The enzyme-induced formation of iron hybrid nanostructures with different morphologies.

A new synthesis method for tailor-made iron-hybrid nanoparticles has been carried out for the first time using enzymes, which directly induce the formation of inorganic iron species. The role of the protein was critical for the formation and morphology of the iron nanostructures and, depending on the enzyme, by simple mixing with ammonium iron(ii) sulfate at room temperature and under air, it was possible to obtain, for the first time, well stabilized superparamagnetic iron and iron oxide nanorods, nanosheets and nanorings or even completely amorphous non-magnetic iron structures in the protein network. These iron nanostructure-enzyme hybrids showed excellent results as heterogeneous catalysts in organic chemistry (chemoselective hydrogenation and C-C bonding formation) and environmental remediation processes.

Ultra-Fast Degradation of -Aminophenol by a Nanostructured Iron Catalyst.

Full degradation of -aminophenol in aqueous solution at room temperature by using a heterogeneous nanostructured iron hybrid catalyst in the presence of hydrogen peroxide is described. A nanostructured iron catalyst was prepared by in situ formation of iron carbonate nanorods on the protein network using an aqueous solution of an enzyme, lipase B from (CAL-B). A second kind of iron nanostructured catalyst was obtained by the sunsequent treatment of the hybrid with an aqueous liquid extract of x .

Synthesis of a superparamagnetic ultrathin FeCO nanorods-enzyme bionanohybrid as a novel heterogeneous catalyst.

Herein we report a straightforward synthesis of an ultrathin protein-iron(ii) carbonate nanorods (FeCO3-NRs) heterogeneous bionanohybrid at room temperature and in aqueous media. The enzyme induced the in situ formation of well-dispersed FeCO3 NRs on a protein network. The addition of NaBH4 as a reducing agent allowed us to obtain nanorods (5 × 40 nm) with superparamagnetic properties.

Enantioselective oxidation of galactitol 1-phosphate by galactitol-1-phosphate 5-dehydrogenase from Escherichia coli.

Galactitol-1-phosphate 5-dehydrogenase (GPDH) is a polyol dehydrogenase that belongs to the medium-chain dehydrogenase/reductase (MDR) superfamily. It catalyses the Zn(2+)- and NAD(+)-dependent stereoselective dehydrogenation of L-galactitol 1-phosphate to D-tagatose 6-phosphate. Here, three crystal structures of GPDH from Escherichia coli are reported: that of the open state of GPDH with Zn(2+) in the catalytic site and those of the closed state in complex with the polyols Tris and glycerol, respectively.

Improving Properties of a Novel β-Galactosidase from Lactobacillus plantarum by Covalent Immobilization.

A novel β-galactosidase from Lactobacillus plantarum (LPG) was over-expressed in E. coli and purified via a single chromatographic step by using lowly activated IMAC (immobilized metal for affinity chromatography) supports. The pure enzyme exhibited a high hydrolytic activity of 491 IU/mL towards o-nitrophenyl β-D-galactopyranoside.

Esterase LpEst1 from Lactobacillus plantarum: a novel and atypical member of the αβ hydrolase superfamily of enzymes.

The genome of the lactic acid bacterium Lactobacillus plantarum WCFS1 reveals the presence of a rich repertoire of esterases and lipases highlighting their important role in cellular metabolism. Among them is the carboxylesterase LpEst1 a bacterial enzyme related to the mammalian hormone-sensitive lipase, which is known to play a central role in energy homeostasis. In this study, the crystal structure of LpEst1 has been determined at 2.

Structure, biochemical characterization and analysis of the pleomorphism of carboxylesterase Cest-2923 from Lactobacillus plantarum WCFS1.

The hydrolase fold is one of the most versatile structures in the protein realm according to the diversity of sequences adopting such a three-dimensional architecture. In the present study, we clarified the crystal structure of the carboxylesterase Cest-2923 from the lactic acid bacterium Lactobacillus plantarum WCFS1 refined to 2.1 Å resolution, determined its main biochemical characteristics and also carried out an analysis of its associative behaviour in solution.