Showing papers by "Manuela M. Pereira published in 2002"
TL;DR: This model of CotA contains all the structural features of a laccase, including the reactive surface-exposed copper center (T1) and two buried copper centers (T2 and T3), and shows a half-life of inactivation at 80 °C of about 4 and 2 h, indicating that CotA is intrinsically highly thermostable.
502 citations
TL;DR: The redox properties of the SQR/QFR proteins are reviewed, stressing out the recent observation of redox-Bohr effect upon haem reduction, observed for the Desulfovibrio gigas and Rhodothermus marinus enzymes, which indicates a direct protonation event at the haems or at a nearby residue.
103 citations
TL;DR: The diversity of channels in haem–copper oxygen reductases exemplifies the plasticity of proton pathways that occurred throughout evolution, and strongly suggests a substantial role for water as the main proton carrier.
37 citations
TL;DR: In this paper, the alkaloids (+)- and (−)-indolizidine 167B were synthesized via radical addition of a carbon radical to a chiral acrylamide.
37 citations
TL;DR: The rotenone sensitive NADH: menaquinone oxidoreductase (NDH-I or complex I) from the thermohalophilic bacterium Rhodothermus marinus has been purified and characterized, indicating the complex integrity as purified.
Abstract: The rotenone sensitive NADH:menaquinone oxidoreductase (NDH-I or complex I) from the thermohalophilic bacterium Rhodothermus marinus has been purified and characterized. Three of its subunits react with antibodies against 78, 51, and 21.3c kDa subunits of Neurospora crassa complex I. The optimum conditions for NADH dehydrogenase activity are 50 degrees C and pH 8.1, and the enzyme presents a KM of 9 microM for NADH. The enzyme also displays NADH:quinone oxidoreductase activity with two menaquinone analogs, 1,4-naphtoquinone (NQ) and 2,3-dimethyl-1,4-naphtoquinone (DMN), being the last one rotenone sensitive, indicating the complex integrity as purified. When incorporated in liposomes, a stimulation of the NADH:DMN oxidoreductase activity is observed by dissipation of the membrane potential, upon addition of CCCP. The purified enzyme contains 13.5 +/- 3.5 iron atoms and approximately 3.7 menaquinone per FMN. At least five iron-sulfur centers are observed by EPR spectroscopy: two [2Fe-2S](2+/1+) and three [4Fe-4S](2+/1+) centers. By fluorescence spectroscopy a still unidentified chromophore was detected in R. marinus complex I.
28 citations
TL;DR: A small protein isolated from the thermohalophilic and strict aerobic bacterium Rhodothermus marinus, which contains a single, homogeneous, trinuclear centre, is investigated and is very sensitive to oxygen, an unexpected characteristic for a protein from an aerobic organism.
15 citations