Featured Research

from universities, journals, and other organizations

Groundbreaking x-ray snapshots of active photosynthesis

Date:
June 4, 2012
Source:
Ume universitet
Summary:
Scientists are opening new avenues to understand photosynthesis and create artificial photosynthesis. Using x-ray analysis, they have managed to see the structure of molecules under conditions where photosynthesis can occur, and they have also found that calcium plays a critical role in decomposing water.

Working with researchers in the US and Germany, Johannes Messinger at Ume University is opening new avenues to understand photosynthesis and create artificial photosynthesis. Using x-ray analysis, they have managed to see the structure of molecules under conditions where photosynthesis can occur, and they have also found that calcium plays a critical role in decomposing water.

The solar energy reaching Earth is 5,000 times greater than all energy consumption in the world. To be able to exploit this source of energy and store it would help solve humans' more and more acute energy problems.

Two major research projects at Ume University are devoted to developing artificial photosynthesis by imitating plants' extremely successful way of making use of energy from the sun. Both projects ("solar fuels" and "artificial leaf") are directed by Johannes Messinger, a professor at the Department of Chemistry, Ume University.

To be able to create an "artificial leaf," researchers need to study the ingenious system that plants have used for millions of years on earth. We need to answer two crucial questions: What molecules are necessary to break down water in plant photosynthesis? What is their role, that is, how do they function and when?

In collaboration with American and German colleagues (there are a total of 36 authors of the publication), Johannes Messinger has devised a tool to investigate plant photosynthesis systems while they are active. Using ultra-short x-ray flashes, they have succeeded in performing structural analyses of isolated photosynthesis molecules from plant photosystem II at room temperature. The movement of the atoms was registered for a period of 50 femtoseconds (10-15 seconds). The equipment used, an x-ray free-electron laser, is located at Stanford University in the US.

Normally the structure of molecules is determined by using x-ray flashes in frozen samples. But because the x-ray flashes used in this experiment are so brief, they do not last long enough to disrupt the photosystem during measurement. This opens new possibilities of discovering structures and studying how the system reacts in the leaf under natural conditions when they are actively carrying out photosynthesis.

"Our objective is to study how oxygen atoms form a bridge to create oxygen molecules when water is broken down. Until now, it has been impossible to study this phase of photosynthesis in detail," says Johannes Messinger.

In his efforts to construct an artificial leaf that can convert water to hydrogen and oxygen, the Ume scientist, together with collaborative partners at the Max Planck Institute for Bioinorganic Chemistry, have discovered another building block. It is already known that calcium ions are involved in decomposing water and that a system that has no calcium cannot produce oxygen. But the researchers now wanted to find out whether calcium is necessary to keep the structure of the photosystem stable (especially manganese ions) or whether calcium is needed in the reaction itself.

The research team managed to remove the calcium ions from the whole molecule complex and then study the structure using EPR spectroscopy, electron paramagnetic resonance.

"We could see that the molecule complex, which consists of four manganese ions held together by five oxygen atoms, did not change its structure after we had removed the calcium ions. This indicates that calcium must play an extremely important role in the water decomposition reaction," says Johannes Messinger.

Proceedings of the National Academy of Sciences is publishing the major advances in ultra-rapid x-ray studies, and in Journal of Biological Chemistry, Johannes Messinger is a co-author of the article on the role of calcium in photosynthesis.


Story Source:

The above story is based on materials provided by Ume universitet. Note: Materials may be edited for content and length.


Journal References:

  1. T. Lohmiller, N. Cox, J.-H. Su, J. Messinger, W. Lubitz. The basic properties of the electronic structure of the oxygen-evolving complex of photosystem II are not perturbed by Ca2 removal. Journal of Biological Chemistry, 2012; DOI: 10.1074/jbc.M112.365288
  2. Jan Kern, et. al. Room Temperature Femtosecond X-ray Diffraction of Photosystem II Microcrystals. Proceedings of the National Academy of Sciences, 2012

Cite This Page:

Ume universitet. "Groundbreaking x-ray snapshots of active photosynthesis." ScienceDaily. ScienceDaily, 4 June 2012. <www.sciencedaily.com/releases/2012/06/120604111115.htm>.
Ume universitet. (2012, June 4). Groundbreaking x-ray snapshots of active photosynthesis. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2012/06/120604111115.htm
Ume universitet. "Groundbreaking x-ray snapshots of active photosynthesis." ScienceDaily. www.sciencedaily.com/releases/2012/06/120604111115.htm (accessed October 22, 2014).

Share This



More Plants & Animals News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Reuters - US Online Video (Oct. 21, 2014) Police in Gary, Indiana are using cadaver dogs to search for more victims after a suspected serial killer confessed to killing at least seven women. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
White Lion Cubs Unveiled to the Public

White Lion Cubs Unveiled to the Public

Reuters - Light News Video Online (Oct. 21, 2014) Visitors to Belgrade zoo meet a pair of three-week-old lion cubs for the first time. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com
White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins