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:1/26/2017)...  Crossmatch, a leading provider of security and identity ... combatting fraud, waste and abuse in assistance operations around ... on Disaster Relief conference in Panama City ... and foreign assistance organizations throughout Latin America ... a largely unacknowledged problem in the foreign assistance and ...
(Date:1/24/2017)... 2017 Biopharm Reports has carried out ... of nuclear magnetic resonance spectroscopy (NMR). This involved ... current practices, developments, trends and end-user plans over ... and opportunities. These areas include growth in the ... and innovation requirements, hyphenated NMR techniques, main suppliers ...
(Date:1/21/2017)... Research and Markets has announced the addition of the ... ... voice recognition biometrics market to grow at a CAGR of 19.36% ... present scenario and the growth prospects of the global voice recognition ... considers the revenue generated from the sales of voice recognition biometrics ...
Breaking Biology News(10 mins):
(Date:2/23/2017)... SAN FRANCISCO , Feb. 23, 2017   ... Beyond Type 1, a not-for-profit advocacy and education group ... a grant from Beyond Type 1 to support ViaCyte,s ... and other insulin-requiring diabetes.  For more ... cell-derived cell replacement therapies with a focus on the ...
(Date:2/22/2017)... Feb. 22, 2017  Aratana Therapeutics, Inc. (NASDAQ: PETX), a ... of innovative biopharmaceutical products for companion animals, will host a ... a.m. ET to discuss financial results from the fourth quarter ... Interested participants and investors may access the audio webcast ... ...
(Date:2/22/2017)... (PRWEB) , ... February 22, 2017 , ... Park ... free AFM Luncheon for all SPIE attendees and Park customers ... just one block from the San Jose Convention Center. The luncheon will feature ...
(Date:2/22/2017)... Scientists propose in Nature blocking ... Gaucher and maybe other lysosomal storage diseases as a ... current therapies. An international research team led ... also included investigators from the University of Lübeck in ... 22. The study was conducted in mouse models of ...
Breaking Biology Technology: