Scientists at the Max Planck Institute for Chemical Energy Conversion (MPI CEC) and the Ruhr-Universität Bochum (RUB) have found through spectroscopic investigations on a hydrogen-producing enzyme that the environment of the catalytic site acts as an electron reservoir in the enzyme.
Thus, it can very efficiently produce hydrogen, which has great potential as a renewable energy source. The research team describes their results in the journal "Angewandte Chemie".
Producing hydrogen with enzymes
The system analysed constitutes an enzyme that catalyses the formation and conversion of hydrogen. In its centre it has a double-iron core, and is therefore also called [FeFe] hydrogenase. Hydrogenases are of great interest for energy research, since they can efficiently produce hydrogen. However, new catalysts can only be developed given a deep understanding of their mode of action.
Electron transfer in several steps
In hydrogen production, two electrons get together with two protons. The research team showed that, as expected, the first electron is initially transferred to the iron centre of the enzyme. The second transfer on the other hand is to an iron-sulphur cluster that is located in the periphery. It thus forms a temporary storage for the second electron. This "super-reduced" state may be responsible for the extremely high efficiency of the hydrogenase. Subsequently both electrons are transferred in one step from the enzyme to the protons, so that hydrogen is generated. "Only the use of two different spectroscopic techniques made the discovery possible", says Agnieszka Adamska, a doctoral student at MPI CEC who carried out the spectroscopic studies.
10,000 molecules of hydrogen per second
"Up to 10,000 molecules of hydrogen per second can be generated by a single [FeFe] centre", says Camilla Lambertz, a postdoc at the RUB who prepared the biological samples for the project. The enzyme is thus among the most efficient hydrogenases and is therefore also being intensively investigated by biologists and chemists with a view to achieving environmentally friendly hydrogen production. The complete mechanism of hydrogen formation is, however, complex and several steps need to be clarified. Next, the researchers at MPI CEC and the Ruhr-Universität Bochum aim to use sensitive spectroscopic methods to locate the proton to which the two electrons are transferred. This negatively charged hydrogen atom (hydride) reacts with another proton to form hydrogen. Inspired by the [FeFe] hydrogenase, the researchers would like to develop their own hydrogen-producing catalysts that could be used for the generation of hydrogen.
A. Adamska, A. Silakov, C. Lambertz, O. Rüdiger, T. Happe, E. Reijerse, W. Lubitz (2012): Identification and Characterization of the "Super-Reduced" State of the H-Cluster in [FeFe] Hydrogenase: A New Building Block for the Catalytic Cycle?, Angewandte Chemie International Edition, doi: 10.1002/anie.201204800
Further informationDr. Rebekka Loschen, Max Planck Institute for Chemical Energy Conversion,
Editor: Dr. Rebekka Loschen, MPI
Dr. Camilla Lambertz | EurekAlert!
Further reports about: > Angewandte Chemie > Biotechnology > Electron transfer > Energy Conversion > Hydrogen > Hydrogenase > MPI > Max Planck Institute > RUB > Ruhr-Universität > Temporary > chemical engineering > hydrogen-producing enzyme > natural > sensitive spectroscopic methods > spectroscopic technique
When Air is in Short Supply - Shedding light on plant stress reactions when oxygen runs short
23.03.2017 | Institut für Pflanzenbiochemie
WPI team grows heart tissue on spinach leaves
23.03.2017 | Worcester Polytechnic Institute
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
23.03.2017 | Life Sciences
23.03.2017 | Power and Electrical Engineering
23.03.2017 | Earth Sciences