the major issues of enzyme/MOF nanoparticles, which may lead to attenuation of enzyme activity, necessitating further functionalization of these nanoparticles. , …”

Chemical Modification of Glycoproteins’ Carbohydrate Moiety as a General Strategy for the Synthesis of Efficient Biocatalysts by Biomimetic Mineralization: The Case of Glucose Oxidase

“…There are three general approaches for the preparation of MOF-based enzyme composites: surface attachment, post-synthetic diffusion, and encapsulation [3][4][5][6][7]. Either a surface attachment can be made by physical adsorption, or an enzyme can be grafted onto the MOF's surface (covalent or supramolecular attachment).…”