Menico Rizzi

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D-amino acid oxidase is the prototype of the FAD-dependent oxidases. It catalyses the oxidation of D-amino acids to the corresponding alpha-ketoacids. The reducing equivalents are transferred to molecular oxygen with production of hydrogen peroxide. We have solved the crystal structure of the complex of D-amino acid oxidase with benzoate, a competitive(More)
BACKGROUND Pyruvate kinase (PK) plays a major role in the regulation of glycolysis. Its catalytic activity is controlled by the substrate phosphoenolpyruvate and by one or more allosteric effectors. The crystal structures of the non-allosteric PKs from cat and rabbit muscle are known. We have determined the three-dimensional structure of the allosteric type(More)
Laccase is a multicopper blue oxidase that couples the four-electron reduction of oxygen with the oxidation of a broad range of organic substrates, including phenols and arylamines. The enzyme is the object of intense biotechnological research, due to its employment in bioremediation of soils and water as well as in other biotechnological applications. We(More)
Kynurenine aminotransferases are pyridoxal-5'-phosphate-dependent enzymes, which catalyze the synthesis of kynurenic acid, a highly neuroactive metabolite whose impairment is associated with a number of severe brain disorders. Crystallographic studies of these enzymes from different organisms, including humans, have revealed distinctive structural traits of(More)
Department of General and Inorganic Chemistry, UniVersity of Parma, Via G.P. Usberti 17/A 43100, Parma, Italy, National Institute for Biosystems and Biostructures, Rome, Italy, Department of Medicinal Chemistry and Institute for Structural Biology & Drug DiscoVery, Virginia Commonwealth UniVersity, Richmond, Virginia 23298-0540, Department of Pharmaceutics,(More)
Nicotinamide mononucleotide adenylyltransferase (NMNAT), a member of the nucleotidyltransferase alpha/beta-phosphodiesterases superfamily, catalyzes a universal step (NMN + ATP = NAD + PP(i)) in NAD biosynthesis. Localized within the nucleus, the activity of the human enzyme is greatly altered in tumor cells, rendering it a promising target for cancer(More)
BACKGROUND Nicotinamide adenine dinucleotide (NAD(+)) is an essential cofactor involved in fundamental processes in cell metabolism. The enzyme nicotinamide mononucleotide adenylyltransferase (NMN AT) plays a key role in NAD(+) biosynthesis, catalysing the condensation of nicotinamide mononucleotide and ATP, and yielding NAD(+) and pyrophosphate. Given its(More)
The three-dimensional structure of the complex formed by two plasma proteins, transthyretin and retinol-binding protein, was determined from x-ray diffraction data to a nominal resolution of 3.1 angstroms. One tetramer of transthyretin was bound to two molecules of retinol-binding protein. The two retinol-binding protein molecules established molecular(More)
NADP is essential for biosynthetic pathways, energy, and signal transduction. In living organisms, NADP biosynthesis proceeds through the phosphorylation of NAD with a reaction catalyzed by NAD kinase. We expressed, purified, and characterized Bacillus subtilis NAD kinase. This enzyme represents a new member of the inorganic polyphosphate [poly(P)]/ATP NAD(More)