Topic
Immobilized enzyme
About: Immobilized enzyme is a research topic. Over the lifetime, 15282 publications have been published within this topic receiving 401860 citations.
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TL;DR: PGA from Escherichia coli, immobilized onto agarose activated with glycidol (glyoxyl-agarose), has been used for the design of a novel one-pot synthesis of Cephamandole in aqueous medium and without isolation of intermediates.
91 citations
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TL;DR: The results of these studies indicate that l -DOPA production using tyrosinase immobilized on NaA or CaA is feasible and much superior to the stability of the enzyme when immobilization on other supports.
91 citations
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TL;DR: The synthesis, characterization and use of a composite material made of a renewable source and metallic nanoparticles for biosensing applications, and the results showed that GOx was attached to the surface of the NCC nanocomposite.
Abstract: We describe the synthesis, characterization and use of a composite material made of a renewable source and metallic nanoparticles for biosensing applications. Nanocrystalline cellulose (NCC) is a product isolated from natural cellulose fibers, which is of approximately 100 nm long and 10 nm wide in size. We augmented the surface area and tailored the chemical affinity of NCC by optimally dressing it with gold nanoparticles (AuNPs). The deposition of AuNPs on NCC was controlled by using cationic polyethylenimine (PEI) at different pHs. AuNPs were thiol-functionalized using different linkers prior to enzyme immobilization. The enzyme (glucose oxidase or GOx) was conjugated on the composite by carbodiimide coupling, and subsequent activation of linker-carboxylic acid group. Our results showed that GOx was attached to the surface of the NCC nanocomposite. Moreover, the amount of GOx loaded onto the support depended on the length of the thiol-linker used. The lower value (20.3 mg/mg of support) was obtained with the longer thiol-linker (11 carbon chain) compared to 25.2 mg/mg of support for the smaller thiol-linker (3 carbon chain).
91 citations
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29 Jul 1980
TL;DR: An asymmetric semipermeable membrane was used to measure an organic ingredient such as glucose contained in blood or serum with high sensitivity in a short time and moreover has a prominent durability as discussed by the authors.
Abstract: An electrochemical measuring apparatus which essemtially comprises an asymmetric semipermeable membrane mounted on an immobilized enzyme membrane of an enzyme electrode, said asymmetric semipermeable membrane being essentially formed of a thin semipermeable layer exposed to the outside for contact with a liquid to be measured and an inner adjacent thick porous layers, and can measure an organic ingredient such as glucose contained in blood or serum with high sensitivity in a short time and moreover has a prominent durability.
91 citations
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TL;DR: The immobilized laccase not only can be operated magnetically, but also exhibits remarkably improved catalytic capacity and stability properties for various parameters, such as pH, temperature, reuse, and storage time, which can provide economic advantages for large-scale biotechnological applications of laccases.
Abstract: BACKGROUND: Immobilized enzymes provide many advantages over free enzymes including repeated or continuous reuse, easy separation of the product from reaction media, easy recovery of the enzyme, and improvement in enzyme stability. In order to improve catalytic activity of laccase and increase its industrial application, there is great interest in developing novel technologies on laccase immobilization. RESULTS: Magnetic Cu2+-chelated particles, prepared by cerium-initiated graft polymerization of tentacle-type polymer chains with iminodiacetic acid (IDA) as chelating ligand, were employed for Pycnoporus sanguineus laccase immobilization. The particles showed an obvious high adsorption capacity of laccase (94.1 mg g(-1) support) with an activity recovery of 68.0% after immobilization. The laccase exhibited improved stability in reaction conditions over a broad temperature range between 45 degrees C and 70 degrees C and an optimal pH value of 3.0 after being adsorbed on the magnetic metal-chelated particles. The value of the Michaelis constant (K-m) of the immobilized laccase (1.597 mmol L-1) was higher than that of the free one (0.761 mmol L-1), whereas the maximum velocity (V-max) was lower for the adsorbed laccase. Storage stability and temperature endurance of the immobilized laccase were found to increase greatly, and the immobilized laccase retained 87.8% of its initial activity after 10 successive batch reactions. CONCLUSION: The immobilized laccase not only can be operated magnetically, but also exhibits remarkably improved catalytic capacity and stability properties for various parameters, such as pH, temperature, reuse, and storage time, which can provide economic advantages for large-scale biotechnological applications of laccase. (c) 2007 Society of Chemical Industry.
91 citations