Synthesis of fucosyllactose using α-L-fucosidases GH29 from infant gut microbial metagenome.

Fucosyl-oligosaccharides (FUS) provide many health benefits to breastfed infants, but they are almost completely absent from bovine milk, which is the basis of infant formula. Therefore, there is a growing interest in the development of enzymatic transfucosylation strategies for the production of FUS. In this work, the α-L-fucosidases Fuc2358 and Fuc5372, previously isolated from the intestinal bacterial metagenome of breastfed infants, were used to synthesize fucosyllactose (FL) by transfucosylation reactions using p-nitrophenyl-α-L-fucopyranoside (pNP-Fuc) as donor and lactose as acceptor.

The E state of FeMoco: Hydride Formation versus Fe Reduction and a Mechanism for H Evolution.

The iron-molybdenum cofactor (FeMoco) is responsible for dinitrogen reduction in Mo nitrogenase. Unlike the resting state, E , reduced states of FeMoco are much less well characterized. The E state has been proposed to contain a hydride but direct spectroscopic evidence is still lacking.

A model for dinitrogen binding in the E state of nitrogenase.

Molybdenum nitrogenase is one of the most intriguing metalloenzymes in nature, featuring an exotic iron-molybdenum-sulfur cofactor, FeMoco, whose mode of action remains elusive. In particular, the molecular and electronic structure of the N-binding E state is not known. In this study we present theoretical QM/MM calculations of new structural models of the E state of molybdenum-dependent nitrogenase and compare to previously suggested models for this enigmatic redox state.

Computational Mechanistic Study of [MoFeS] Cubanes for Catalytic Reduction of Nitrogenase Substrates.

Molybdenum-dependent nitrogenase is the most active biological catalyst for dinitrogen reduction. This reaction is catalyzed by a [MoFeSC] cofactor (FeMoco). FeMoco can be described as a double-cubane, with [MoFeS] and [FeS] parts, bound via an interstitial carbide and three bridging sulfides.

QM/MM calculations reveal a bridging hydroxo group in a vanadium nitrogenase crystal structure.

A new 1.2 Å crystal structure of vanadium nitrogenase, isolated under turnover conditions, recently revealed a light atom ligand (OH or NH) replacing the bridging S2B sulfide of the FeV cofactor. QM/MM calculations on the new structure now reveal the light-atom ligand to be a bridging hydroxo group, probably derived from water binding to the cofactor.