Catalytic asymmetric reduction reactions have long been the preserve of the transition metal catalyst. Inspired by the myriad efficient enzyme-catalysed reduction reactions routine in biological systems, chemists have recently begun to design chiral metal-free organocatalysts that employ synthetic dihydropyridine NADH analogues as the hydride source with impressive results. Recent developments ...

Pyrolytic graphite particles modified with hydrogenase and an NAD(+)/NADH cycling enzyme provide a modular heterogeneous catalyst system for regeneration of oxidised or reduced nicotinamide cofactors using H(2) and H(+) as electron source or sink. Particles can be tuned for cofactor supply under different conditions by appropriate choice of hydrogenase.

OvoA is an iron(II) dependent sulfoxide synthase which catalyzes the first step in ovothiol A biosynthesis. This enzyme sulphurizes the C5 position of the imidazole side chain of L-histidine. We report the substrate specificity profile of this catalyst and present data which indicate that OvoA catalysis follows an thiol-ene type mechanism.

A solid-phase strategy using lipase as a biomolecular scaffold to produce a large amount of Cu(2+)-metalloenzyme is proposed here. The application of this protocol on different 3D cavities of the enzyme allows creating a heterogeneous artificial metallolipase showing chimeric catalytic activity. The artificial catalyst was assessed in Diels-Alder cycloaddition reactions and cascade reactions sh...

beta-Glucosidase from Flavobacterium meningosepticum (Fbgl) (also known as Chryseobacterium meningosepticum) has been classified as a member of the family 3 glycohydrolases. It is a retaining enzyme involving a two-step, double-displacement mechanism. D247 was shown to function as the nucleophile of the enzymatic reaction [Li, Y.-K., Chir, J., and Chen, F.-Y. (2001) Biochem. J. 355, 835-840]. H...

phospholipase a1 is known as an effective catalyst for hydrolysis of various phospholipids in enzymatic vegetable oil degumming. immobilization is one of the most efficient strategies to improve its activity, recovery and functional properties. in this study, chitosan-co-polyethylene oxide (90:10) nanofibrous mat was successfully fabricated and modified with atmospheric plasma at different time...

The complete electro-oxidation of glycerol to CO2 is performed through an oxidation cascade using a hybrid catalytic system combining a recombinant enzyme, oxalate decarboxylase from Bacillus subtilis, and an organic oxidation catalyst, 4-amino-TEMPO. This system is capable of electrochemically oxidizing glycerol at a carbon electrode collecting all 14 electrons per molecule.

Combinatorial assembly and variation of promoters on a single expression plasmid allowed the balance of the catalytic steps of a three enzyme (l-AAD, HIC, FDH) cascade in E. coli. The designer cell catalyst quantitatively transformed l-amino acids to the corresponding optically pure (R)- and (S)-α-hydroxy acids at up to 200 mM substrate concentration.

An N-terminal and C-terminal truncated recombinant α2-6-sialyltransferase cloned from Photobacterium sp. JH-ISH-224, Psp2,6ST(15-501)-His(6), was shown to be an efficient catalyst for one-pot three-enzyme synthesis of sialyl Tn (STn) antigens and derivatives containing natural and non-natural sialic acid forms.

The pH optima of family 11 xylanases are well correlated with the nature of the residue adjacent to the acid/base catalyst. In xylanases that function optimally under acidic conditions, this residue is aspartic acid, whereas it is asparagine in those that function under more alkaline conditions. Previous studies of wild-type (WT) Bacillus circulans xylanase (BCX), with an asparagine residue at ...