Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Intimate insights into nature’s photosynthetic powerhouse

11.09.2012
Scientists at the Max Planck Institute for Chemical Energy Conversion (MPI CEC) have solved a long-­‐standing puzzle in photosynthesis research.

With the aid of quantum chemistry they were able to provide unexpected insight into the properties of the oxygen evolving complex (OEC). The OEC is the catalyst in plants that splits water using sunlight in order to build carbohydrates, thus powering all life on earth.


Figure (copyright by MPI CEC): The two structures of the core of nature's water oxidizing catalyst Photosystem II, which interconvert by changing bonds between an oxygen and its two manganese bondingpartners; a different spectroscopic signal is produced by eacharrangement.

Its precise structure, which was showing enigmatic spectroscopic behaviour, could now finally be solved with the aid of quantum chemistry. In one of its most studied oxidation states the OEC revealed two types of spectroscopic signals.

These signals could be converted to one another by various treatments, but not in any structurally comprehensible way. Moreover the signals are so complex that a detailed molecular structure could not be deduced. With the aid of theoretical spectroscopic techniques, Dr. Dimitrios Pantazis, scientist at the MPI CEC, and his colleagues were able to show that the two signals are caused by two energetically similar and interconvertible structures of the complex.

The core of the enzyme consists of a partial cubic structure made of manganese, calcium and oxygen (Mn4CaO5 s. figure). "Calculations show, that the two structures differ only by one bond, that swaps between the central oxygen and the two terminal manganese atoms", states Pantazis. This small change has a huge impact on the electronic structure and thus the spectroscopic properties of the molecule. Both structures are almost equal in energy and the bond swapping can happen over a low energetic barrier. Crucially, the scientists at the MPI additionally proved using theoretical simulations that each of the two structures has a distinct spectroscopic signature and that these two signatures have a one-­‐to-­‐one correspondence with the experimentally observed spectroscopic signals.

The deep understanding of the OEC is fundamental in order to further elucidate nature´s mysteries on the oxidation of water, a reaction that plays an essential role for energy research, such as in artificial photosynthesis. After these striking findings, research by Pantazis and his group is currently focused on identifying whether the oxygen atom swapping bonds with the manganese is one of the oxygen atoms released from the enzyme as molecular oxygen.

The new findings will shed light on the kinetics and exchange of water molecules that take part in the reaction, paving the way for a detailed atomic-­‐level understanding of the mechanism of water oxidation.

Published online in Angewandte Chemie International Edition, August 21 http://dx.doi.org/10.1002/anie.201204705

The Max Planck Institute for Chemical Energy Conversion (MPI CEC) in Muelheim an der Ruhr focuses on fundamental chemical reactions that play a role for the storage and conversion of energy. The main objective is to save the energy of sunlight in small, energy rich molecules, and thus make it easily available independently of time and location. In the three departments Heterogeneous Reactions, Molecular Theory and Spectroscopy and Biophysical Chemistry work 75 scientists from more than 20 countries and with their expertise they contribute to a sustainable energy concept.

Dr. Rebekka Loschen | Max-Planck-Institute
Further information:
http://www.cec.mpg.de

More articles from Life Sciences:

nachricht Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>