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
A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences