Kinetic properties of the periplasmic hydrogenase from Desulfovibrio desulfuricans NCIMB 8372 and use in photosensitized H2-production
| Autor: | Lars H. Eng, Halina Y. Neujahr, Mona B.-M. Lewin |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
chemistry.chemical_classification
Hydrogenase biology Renewable Energy Sustainability and the Environment General Chemical Engineering Organic Chemistry Periplasmic space Electron acceptor biology.organism_classification Photochemistry Pollution Porphyrin Desulfovibrio Inorganic Chemistry chemistry.chemical_compound Fuel Technology Enzyme Reaction rate constant chemistry Enzyme kinetics Waste Management and Disposal Biotechnology |
| Zdroj: | Journal of Chemical Technology & Biotechnology. 56:317-324 |
| ISSN: | 1097-4660 0268-2575 |
| DOI: | 10.1002/jctb.280560316 |
| Popis: | The periplasmic hydrogenase (hydrogen: ferricytochrome-c3 oxido-reductase EC 1.12.2.1) from Desulfovibrio desulfuricans (NCIMB 8372) was isolated and the catalytic properties of the enzyme determined with different electron mediators. In the direction of H2-oxidation with the physiological electron mediator cytochrome c3, the value of the apparent second order rate constant (kcat/Km) is close to that expected for a diffusion-controlled reaction. In H2-production however, the value of kcat/Km with cytochrome c3 is almost 200 times lower. When methyl viologen is used as mediator, the value of kcat/Km is the same in both directions and is intermediate to the values obtained with cytochrome c3. The close to optimum value of kcat/Km in H2-oxidation with cytochrome c3 as electron acceptor is discussed with respect to the biological role of this and related hydrogenases. H2-production occurred with the hydrogenase in a system where the mediator was reduced with either of three photosensitizers (proflavin, 5-deazariboflavin, Zn-tetraphenyl porphyrin sulphonate) upon illumination. The efficiency of different mediators is discussed. |
| Databáze: | OpenAIRE |
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