Navigation Links
A first direct glimpse of photosynthesis in action
Date:7/11/2014

An international team of researchers, including scientists from the Max Planck Institute for Medical Research in Heidelberg, has just a reported a major step in understanding photosynthesis, the process by which the Earth first gained and now maintains the oxygen in its atmosphere and which is therefore crucial for all higher forms of life on earth.

The researchers report the first direct visualization of a crucial event in the photosynthetic reaction, namely the step in which a specific protein complex, photosystem II, splits water into hydrogen and oxygen using energy provided by light. This is a catalytic process in which the molecules of photosystem II enable and promote the reaction without themselves being consumed. Given the very high sensitivity of photosystem II to radiation damage, the photosynthetic reaction cannot be followed by standard methods of structural investigation such as conventional time-resolved X-ray crystallography. It is, however, amenable to study using the very recently developed method of protein crystallography with free-electron lasers.

In this technique, exceedingly short but extremely intense pulses of X-rays are used to gather data from very small crystals. The pulses are so short, in fact, that they "outrun" most effects of radiation damage, including the complete annihilation of the sample that inevitably follows on much longer time scales. The technique is thus well suited for collecting data from highly sensitive systems such as this catalyzed splitting of water in photosynthesis. Crucial to the process is a special site within the photosystem-II-molecule that contains four manganese atoms and one calcium atom. The experimental measurements show large structural changes in this particular metal cluster, which elongates significantly.

The measurements were made at the SLAC National Accelerator Laboratory in Stanford, using the short and intense flashes from SLAC's X-ray laser, the Linac Coherent Light Source (LCLS). The international team from 18 different institutions was led by Petra Fromme (Arizona State University) and included, in addition to the Heidelberg group, members from SLAC and the University of Hamburg. The Heidelberg team contributed expertise on injecting a thick slurry (suspension) of crystals as a micron-sized jet of particles to be intersected by the femtosecond X-ray pulses from the free electron laser. Crucial to this injection was the design, manufacture and operation of a temperature-controlled, anti-settling device to allow uninterrupted sample injection over the course of many hours.

This work is significant not only for its direct relevance to understanding photosynthesis, but also because it directly proves the feasibility of performing dynamic X-ray diffraction measurements at room temperature - in particular using free-electron lasers - to study mechanisms of the fast enzyme reactions that are characteristic of so many processes in living organisms.


'/>"/>

Contact: Dr. John Wray
wray@mpimf-heidelberg.mpg.de
49-622-148-6277
Max-Planck-Gesellschaft
Source:Eurekalert

Related biology news :

1. First drug candidate from NIH program acquired by biopharmaceutical company
2. Rockefeller scientists first to reconstitute the DNA replication fork
3. Archaeopteryx plumage: First show off, then take-off
4. A first: Scientists show bacteria can evolve a biological timer to survive antibiotics
5. First positive results toward a therapeutic vaccine against brain cancer
6. Drug shows promise for the first time against metastatic melanoma of the eye
7. Super bananas -- world first human trial
8. Findings point toward one of first therapies for Lou Gehrigs disease
9. Alcohol abuse damage in neurones at a molecular scale identified for first time
10. Spectrum Health among first to implant neurostimulator for epilepsy
11. Public gets first view of a live vampire squid and other deep-sea cephalopods
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/31/2016)... March 31, 2016   ... or the "Company") LegacyXChange is excited to ... its soon to be launched online site for trading ... ) will also provide potential shareholders a sense ... technology to an industry that is notorious for fraud. ...
(Date:3/23/2016)... March 23, 2016 ... Sicherheit Gesichts- und Stimmerkennung mit Passwörtern ... (NASDAQ: MESG ), ein führender Anbieter ... Unternehmen mit SpeechPro zusammenarbeitet, um erstmals dessen ... wird die Möglichkeit angeboten, im Rahmen mobiler ...
(Date:3/21/2016)... 2016 Unique technology combines ... superior security   Xura, Inc. ... secure digital communications services, today announced it is working ... enterprise customers, particularly those in the Financial Services Sector, ... authentication within a mobile app, alongside, and in combination ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... , June 23, 2016 A person commits ... the crime scene to track the criminal down. ... U.S. Food and Drug Administration (FDA) uses DNA evidence to ... Sound far-fetched? It,s not. The FDA has ... to support investigations of foodborne illnesses. Put as simply as ...
(Date:6/23/2016)... Calif. , June 23, 2016  The Prostate Cancer Foundation ... increasingly precise treatments and faster cures for prostate cancer. Members of the Class ... across 15 countries. Read More About the Class of ... ... ...
(Date:6/23/2016)... (PRWEB) , ... June 23, 2016 , ... ... today announced the launch of the Supplyframe Design Lab . Located in ... to explore the future of how hardware projects are designed, built and brought ...
(Date:6/23/2016)... 23, 2016 Apellis Pharmaceuticals, Inc. today ... trials of its complement C3 inhibitor, APL-2. The ... ascending dose studies designed to assess the safety, ... injection in healthy adult volunteers. Forty ... a single dose (ranging from 45 to 1,440mg) ...
Breaking Biology Technology: