Conjugation of enzyme on superparamagnetic nanogels covered with carboxyl groups

Jiang, Hong; Xu, Dongdong; Gong, Peijun; Ma, Hongjuan; Dong, Li; Yao, Side

doi:10.1016/j.jchromb.2006.12.035

Cited by 35 publications

(25 citation statements)

References 28 publications

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“…For instance, coupling reactions can be performed using reactive groups such as amines, carboxylates and thiols. Carboxylic groups can be activated with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, or EDC (Kondo and Fukuda 1997) in order to bind amines, yielding stable amide bonds linking the enzyme to the support (Bílková et al 2002, Hong et al 2007, Demirel et al 2004, Demirel and Mutlu 2005, Zeng et al 2006, Guo et al 2003, Iman et al 1992, Pan et al 2009). Amine groups can be linked by means of glutaraldehyde, forming imine bonds, which can further be reduced with NaBH 4 .…”

Section: Enzyme Immobilizationmentioning

confidence: 99%

Carbon dioxide/methanol conversion cycle based on cascade enzymatic reactions supported on superparamagnetic nanoparticles

Netto

Andrade

Toma

2017

An. Acad. Bras. Ciênc.

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The conversion of carbon dioxide into important industrial feedstock is a subject of growing interest in modern society. A possible way to achieve this goal is by carrying out the CO 2 /methanol cascade reaction, allowing the recycle of CO 2 using either chemical catalysts or enzymes. Efficient and selective reactions can be performed by enzymes; however, due to their low stability, immobilization protocols are required to improve their performance. The cascade reaction to reduce carbon dioxide into methanol has been explored by the authors, using, sequentially, alcohol dehydrogenase (ADH), formaldehyde dehydrogenase (FalDH), and formate dehydrogenase (FDH), powered by NAD + /NADH and glutamate dehydrogenase (GDH) as the co-enzyme regenerating system. All the enzymes have been immobilized on functionalized magnetite nanoparticles, and their reactions investigated separately in order to establish the best performance conditions. Although the stepwise scheme led to only 2.3% yield of methanol per NADH; in a batch system under CO 2 pressure, the combination of the four immobilized enzymes increased the methanol yield by 64 fold. The studies indicated a successful regeneration of NADH in situ, envisaging a real possibility of using immobilized enzymes to perform the cascade CO 2 -methanol reaction.

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Section: Enzyme Immobilizationmentioning

confidence: 99%

Carbon dioxide/methanol conversion cycle based on cascade enzymatic reactions supported on superparamagnetic nanoparticles

Netto

Andrade

Toma

2017

An. Acad. Bras. Ciênc.

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“…The residual lipase solution was used to determine the content of the immobilized lipase, as the difference of lipase concentration in the initial and the residual solution, together with the lipase concentration of the sample washing steps. The amount of CRL immobilized into hydrogels was determined by measuring the enzyme concentration in the washing solution, using BCA protein assay [21], and the binding capacity was calculated using following equation:…”

Section: Hydrogel Synthesismentioning

confidence: 99%

Efficient immobilization of lipase from Candida rugosa by entrapment into poly(N-isopropylacrylamide-co-itaconic acid) hydrogels under mild conditions

et al. 2012

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Temperature and pH-sensitive hydrogels, based on N-isopropylacrylamide and itaconic acid, with varying comonomer ratios and crosslinking agent content, were prepared by free radical crosslinking copolymerization. The immobilization of lipase from Candida rugosa was carried out by post-loading entrapment method at different temperatures until equilibrium swelling was achieved. The effects of the hydrogel composition and the immobilization temperature on the hydrogel-binding capacity, immobilized lipase specific activity, as well as the enzyme leakage were studied. It was found that the NiPAAm/IA ratio, crosslinking agent concentration and the temperature at which the entrapment was performed significantly affected the hydrogel-binding capacity. The biocatalysts obtained by entrapment into hydrogel with the highest itaconic acid content at 5°C exhibited both highest binding capacity and the highest specific activity, but appeared to be less suitable for repeated uses than those obtained at 25°C.

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“…covering enzymes by a thin polymeric layer (Figure 1: Structure). It has been proved that single enzyme nanocapsules, using organic/inorganic hybrid layer [10,12,13,14] organic acrylic copolymer [11,15], hyperhranched polymer layer [18] or superparamagnetic layer [19,20], can essentially stabilize enzymes. 58(Sup), pp.…”

Section: Introductionmentioning

confidence: 99%

Single Haemoglobin Nanocapsules as Test Materials for Artificial Blood

Hegedüs¹,

Dojcsak²,

Szalai³

et al. 2014

Period. Polytech. Chem. Eng.

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Single protein nanocapsules (SPNs) Keywords single haemoglobin nanocapsules · artificial blood · biocompatibility · allergic reaction IntroductionProteins usually catalyze biological reactions and have enzymatic function. Enzymes are bioreactors with high specificity and selectivity. But enzymes have a great sensitivity and a relatively brief life-time [1]. The relatively short lifetime of enzymes and their sensibility to change in the environment (pH, temperature, mechanical stress, etc.) tends to limit their biotechnological application. The increase of the lifetime and stability of enzymes are crucial to widen usage of enzymes. Improvement in enzyme stability can reduce the amount of enzyme required, can extend the lifetime of enzymes and can increase the reuse of enzymes [2][3][4][5][6][7]. Enzyme immobilization to the surface or onto the inner cavities of greater structures with adsorption or covalent linkage is an effective strategy to increase its lifetime [2,3]. Covalent linkage between the enzyme molecule and carrier material can reduce the unfolding mechanism of ternary structure of enzyme molecule and increase the stability of enzyme [4]. During the last decade there is a growing interest in minimized-size enzyme carriers [8,9].Single enzyme nanocapsules (SEN), or single protein nanocapsules (SPN) mean that a single protein molecule is covered with a few nanometer thick polymer layer [10][11][12][13][14][15] (Figure 1: Structure). This spatial polymer layer is thin and porous and allows the diffusion of substrate molecules to the active centre of the enzyme. Single enzyme nanoparticles involve the advantages of the multi-point covalent attachment [4] and closing of molecules onto inner cavities [16]. This technique needs a special polymerization step: in situ polymerization starting from the previously modified surface of the protein molecules ("Grafting from" method The quaternary protein structures (e.g. tetrameric haemoglobin molecules), as a functional unit does not change during the preparation of the single protein nanocapsules, i.e. covering enzymes by a thin polymeric layer (Figure 1: Structure). It has been proved that single enzyme nanocapsules, using organic/inorganic hybrid layer [10,12,13,14] organic acrylic copolymer [11,15], hyperhranched polymer layer [18] or superparamagnetic layer [19,20], can essentially stabilize enzymes. 58(Sup), pp. 11-16, 2014 DOI:10.3311 The nano-capsule around the enzymes is multifunctional (Figure 1: Functions). Single protein nanocapsules have 1) stabilization function a) mechanical stability, when under mechanical stress (circular stirring) the single enzyme nanocapsules are more stable than natural enzymes (enzymes without nano-layer) [12,13,14]; b) heat stability: when at extremely high temperature (80°C) single enzyme nanocapsules have greater stability than natural enzymes [12,13,14]. c) pH-stability: at extremely acidic (pH = 1.5) or alkaline (pH = 12.0) pH-values the activity of single enzyme nanocapsules are not reduced essentially, whi...

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Conjugation of enzyme on superparamagnetic nanogels covered with carboxyl groups

Cited by 35 publications

References 28 publications

Carbon dioxide/methanol conversion cycle based on cascade enzymatic reactions supported on superparamagnetic nanoparticles

Carbon dioxide/methanol conversion cycle based on cascade enzymatic reactions supported on superparamagnetic nanoparticles

Efficient immobilization of lipase from Candida rugosa by entrapment into poly(N-isopropylacrylamide-co-itaconic acid) hydrogels under mild conditions

Single Haemoglobin Nanocapsules as Test Materials for Artificial Blood

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