Mechanism of Nitrate Reduction by Desulfovio desulfuricans Nitrate Reductase - A Theoretical Investigation

The oxidative half-reaction of oxygen atom transfer from nitrate to an MoIV complex has been investigated at various levels of theory. Two models have been used to simulate the enzyme active site. In the second, more advanced model, additional amino acid residues capable of significantly affecting the catalytic efficiency of the enzyme were included. B3LYP/6-31+G*, ONIOM, and orbital-free embedding approaches have been used to construct the potential energy profile and to qualitatively compare the results of a QM/MM study with those obtained by a full quantum mechanical strategy. The study has confirmed the utility of the orbital-free embedding method in the description of enzymatic processe

The role of quantum chemistry in the elucidation of the elementary mechanisms of catalytic processes: From atoms, to surfaces, to enzymes

The recent activity of the laboratory of quantum and computational chemistry of the University of Calabria in the field of catalysis is shortly reviewed. Theoretical determinations of the potential energy profiles for the cyclotrimerization of acetylene catalyzed by bare and supported niobium atom and the reduction mechanism of nitrate to nitrite by nitrate reductase enzyme are presented as examples of studies in which a certain number of investigation methods mostly used in this field, are applied. \ua9 Springer-Verlag 2007