Institutes | Max Planck Institutes | MPI for Bioinorganic Chemistry

The necessity for a sustainable energy economy beyond fossil fuels and nuclear energy has nowadays found broad consensus. The transformation of the present technologies is a huge challenge for society as a whole, which will dominate the following decades politically and economically. Basic research can deliver insights, which will lead to novel and essential technologies. With the foundation of the Max Planck Institute for Chemical Energy Conversion the MPG has set the course for this important development.

2012

How small vampires dilute human blood

2012, Max Planck Institute for Chemical Energy Conversion

Knipp, Markus

Nitrophorins comprise a unique class of metal containing proteins originating from blood sucking bugs. On bite they transport the gaseous signaling molecule nitric oxide (NO) into the tissue of a host. Application of various spectroscopic techniques reveals the molecular mechanisms that lead to specific NO delivery. Recent investigations demonstrate that the NO coordinating iron center is also able to produce NO from nitrite. Because NO causes the opening of blood vessels (vasodilatation), the understanding of these native NO transporting systems is of major pharmacological interest.

2011

Insight into Nature's fascinating power station: the water-splitting system of photosynthesis

2011, Max Planck Institute for Chemical Energy Conversion

Ames, W.; Pantazis, D. A.; Neese, F.

The unique process of photosynthesis, which converts sunlight into storable chemical energy, sustains life on Earth. To understand how Nature achieves this feat is one of the greatest challenges for science – and of great importance for our future energy supply. Unfortunately even the structure of the water oxidase, one of the principal components of photosynthesis, has not yet been resolved unambiguously. By combining spectroscopy and quantum chemistry deep insight into this central process could be attained.

2010

Light as a regulatory environmental factor

2010, Max Planck Institute for Chemical Energy Conversion

Gärtner, Wolfgang

Sunlight regulates many environmental processes, but in particular the high-energy blue light region represents a threat that has to be detected with high confidence and to which organisms have to respond in an appropriate physiological manner. Based on in vitro investigations that reveal the molecular processes of blue light (BL)-sensitive photoreceptors, their regulatory function for microbial communities is outlined. Interestingly, the presence of BL photoreceptors coincides with blue light-induced photolyases that repair DNA lesions, and also with proteins involved in the iron metabolism pathway.

2009

The electron structure of "simple" iron complexes: a very complex problem

2009, Max Planck Institute for Chemical Energy Conversion

Khusniyarov, Marat; Weyhermüller, Thomas; Bill, Eckhard; Wieghardt, Karl

We present a relatively simple inorganic system of two co-crystallized synthetic iron complexes with remarkably complex electronic structures, owing to the large number of possible redox states at the metal centers as well as at the redox-active ligands. For the first time an unprecedented complex reversible phase transition at 235 K is observed. With this model the exploration of complex processes, which may happen in similar ways in biological systems, is demonstrated by combined experimental techniques.

2008

Why do plants not get sunburn?

2008, Max Planck Institute for Chemical Energy Conversion

Holzwarth, Alfred R.; Miloslavina, Yuliya; Müller, Marc G.; Szczepaniak, Malwina; Ostroumov, Evgenyi; Slavov, Chavdar

Plants exhibit highly efficient protection mechanisms that prevent the damaging influence of high excessive light intensities. In these processes the excess energy absorbed in the light-harvesting complexes of the photosystems is converted into heat. Recent studies allowed to assign these protection mechanisms to specific components of the photosynthetic apparatus. In order to gain insight into these regulation mechanisms special methods of ultrafast fluorescence spectroscopy were developed which – in combination with the use of mutants – allowed to study molecular details of the protection mechanisms.

2007

Radical Complexes as functional models for metalloenzymatic catalysis

2007, Max Planck Institute for Chemical Energy Conversion

Chaudhuri, Phalguni; Wieghardt, Karl; Weyhermüller, Thomas; Bothe, Eberhard; Bill, Eckhard

Significant efforts were directed towards the design and testing of phenol-containing ligands for synthesizing radical-containing transition metal complexes as potential candidates for oxidative catalysis of organic substrates like alcohols, amines and 2-aminophenol with oxygen from air. Functional models for different copper-oxidases, such as Galactose Oxidase (GO), Amine Oxidases (AO) and Phenoxazinone Synthase (PHs) are reported. In most of the cases, an "on-off" mechanism of the radicals without redox participation from the metal centers seems to be operative in the catalysis involving such metal-iminosemiquinone radical complexes.

2006

Production and Consumption of Molecular Hydrogen by Hydrogenases

2006, Max Planck Institute for Chemical Energy Conversion

van Gastel, Maurice; Reijerse, Eduard J.; Lubitz, Wolfgang

Molecular hydrogen (H₂) is an important energy carrier in environmentally-friendly applications, e.g. clean fuel cells, which are under development worldwide. However, presently the large scale production of hydrogen from water and sunlight is still a major challenge. In nature anaerobic bacteria use this molecule as energy source. The two major classes of hydrogenases, the enzymes that catalyze the production or the splitting of H₂, were investigated by means of EPR and FTIR spectroscopy and quantumchemical calculations to elucidate the reaction mechanism.

2005

Spectroscopic Models for Paramagnetic Active Sites in Photosystem II

2005, Max Planck Institute for Chemical Energy Conversion

Bill, Eckhard

Photosynthesis in green plants and some bacteria is based on the efficient function of most sophisticated molecular machines. Like in a factory assembly line, sunlight is captured, stabilized and converted into chemical energy - which then is used for chemical reactions and to oxidize water. Particularly the last step is very difficult and the most demanding task in chemical terms. The whole process of photosynthesis is based on charge separation at specific redox centers of the photosystem and careful charge conduction and control. To avoid immediate loss of the energy by 'electrical short circuit' (and thus charge recombination) the redox potentials of the redox-active centers and the spatial arrangement of the elements in the charge transfer path were carefully tuned by evolution. We are particularly interested in the interaction and mutual control of specific redox-active groups in the so-called "reaction center" (which is the site of water oxidation) and how one could measure their interaction by physical means. The final goal of such a research program is understanding the natural systems in full detail and depth so that blueprints for technical designs and applications can be deduced. In the project presented here a series of isostructural dimeric manganese complexes with tethered organic radicals was synthesized. For the first time these compounds could mimic the paramagnetic interaction of the manganese cluster and a tyrosin Y_z^• radical in the S₂Y_z^• state of photosystem PS II. The state S₂Y_z^• is an artificially stabilized intermediate in the chain of oxidation events in the reaction center of PS II which may control the flow of electrons during catalysis. Since both sites, the manganese cluster and the radicals in S₂Y_z^• as well as in the models, carry spin and magnetic moment, their magnetic dipole interaction could be detected by using electron paramagnetic resonance techniques (EPR spectroscopy) and susceptibility measurements. For the first time the conditions of long-range interactions between mixed-valence manganese clusters and organic radicals like in PS II could be systematically explored as a function of known molecular structures. The EPR results are most relevant for the understanding of real systems and EPR distance measurements in biochemical molecules.

2004

Photosynthetic water oxidation

2004, Max Planck Institute for Chemical Energy Conversion

Messinger, Johannes

Photosynthetic water oxidation is essential for sustaining the ecosystem on earth. This process splits water into protons, chemically bound electrons and molecular oxygen. Thereby this reaction is also an important reference for the development of artificial systems for solar-induced production of hydrogen and oxygen from water. This brief article summarizes the current state of knowledge and gives examples for biophysical experiments that are underway at the MPI for Bioinorganic Chemistry in order to fully understand this fascinating reaction.