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| Naji, M. |
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| Motta, Antonella |
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| Aletan, Dirar |
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| Mohamed, Tarek |
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| Ertürk, Emre |
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| Taccardi, Nicola |
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| Kononenko, Denys |
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| Petrov, R. H. | Madrid |
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| Alshaaer, Mazen | Brussels |
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| Bih, L. |
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| Casati, R. |
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| Muller, Hermance |
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| Kočí, Jan | Prague |
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| Šuljagić, Marija |
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| Kalteremidou, Kalliopi-Artemi | Brussels |
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| Azam, Siraj |
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| Ospanova, Alyiya |
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| Blanpain, Bart |
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| Ali, M. A. |
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| Popa, V. |
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| Rančić, M. |
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| Ollier, Nadège |
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| Azevedo, Nuno Monteiro |
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| Landes, Michael |
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| Rignanese, Gian-Marco |
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Moura, José J. G.
Universidade Nova de Lisboa
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (14/14 displayed)
- 2019Biosensor for direct bioelectrocatalysis detection of nitric oxide using nitric oxide reductase incorporated in carboxylated single-walled carbon nanotubes/lipidic 3 bilayer nanocompositecitations
- 2019Biosensor for direct bioelectrocatalysis detection of nitric oxide using nitric oxide reductase incorporated in carboxylated single-walled carbon nanotubes/lipidic 3 bilayer nanocompositecitations
- 2019Third-generation electrochemical biosensor based on nitric oxide reductase immobilized in a multiwalled carbon nanotubes/1-n-butyl-3-methylimidazolium tetrafluoroborate nanocomposite for nitric oxide detectioncitations
- 2014Influence of respiratory substrate in carbon steel corrosion by a Sulphate Reducing Prokaryote model organismcitations
- 2011Crystal structure of the zinc-, cobalt-, and iron-containing adenylate kinase from Desulfovibrio gigas: a novel metal-containing adenylate kinase from Gram-negative bacteria
- 2011Crystal structure of the zinc-, cobalt-, and iron-containing adenylate kinase from Desulfovibrio gigas: a novel metal-containing adenylate kinase from Gram-negative bacteriacitations
- 2011Bacterial diversity and influence of SRB presence on metal behaviour within the oil & gas industry
- 2009Isolation and characterization of a new Cu-Fe protein from Desulfovibrio aminophilus DSM12254citations
- 2009Cobalt-, zinc- and iron-bound forms of adenylate kinase (AK) from the sulfate-reducing bacterium Desulfovibrio gigas: purification, crystallization and preliminary X-ray diffraction analysiscitations
- 2005Superoxide reductase from the syphilis spirochete Treponema pallidum: crystallization and structure determination using soft X-rayscitations
- 2004Overexpression and purification of Treponema pallidum rubredoxin; kinetic evidence for a superoxide-mediated electron transfer with the superoxide reductase neelaredoxincitations
- 2003Formation of a stable cyano-bridged dinuclear iron cluster following oxidation of the superoxide reductases from treponema pallidum and Desulfovibrio vulgaris with K3Fe(CN)6citations
- 2001Tungsten-containing formate dehydrogenase from Desulfovibrio gigas: metal identification and preliminary structural data by multi-wavelength crystallographycitations
- 2000Evidence for antisymmetric exchange in cuboidal [3Fe-4S]+ clusterscitations
Places of action
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article
Evidence for antisymmetric exchange in cuboidal [3Fe-4S]+ clusters
Abstract
<p>Iron-sulfur clusters with [3Fe-4S] cores are widely distributed in biological systems. In the oxidized state, designated [3Fe-4S]<sup>+</sup>, these electron-transfer agents have an electronic ground state with S = 1/2 , and they exhibit EPR signals centered at g = 2.01. It has been established by Mossbauer spectroscopy that the three iron sites of the cluster are high-spin Fe<sup>3+</sup>, and the general properties of the S = 1/2 ground state have been described with the exchange Hamiltonian H(exch) = J<sub>12</sub>S<sub>1</sub>·S<sub>2</sub> + J<sub>23</sub>S<sub>2</sub>·S<sub>3</sub> + J<sub>13</sub>S<sub>1</sub>·S<sub>3</sub>. Some [3Fe-4S]<sup>+</sup> clusters (type 1) have their g-values confined to the range between g = 2.03 and 2.00 while others (type 2) exhibit a continuous distribution of g-values down to g ≃ 1.85. Despite considerable efforts in various laboratories no model has emerged that explains the g-values of type 2 clusters. The 4.2 K spectra of all [3Fe-4S]<sup>+</sup> clusters have broad features which have been simulated in the past by using <sup>57</sup>Fe magnetic hyperfine tensors war anisotropies that are unusually large for high-spin ferric sites. It is proposed here that antisymmetric exchange, H(AS) = d·(S<sub>1</sub> x S<sub>2</sub> + S<sub>2</sub> x S<sub>3</sub> + S<sub>3</sub> x S<sub>1</sub>), is the cause of the g-value shifts in type 2 clusters. We have been able to fit the EPR and Mossbauer spectra of the 3Fe clusters of beef heart aconitase and Desulfovibrio gigas ferredoxin II by using antisymmetric exchange in combination with distributed exchange coupling constants J<sub>12</sub>, J<sub>13</sub>, and J<sub>23</sub> (J-strain). While antisymmetric exchange is negligible for aconitase (which has a type 1 cluster), fits of the ferredoxin II spectra require |d| ≃ 0.4 cm<sup>-1</sup>. Our studies show that the data of both proteins can be fit using the same isotropic <sup>57</sup>Fe magnetic hyperfine coupling constant for the three cluster sites, namely a = -18.0 MHz for aconitase and a = -18.5 MHz for the D. gigas ferredoxin. The effects of antisymmetric exchange and J-strain on the Mossbauer and EPR spectra are discussed.</p>