Encontrados 11 documentos, a visualizar página 1 de 2
Gd(III) chelates as NMR probes of protein-protein interactions. Case study: rub...
Almeida, Rui M.; Geraldes, Carlos F. G. C.; Pauleta, Sofia R.; Moura, José J. G.Inorganic Chemistry 50(21):10600-7 ; Two cyclen-derived Gd probes, [Gd-DOTAM](3+) and [Gd-DOTP](5-) (DOTAM = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetamide; DOTP = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methylenephosphonate)), were assessed as paramagnetic relaxation enhancement (PRE)-inducing probes for characterization of protein-protein interactions. Two proteins, Desulfovibrio gigas rubre...
The tetranuclear copper active site of nitrous oxide reductase: the CuZ center
Dell’Acqua, Simone; Pauleta, Sofia R.; Moura, Isabel; Moura, José J. G.J Biol Inorg Chem (2011) 16:183–194 DOI 10.1007/s00775-011-0753-3 ; This review focuses on the novel CuZ center of nitrous oxide reductase, an important enzyme owing to the environmental significance of the reaction it catalyzes, reduction of nitrous oxide, and the unusual nature of its catalytic center, named CuZ. The structure of the CuZ center, the unique tetranuclear copper center found in this enzyme, ope...
Artefacts induced on c-type haem proteins by electrode surfaces
Sousa, Patrícia M. Paes de; Pauleta, Sofia R.; Gonçalves, M. Lurdes Simões; Pettigrew, Graham W.; Moura, Isabel; Moura, José J. G.J Biol Inorg Chem (2011) 16:209–215 DOI 10.1007/s00775-010-0717-z ; In this work it is demonstrated that the characterization of c-type haem containing proteins by electrochemical techniques needs to be cautiously performed when using pyrolytic graphite electrodes. An altered form of the cytochromes, which has a redox potential 300 mV lower than that of the native state and displays peroxidatic activity, can b...
A new CuZ active form in the catalytic reduction of N2O by nitrous oxide reduct...
Dell’Acqua, Simone; Pauleta, Sofia R.; Sousa, Patrícia M. Paes de; Monzani, Enrico; Casella, Luigi; Moura, José J. G.; Moura, IsabelJ Biol Inorg Chem (2010) 15:967–976 DOI 10.1007/s00775-010-0658-6 ; The final step of bacterial denitrification, the two-electron reduction of N2O to N2, is catalyzed by a multi-copper enzyme named nitrous oxide reductase. The catalytic centre of this enzyme is a tetranuclear copper site called CuZ, unique in biological systems. The in vitro reconstruction of the activity requires a slow activation in the pres...
Electron transfer complex between nitrous oxide reductase and cytochrome c552 f...
Moura, Isabel; Moura, José J. G.; Pauleta, Sofia R; Monzani, Enrico; Pereira, Alice S.; Casella, Luigi; Dell’Acqua, SimoneBiochemistry. 2008 Oct 14;47(41):10852-62. doi: 10.1021/bi801375q ; The multicopper enzyme nitrous oxide reductase (N 2OR) catalyzes the final step of denitrification, the two-electron reduction of N 2O to N 2. This enzyme is a functional homodimer containing two different multicopper sites: CuA and CuZ. CuA is a binuclear copper site that transfers electrons to the tetranuclear copper sulfide CuZ, the catalyt...
Enzymatic activity mastered by altering metal coordination spheres
Moura, Isabel; Moura, José J. G.; Pauleta, Sofia R.J Biol Inorg Chem (2008) 13:1185–1195 DOI 10.1007/s00775-008-0414-3 ; Metalloenzymes control enzymatic activity by changing the characteristics of the metal centers where catalysis takes place. The conversion between inactive and active states can be tuned by altering the coordination number of the metal site, and in some cases by an associated conformational change. These processes will be illustrated using h...
Benefits of membrane electrodes in the electrochemistry of metalloproteins: med...
Sousa, P. M. Paes de; Pauleta, Sofia R.; Rodrigues, D.; Gonçalves, M. L. Simões; Pettigrew, G. W.; Moura, Isabel; Moura, José J. G.J Biol Inorg Chem. 2008 Jun;13(5):779-87. doi: 10.1007/s00775-008-0365-8 ; A comparative study of direct and mediated electrochemistry of metalloproteins in bulk and membrane-entrapped solutions is presented. This work reports the first electrochemical study of the electron transfer between a bacterial cytochrome c peroxidase and horse heart cytochrome c. The mediated catalysis of the peroxidase was analysed b...
NMR assignment of the apo-form of a Desulfovibrio gigas protein containing a no...
Pauleta, Sofia R.; Duarte, Américo G; Carepo, Marta S.; Pereira, Alice S.; Tavares, Pedro; Moura, Isabel; Moura, José J. G.Biomol NMR Assign (2007) 1:81–83 DOI 10.1007/s12104-007-9022-3 ; We report the 98% assignment of the apo-form of an orange protein, containing a novel Mo–Cu cluster isolated from Desulfovibrio gigas. This protein presents a region where backbone amide protons exchange fast with bulk solvent becoming undetectable. These residues were assigned using 13C-detection experiments.
Mediated catalysis of Paracoccus pantotrophus cytochrome c peroxidase by P. pan...
Sousa, P. M. Paes de; Pauleta, Sofia R.; Gonçalves, M. L. Simões; Pettigrew, Graham W.; Moura, Isabel; Moura, José J. G.J Biol Inorg Chem (2007) 12:691–698 DOI 10.1007/s00775-007-0219-9 ; This work reports the direct electrochemistry of Paracoccus pantotrophus pseudoazurin and the mediated catalysis of cytochrome c peroxidase from the same organism. The voltammetric behaviour was examined at a gold membrane electrode, and the studies were performed in the presence of calcium to enable the peroxidase activation. A formal reducti...
Kinetics studies of the superoxide-mediated electron transfer reactions between...
Auchère, Françoise; Pauleta, Sofia R.; Tavares, Pedro; Moura, Isabel; Moura, José J. G.J Biol Inorg Chem (2006) 11: 433–444 DOI 10.1007/s00775-006-0090-0 ; In this work we present a kinetic study of the superoxide-mediated electron transfer reactions between rubredoxin-type proteins and members of the three different classes of superoxide reductases (SORs). SORs from the sulfate-reducing bacteria Desulfovibrio vulgaris (Dv) and D. gigas (Dg) were chosen as prototypes of classes I and II, respect...
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