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:3/11/2016)... , March 11, 2016 ... new market research report "Image Recognition Market by Technology ... (Marketing and Advertising), by Deployment Type (On-Premises and Cloud), ... To 2022", published by MarketsandMarkets, the global market is ... to USD 29.98 Billion by 2020, at a CAGR ...
(Date:3/9/2016)... 9, 2016 Nigeria ... more than 23,000 public service employees either did not ... their salary unlawfully.    --> Nigeria ... that more than 23,000 public service employees either did ... receiving their salary unlawfully.    --> DERMALOG, ...
(Date:3/3/2016)... , March 3, 2016  2016FLEX, organized ... this week highlighting advancements in flexible, hybrid and ... record setting attendance - have gathered for short ... fast-growing field of electronics. The Flex Conference celebrates ... point for companies, R&D organizations, and universities contributing ...
Breaking Biology News(10 mins):
(Date:4/28/2016)... , April 28, 2016 ... reports the Company,s CEO  was featured in an ... Enter When VCs Fear To Tread: http://www.lifescienceleader.com/doc/accelerators-enter-when-vcs-fear-to-tread-0001 ... magazine is an essential business journal ... from emerging biotechs to Big Pharmas. Their content ...
(Date:4/28/2016)... ... April 28, 2016 , ... Morris Midwest ( ... for regional manufacturers at its Maple Grove, Minnesota technical center, May 11-12. ... and Trumpf. Almost 20 leading suppliers of tooling, accessories, software and other ...
(Date:4/27/2016)... , ... April 27, 2016 , ... ... Touch screen mobile devices with fingerprint recognition for secure access, voice recognition for ... a few ways consumers are interacting with biometrics technology today. But if ...
(Date:4/27/2016)... ... April 27, 2016 , ... ... has joined the company as an Expert Consultant. Mr. Clark was formerly ... and managing the development of small molecule monographs based on analytical methods. ...
Breaking Biology Technology: