Artificial Peroxidase/Oxidase Multiple Enzyme System Based on Supramolecular Hydrogel and Its Application as a Biocatalyst for Cascade Reactions

Abstract

Inspired by delicate structures and multiple functions of natural multiple enzyme architectures such as peroxisomes, we constructed an artificial multiple enzyme system by coencapsulation of glucose oxidases (GOx) and artificial peroxidases in a supramolecular hydrogel. The artificial peroxidase was a functional complex micelle, which was prepared by the self-assembly of diblock copolymer and hemin. Compared with catalase or horseradish peroxidase (HRP), the functional micelle exhibited comparable activity and better stability, which provided more advantages in constructing a multienzyme with a proper oxidase. The hydrogel containing the two catalytic centers was further used as a catalyst for green oxidation of glucose, which was a typical cascade reaction. Glucose was oxidized by oxygen (O2) via the GOx-mediated reaction, producing toxic intermediate hydrogen peroxide (H2O2). The produced H2O2 further oxidized peroxidase substrates catalyzed by hemin-micelles. By regulating the diffusion modes of the enzymes and substrates, the artificial multienzyme based on hydrogel could successfully activate the cascade reaction, which the soluble enzyme mixture could not achieve. The hydrogel, just like a protective covering, protected oxidases and micelles from inactivation via toxic intermediates and environmental changes. The artificial multienzyme could efficiently achieve the oxidation task along with effectively eliminating the toxic intermediates. In this way, this system possesses great potentials for glucose detection and green oxidation of a series of substrates related to biological processes.

A facile preparation method for new two-component supramolecular hydrogels and their performances in adsorption, catalysis, and stimuli-response

“…23 Qu et al constructed a peroxidase/oxidase enzyme system based on a supramolecular hydrogel and investigated its application on cascade reactions as a biocatalyst. 24 Potier et al showed that the addition of methylated b-cyclodextrin in the supramolecular hydrogel could exert a positive effect on the catalytic activity of the hydroformylation reaction. 25 Guan et al reported the formation of a novel hydrogel via a host-guest complexation between PNIPAM and a cyclodextrin dimer, and the hydrogel responded sensitively to temperature, light, and reduction stimuli, in the form of a sol-gel conversion.…”

Self-Morphing, Chemically Driven Gears and Machines

“…The value of K M for this reaction is 0.093 M. 27,28 The solutal expansion coefficient for oxygen (0.0014 M À1 ) 29 is an order of magnitude smaller than that for H 2 O 2 (0.011 M À1 ). Consequently, we neglect the contribution of O 2 to solutal buoyancy force in our calculations.…”

Synthesis, Catalytic Properties and Application in Biosensorics of Nanozymes and Electronanocatalysts: A Review

“…Since then, the number of such materials has been growing constantly. These include different material types, such as Nafion-cytochrome c [ 85 ], supramolecular complexes of hydrogel [ 86 ], nanocomplexes of lanthanides [ 87 , 88 , 89 , 90 , 91 , 92 ], Co 3 O 4 @CeO 2 hybrid microspheres [ 93 ], transition metal oxides and their composites [ 71 , 94 , 95 , 96 , 97 , 98 , 99 ], as well as noble metals: Au [ 100 ], Fe/Au [ 101 ], Au/Pt [ 102 ], Pt [ 103 , 104 ], Ru [ 105 ], Pt/Ru [ 60 ], Pd, Pd@Pt [ 106 ], Pd/Pt [ 107 ], Pd@γ-Fe 2 O 3 [ 108 ], etc. In the last decade, special interest in bionanotechnology has focused on the use of NZs based on carbon materials such as fullerenes [ 109 ], Prussian blue [ 110 ], TiO 2 [ 111 ] or Fe 2 O 3 /Pt-modified [ 112 ] multi-walled carbon nanotubes, hemin-graphene hybrid nanosheets [ 113 ], Pt/Ru/3D graphene foam [ 114 ], graphene oxide [ 115 ], Au/Pt/Au-graphene oxide nanosheets [ 116 ], Pd-magnetic graphene nanosheets [ 117 ], hemin-graphene-Au hybrid [ 118 ], IrO 2 [ 119 ], Cu-Ag [ 120 ] or Fe 2 O 3 -modified graphene oxide [ 121 ] ( Figure 4 ), Co-modified magnetic carbon [ 122 ], Co 3 O 4 graphene composite [ ...…”