With the help of experimental studies on molecular level, researchers are acquiring increased knowledge on how plants form oxygen from water molecules. An international research team has now found a way to visualise this reaction in high-resolution images of photosystem II. The results are being published today in the journal Nature.
"This work is a breakthrough. It paves way to study step-by-step the formation of an oxygen molecule by two water molecules," says Johannes Messinger, professor in Biological Chemistry at Umeå University in Sweden and one of the leading researchers in the project.
The structure of the complex in photosystem II where oxygen is evolving in a light-activated state. Water molecules are shown as blue spheres, the four manganese ions in purple, the calcium ion in green and the bridging oxygen ions in red. The blue mesh is the experimental electron density, and the blue sticks are the protein side chains holding the catalytic complex.
Credit: Johannes Messinger, Umeå University
Plants play a crucial role in mitigating climate change. They use sunlight to remove greenhouse gas carbon dioxide from the atmosphere and convert it into biomass. At the same time, plants also produce the oxygen we breathe by splitting water into oxygen and biologically bonded hydrogen. This process may prove even more important to save the climate, because if we understand water splitting completely, we can develop technology that produces hydrogen gas (fuel) from solar energy, which is much more efficient than how plants can produce biomass.
In collaboration with an international team of researchers, professor Johannes Messinger, who recently joined the Molecular Biomimetics Programme at Uppsala University, has now found a way to visualise this reaction in high-resolution images using the X-ray free-electron laser at SLAC National Accelerator Laboratory at Stanford University.
In the study, published in the current issue of the journal Nature, the research consortium developed new ways to grow microcrystals of photosystem II - the protein complex in plants that is responsible for producing oxygen from water using sunlight. These microcrystals were then placed on a conveyor belt using technology akin to ink-jet printing. On the belt, the crystals were illuminated with laser flashes of green light, to start the water splitting reaction cycle. During this process, the protein complex undergoes a series of steps before the oxygen process starts.
The structure of these activated states were subsequently visualised by hitting the crystals with ultrafast X-ray pulses (10-15s). The present scientific article describes how the authors were able to resolve the structural differences between two of the states in photosystem II that are involved in water splitting.
"We are now all set to tackle the final mysteries of how plants make oxygen - a dream has come true," says Johannes Messinger.
In order to make the promising progress, research teams from Lawrence Berkeley National Laboratory, Stanford University in the US, Humboldt University in Berlin, Umeå University and Uppsala University in Sweden have collaborated for five years.
Ingrid Söderbergh | EurekAlert!
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
Pollen taxi for bacteria
18.07.2018 | Technische Universität München
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
18.07.2018 | Life Sciences
18.07.2018 | Materials Sciences
18.07.2018 | Health and Medicine