Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Speed and Power of X-Ray Laser Helps Unlock Molecular Mysteries

27.07.2012
New Nanocrystallography Technique Shines Light on Biomolecules in Action

By outrunning a laser’s path of destruction, an international research team has created 3D images of fragile but biologically important molecules inside protein nanocrystals. Using the Linac Coherence Light Source (LCLS), a powerful X-ray laser at the SLAC National Accelerator Laboratory in Menlo Park, Calif., the scientists fired femtosecond (one quadrillionth of a second) bursts of light at a stream of tumbling molecules, obliterating them as they pass, but not before capturing otherwise illusive images of their crystalline structures.

An overview and early results of this new imaging technique will be presented at the 2012 meeting of the American Crystallographic Association (ACA), which takes place July 28 – Aug. 1 in Boston, Mass.

“These laser pulses are so brief that we are able to outrun the radiation’s damaging effects,” said John C.H. Spence of Arizona State University, one of more than 70 international researchers from institutions including SLAC; DESY, the German Electron Synchrotron; and the Max-Planck Institute in Heidelberg, Germany.

“Using this so-called ‘diffract-then-destroy’ approach, our research team recorded about a hundred scattering patterns per second from protein nanocrystals,” said Spence. “This is an important step toward the making of movies of biomolecules at work.”
In traditional crystallography, a beam of X-rays first interacts with a crystal and then appears on a photo-detector as diffraction spots of greater and lesser intensity. These patterns encode the density of electrons in the crystal, enabling scientists to determine the three-dimensional position of atoms, chemical bonds, and other information. To obtain this information, the crystal is frozen, to reduce radiation damage, and placed on a rotating mount and bombarded with X-rays as its orientation is changed. A scattering pattern is slowly built up and the 3D structure can eventually be deduced.

This traditional method of using frozen molecules, however, prevents observation of the molecules at work in their native liquid environment at room temperature.

To obtain images of these molecules in the more natural state, the researchers sent the protein nanocrystals streaming in a single-file micron-sized droplet beam (rather like an ink-jet printer) in vacuum across the X-ray beam, in a method developed at Arizona State University.

Next they fired incredibly brief bursts of X-ray laser light, about 100 times each second, at the molecules in the droplet beam, and detected the scattered X-ray patterns from each particle before the intensity of the beam blasted them apart. The researchers were able to combine these millions of snapshots to build up 3D models of the molecules with atomic-scale resolution.

One particular molecule that was studied this way was Photosystem 1-ferredoxin, which is the chemical powerhouse that drives photosynthesis. The molecules for this experiment were made in the laboratory of Arizona State University researcher Petra Fromme.

Photosystem 1 harnesses sunlight to split water to make the oxygen we breathe, absorb carbon dioxide, and produce sugars, which maintains our biosphere. These molecules were studied “in action” by exciting them with a pulse of green laser light (to mimic the effect of sunlight falling on a leaf) a few microseconds before taking their X-ray snapshot. Each snapshot then became one frame of a movie. By changing the delay between green pulse and X-ray pulse, the researchers could create a 3D movie of a biomolecule in action.

“Many other groups we are supporting now are applying the method to other proteins, such as enzymes, drug molecule targets, and imaging chemical reactions as they develop along the liquid jet,” said Spence. “The important thing was to get atomic-resolution snapshot images from nanocrystals at room temperature without radiation damage.”

A complete listing of the collaborating research institutions follows:

• Center for Free-Electron Laser Science, DESY, Hamburg, Germany
• Photon Science, DESY, Hamburg, Germany
• Department of Chemistry and Biochemistry, Arizona State University, Tempe
• Department of Physics, Arizona State University
• Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Sweden
• Department of Chemistry, Biochemistry, and Biophysics, Göteborg University, Sweden
• Max Planck Advanced Study Group, Center for Free Electron Laser Science (CFEL), Hamburg, Germany
• Max-Planck-Institut für medizinische Forschung, Heidelberg, Germany
• PULSE Institute and SLAC National Accelerator Laboratory, Menlo Park, Calif.
• LCLS, SLAC National Accelerator Laboratory
• CEA, Institut de Biologie et de Technologies de Saclay, France
• European XFEL GmbH, Hamburg, Germany
• Department of Physics, Cornell University, Ithaca, New York
• Max-Planck-Institut für Kernphysik
• Lawrence Livermore National Laboratory, Livermore, Calif.
• PNSensor GmbH, München, Germany
• Max-Planck-Institut Halbleiterlabor, München, Germany
• Advanced Light Source, Lawrence Berkeley National Laboratory
• University of Hamburg,
• Max-Planck-Institut für extraterrestrische Physik, Garching, Germany
This news release was prepared for the American Crystallographic Association (ACA) by the American Institute of Physics (AIP).
MORE INFORMATION ABOUT THE 2012 ACA MEETING
The ACA is the largest professional society for crystallography in the United States, and this is its main meeting. All scientific sessions, workshops, poster sessions, and events will be held at the Westin Waterfront Hotel in Boston, Mass.
USEFUL LINKS:
Main meeting website: http://www.amercrystalassn.org/2012-meeting-homepage
Meeting program: http://www.amercrystalassn.org/2012-tentative-program
Meeting abstracts: http://www.amercrystalassn.org/app/sessions
Exhibits: http://www.amercrystalassn.org/2012-exhibits
ABOUT ACA
The American Crystallographic Association (ACA) was founded in 1949 through a merger of the American Society for X-Ray and Electron Diffraction (ASXRED) and the Crystallographic Society of America (CSA). The objective of the ACA is to promote interactions among scientists who study the structure of matter at atomic (or near atomic) resolution. These interactions will advance experimental and computational aspects of crystallography and diffraction. They will also promote the study of the arrangements of atoms and molecules in matter and the nature of the forces that both control and result from them.

Catherine Meyers
American Institute of Physics
301.209.3088
cmeyers@aip.org
Marcia J. Colquhoun
American Crystallographic Association
716.898.8692
marcia@hwl.buffalo.edu

Catherine Meyers | Newswise Science News
Further information:
http://www.aip.org

More articles from Physics and Astronomy:

nachricht Quantum optics allows us to abandon expensive lasers in spectroscopy
22.11.2017 | Lomonosov Moscow State University

nachricht Nano-watch has steady hands
22.11.2017 | University of Vienna

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Corporate coworking as a driver of innovation

22.11.2017 | Business and Finance

PPPL scientists deliver new high-resolution diagnostic to national laser facility

22.11.2017 | Physics and Astronomy

Quantum optics allows us to abandon expensive lasers in spectroscopy

22.11.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>