Molecular hydrogen is discussed as promising renewable energy source and attractive alternative to fossil fuels. Many microorganisms exploit the beneficial properties of hydrogen already since more than two billion years. They accommodate dedicated enzymes that either split or evolve molecular hydrogen according to the specific metabolic requirements of the cell.
These hydrogen-converting biocatalysts are called hydrogenases and occur in nature in different varieties. Most hydrogenases become inactivated or even destroyed in the presence of molecular oxygen. This intrinsic property represents a serious problem regarding biotechnological application. However, some hydrogenases maintain their catalytic activity in the presence of oxygen.
An interdisciplinary team of scientists headed by the UniCat researchers Oliver Lenz and Bärbel Friedrich from Humboldt-Universitaet zu Berlin and Patrick Scheerer and Christian Spahn from Charité - Universitätsmedizin Berlin now succeeded in solving the first X-ray crystal structure of a hydro-genase that produces hydrogen even at atmospheric oxygen concentration.
The X-ray crystal structure allows detailed insights into the three-dimensional architecture of the enzyme and its metal cofactors which participate in catalysis. The results have been published in Nature online (http://dx.doi.org/10.1038/nature10505). Interestingly, the hydrogenase contains a novel iron-sulfur center which acts as an electronic switch in the course of detoxification of detrimental oxygen. With this discovery, the scientists could substantiate the hypothesis that this particular group of hydro-genases is able to convert both, hydrogen and oxygen in a catalytic manner. During catalysis, oxygen becomes reduced to harmless water.
The new results are particularly relevant for fundamental research. More-over, also the biotechnological application of hydrogenases, e.g. solar-driven hydrogen production by photosynthetic microorganisms and enzyme-driven biological fuel cells, may profit from the new findings. Furthermore, it is anticipated that the novel iron-sulfur center will inspire chemists to design model compounds with improved catalytic properties.UniCat
Published in: Fritsch, J., P. Scheerer, S. Frielingsdorf, S. Kroschinsky, B. Friedrich, O. Lenz & C. M. Spahn. The crystal structure of an oxygen-tolerant hydrogenase uncovers a novel iron-sulphur centre. Nature doi: 10.1038/nature10505 (2011)
For further information, please contact:
Dr. Oliver Lenz, Institut für Biologie / Mikrobiologie der Humboldt-Universität zu Berlin, Germany, Phone: +49 (0) 30/2093 8173, E-mail: firstname.lastname@example.orgDr. Martin Penno, UniCat Cluster of Excellence, Public Relations Officer
Stefanie Terp | idw
For bacteria, the neighbors co-determine which cell dies first: The physiology of survival
17.07.2019 | Technische Universität München
Atacama Desert: Some lichens can meet their need for water from air humidity
17.07.2019 | Technische Universität Kaiserslautern
Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.
Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...
For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.
Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...
An international research group led by scientists from the University of Bayreuth has produced a previously unknown material: Rhenium nitride pernitride. Thanks to combining properties that were previously considered incompatible, it looks set to become highly attractive for technological applications. Indeed, it is a super-hard metallic conductor that can withstand extremely high pressures like a diamond. A process now developed in Bayreuth opens up the possibility of producing rhenium nitride pernitride and other technologically interesting materials in sufficiently large quantity for their properties characterisation. The new findings are presented in "Nature Communications".
The possibility of finding a compound that was metallically conductive, super-hard, and ultra-incompressible was long considered unlikely in science. It was...
An interdisciplinary research team at the Technical University of Munich (TUM) has built platinum nanoparticles for catalysis in fuel cells: The new size-optimized catalysts are twice as good as the best process commercially available today.
Fuel cells may well replace batteries as the power source for electric cars. They consume hydrogen, a gas which could be produced for example using surplus...
The fly agaric with its red hat is perhaps the most evocative of the diverse and variously colored mushroom species. Hitherto, the purpose of these colors was...
24.06.2019 | Event News
29.04.2019 | Event News
17.04.2019 | Event News
17.07.2019 | Life Sciences
17.07.2019 | Physics and Astronomy
17.07.2019 | Physics and Astronomy