Sol‐gel immobilization of serine proteases for application in organic solvents

Laccase from Trametes versicolor 51639 was encapsulated on the nanoscale. The laccase nanogel was prepared by polyacrylamide encapsulation as a result of N‐acryloxysuccinimide modification and in situ polymerization. Size‐exclusion chromatography, fluorescence resonance energy transfer, dynamic light scattering, and transmission electron microscopy were employed to characterize the laccase nanogel. Higher thermal, pH, and storage stability and organic‐solvent tolerance of the laccase nanogel were indicated without activity loss. Moreover, the laccase nanogel was used to synthesize naphthoquinones from hydroquinones with a 10–15 % greater overall yield than that of native laccase.

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“…In addition, an intensified intramolecular hydrogen bond within laccase can stabilize the conformation. [12,18] …”

Section: Organic-solvent Tolerance Experimentsmentioning

confidence: 98%

The Preparation and Characterization of a Laccase Nanogel and Its Application in Naphthoquinone Synthesis

et al. 2013

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“…Other strategies generally change the surrounding physicochemical environment of the enzyme. Immobilization by covalent bonding or entrapment into inorganic or polymeric supports has often improved enzyme stability and sometimes enhanced specific activity of enzymes in organic solvents (St. Clair and Navia, 1992;Gill et al, 1999;Murakami et al, 2003;Ruiz et al, 2000;van Unen et al, 2001;Wang et al, 2001). Solubilization of enzymes in organic solvents by chemical modification or extraction with surfactants has also produced increases in enzyme activity over unaltered enzymatic preparations (Altreuter et al, 2003;Kwon et al, 2000).…”

Section: Introductionmentioning

confidence: 97%

Salt‐activation of nonhydrolase enzymes for use in organic solvents

Morgan

Clark

2003

Biotech & Bioengineering

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Enzymatic reactions are important for the synthesis of chiral molecules. One factor limiting synthetic applications of enzymes is the poor aqueous solubility of numerous substrates. To overcome this limitation, enzymes can be used directly in organic solvents; however, in nonaqueous media enzymes usually exhibit only a fraction of their aqueous-level activity. Salt-activation, a technique previously demonstrated to substantially increase the transesterification activity of hydrolytic enzymes in organic solvents, was applied to horse liver alcohol dehydrogenase, soybean peroxidase, galactose oxidase, and xanthine oxidase, which are oxidoreductase and oxygenase enzymes. Assays of the lyophilized enzyme preparations demonstrated that the presence of salt protected enzymes from irreversible inactivation. In organic solvents, there were significant increases in activity for the salt-activated enzymes compared to nonsalt-activated controls for every enzyme tested. The increased enzymatic activity in organic solvents was shown to result from a combination of protection against inactivation during the freeze-drying process and other as-yet undetermined factors.

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“…When the stability and durability of the immobilized HRP were analyzed, the cinnamoylated derivatives functioned as suitable supports for immobilizing peroxidase and to be suitable for industrial application of the enzyme [51,52]. Sol-gel encapsulation of biological catalysts in silicate glasses has experienced a swift expansion due to the synthetic ease of enzyme entrapment procedures and to the significantly enhanced stability of the entrapped enzyme [101][102][103]. The activity of immobilized HRP has been employed for the asymmetric oxidation of thioanisole in acetonitrile with H 2 O 2 .…”

Section: Immobilization On Organic Supportsmentioning

confidence: 99%