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:8/15/2017)... Aug. 15 2017   ivWatch LLC , a medical device ... therapy, today announced receipt of its ISO 13485 Certification, the global ... International Organization for Standardization (ISO®). ... ivWatch Model 400 Continuous Monitoring device for the early detection of ... "This is an important milestone ...
(Date:5/23/2017)...  Hunova, the first robotic gym for the rehabilitation and functional motor ... Genoa, Italy . The first 30 robots will be ... USA . The technology was developed and patented at the ... spin-off Movendo Technology thanks to a 10 million euro investment from entrepreneur ... ...
(Date:4/19/2017)... 19, 2017 The global military ... is marked by the presence of several large global ... by five major players - 3M Cogent, NEC Corporation, ... for nearly 61% of the global military biometric market ... the global military biometrics market boast global presence, which ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... ... of a complex biological network, a depiction of a system of linkages and ... Dmitry Korkin, PhD, associate professor of computer science at Worcester Polytechnic Institute (WPI) ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... United States multicenter, prospective clinical study that demonstrates the accuracy of the ... of identifying clinically significant acute bacterial and viral respiratory tract infections by ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... the first-ever genomics analysis platform specifically designed for life science researchers to ... of pioneering researcher Rosalind Franklin, who made a major contribution to the ...
(Date:10/11/2017)... ... October 11, 2017 , ... Personal eye wash is a basic first aid supply ... a time. So which eye do you rinse first if a dangerous substance enters both ... Duo Eye Wash with its unique dual eye piece. , “Whether its dirt and ...
Breaking Biology Technology: