Controlled release of protein drugs from newly developed amphiphilic polymer-based microparticles composed of nanoparticles.

A novel formulation of biodegradable microparticles was developed for the sustained release of peptide and protein drugs. The microparticles were formed by the aggregation of protein nanoparticles through water-in-oil (W/O) emulsion-lyophilization and subsequent solid-in-oil-in-water (S/O/W) emulsion-solvent evaporation. Amphiphilic copolymers were used as an emulsifier in the W/O emulsion and matrix of the microparticles.

Laccase-mediated oxidative degradation of the herbicide dymron.

The present study reports the successful and effective degradation of the persistent herbicide dymron catalyzed by the oxidative enzyme laccase in the presence of a reaction mediator (a laccase/mediator system). Using 2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as the mediator, over 90% of dymron was degraded within 24 h, while the half-life of dymron is 50 days in soil. The results suggested that oxidation of dymron resulted in the production of decomposed compounds with a single aromatic ring.

A recombinant Escherichia coli whole cell biocatalyst harboring a cytochrome P450cam monooxygenase system coupled with enzymatic cofactor regeneration.

A cytochrome P450cam monooxygenase (P450cam) system from the soil bacterium Pseudomonas putida requires electron transfer among three different proteins and a cofactor, nicotinamide adenine dinucleotide (NADH), for oxygenation of its natural substrate, camphor. Herein, we report a facile way to significantly enhance the catalytic efficiency of the P450cam system by the coupling of its native electron transfer system with enzymatic NADH regeneration catalyzed by glycerol dehydrogenase (GLD) in Escherichia coli whole cell biocatalysts. Recombinant E.

Biodegradation of phenolic environmental pollutants by a surfactant-laccase complex in organic media.

Oxidative degradation of phenolic environmental pollutants in organic media was investigated using a laccase complexed with surfactants. The catalytic activity of the surfactant-laccase complex in isooctane was markedly enhanced by appropriately adjusting the water content of the reaction medium using reverse micelles. The surfactant-laccase complex showed little activity towards the oxidative reaction of bisphenol A in water-saturated isooctane (i.

Functionalization of the cytochrome P450cam monooxygenase system in the cell-like aqueous compartments of water-in-oil emulsions.

The functionalization of the cytochrome P450cam monooxygenase system, which requires electron transfer among three different proteins, was investigated in the micro-scale aqueous compartments of stable water-in-oil (W/O) emulsions formed with the nonionic surfactant tetraethylene glycol dodecyl ether. Neither an organic-aqueous biphasic system nor a non-emulsified organic-aqueous solution containing the same amount of surfactant showed substantial hydroxylation of camphor, a natural substrate of P450cam, whereas substantial monooxygenation activity was detected when stable aqueous compartments were provided by the formation of W/O emulsions. Since the camphor hydroxylation in W/O emulsions was modest, we explored the integration of an enzymatic NADH regeneration system in order to effectively provide a reducing equivalent.

Factors affecting the oxidative activity of laccase towards biphenyl derivatives in homogeneous aqueous-organic systems.

Catalytic oxidation of biphenyl derivatives was investigated using laccase in a homogeneous aqueous-organic system. A thermostable laccase from Trametes sp. showed the highest catalytic activity for the oxidation of 4-hydroxybiphenyl (4-HB) at a reaction temperature of 60 degrees C when dimethylsulfoxide (DMSO) was employed as a co-solvent.

Control of water content by reverse micellar solutions for peroxidase catalysis in a water-immiscible organic solvent.

The water content of a water-immiscible can be controlled using reverse micelles. We applied this reverse micellar system to improve the enzymatic activity of a surfactant-manganese peroxidase complex in toluene. Increasing the water content in toluene to 2 vol% using the reverse micelles resulted in the great improvement (10-fold) of the peroxidase activity.

Electron-transfer reactions and functionalization of cytochrome P450cam monooxygenase system in reverse micelles.

Enzyme-based electron-transfer reactions involved in the cytochrome P450 monooxygenase system were investigated in nanostructural reverse micelles. A bacterial flavoprotein, putidaredoxin reductase (PdR), was activated and shown to be capable of catalyzing the electron transport from NADH to electron-carrier proteins such as cytochrome b5 (tCyt-b5) and putidaredoxin (Pdx) in reverse micelles. Ferric tCyt-b5 in reverse micelles was effectively converted to its ferrous form by the exogenous addition of separately prepared reverse micellar solution harboring PdR and NADH.

Activation of lignin peroxidase in organic media by reversed micelles.

Activation of lignin peroxidase (LIP) in an organic solvent by reversed micelles was investigated. Bis(2-ethylhexyl)sulfosuccinate sodium salt (AOT) was used as a surfactant to form a reversed micelle. Lyophilized LIP from an optimized aqueous solution exhibited no enzymatic activity in any organic solvents examined in this study; however, LIP was catalytically active by being entrapped in the AOT reversed micellar solution.