Tuning of functional heme reduction potentials in Shewanella fumarate reductases
| Autor: | Caroline S Miles, Miguel Pessanha, Stephen K Chapman, Ricardo O. Louro, Graeme A Reid, David L. Turner, Emma L Rothery, Carlos A. Salgueiro, António V. Xavier |
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| Rok vydání: | 2009 |
| Předmět: |
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Molecular Shewanella Magnetic Resonance Spectroscopy Stereochemistry Biophysics Cytochrome c Group Electrons Heme 010402 general chemistry Photochemistry 01 natural sciences Redox Biochemistry Electrostatic interaction Catalysis 03 medical and health sciences chemistry.chemical_compound Catalytic Domain Redox titration Respiratory enzyme 030304 developmental biology chemistry.chemical_classification 0303 health sciences biology Fumarate Periplasmic space Cell Biology Hydrogen-Ion Concentration biology.organism_classification NMR 0104 chemical sciences Succinate Dehydrogenase Kinetics Enzyme Solubility chemistry Thermodynamics Oxidation-Reduction Protein Binding |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Bioenergetics. 1787(2):113-120 |
| ISSN: | 0005-2728 |
| DOI: | 10.1016/j.bbabio.2008.11.007 |
| Popis: | The fumarate reductases from S. frigidimarina NCIMB400 and S. oneidensis MR-1 are soluble and monomeric enzymes located in the periplasm of these bacteria. These proteins display two redox active domains, one containing four c-type hemes and another containing FAD at the catalytic site. This arrangement of single-electron redox co-factors leading to multiple-electron active sites is widespread in respiratory enzymes. To investigate the properties that allow a chain of single-electron co-factors to sustain the activity of a multi-electron catalytic site, redox titrations followed by NMR and visible spectroscopies were applied to determine the microscopic thermodynamic parameters of the hemes. The results show that the redox behaviour of these fumarate reductases is similar and dominated by a strong interaction between hemes II and III. This interaction facilitates a sequential transfer of two electrons from the heme domain to FAD via heme IV. |
| Databáze: | OpenAIRE |
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