Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Extreme x-ray pulses create unique image of intact virus

03.02.2011
They are entirely too small to be seen even with the most powerful microscope.

But now an international research team has managed to capture an image of an intact virus and a membrane structure from a photosynthetic bacterium with the aid of extremely intensive and ultra-short x-ray pulses from the world’s first free electron laser. This new advance in structural biology is being published today in two articles in the journal Nature.

The findings for the two studies pave the way for studies of biological structures at the molecular level, including viruses, individual cells, cell organelles, and living bacteria. The technology enhances the possibilities of imaging individual biological molecules that are too small to study even with the most powerful microscopes.

- Biologists have long dreamed of being able to capture the image of viruses, single-cell organisms, and bacteria without having to section, freeze, or mark them with metals, as is necessary in electron microscopy. Our studies show that it is really possible to create images with the aid of extremely intensive and ultra-short x-ray pulses that would otherwise destroy everything in their path, says Professor Janos Hajdu from the Division of Molecular Biophysics, Uppsala University.

Together with his colleague Henry Chapman, he has co-directed the international research team, which also includes Inger Andersson’s team from the Swedish University of Agricultural Sciences, SLU. The entire international group is currently at Stanford for new experiments with the advanced free electron laser.

X-ray diffraction has been an irreplaceable instrument in identifying biological structures, but this technology requires crystallized samples of sufficient size. Many particles are therefore packed in crystals. For single particles the x-ray dose needs to be increased so much that the particle is destroyed, especially if it comes from biological material. A number of years ago it was suggested that extremely short pulses from a so-called free electron laser would be able to create an image before the particle had time to be damaged. It is this method (read more about the technology below) that is now being tested on biological material.

In the first study, the method was tested on Mimivirus, the world’s largest known virus, discovered as recently as 1992. It is larger than some single-cell organisms and the only virus that can be infected by a virus of its own. Its size and special surface structure entails that it cannot be studied using conventional imaging methods such as electron microscopy or x-ray crystallography.

In the other study the team shows that x-ray pulses can also be used to study the structure of vitally important membrane proteins – in this case a protein complex that captures sunlight and converts it to energy in photosynthesizing organisms, here a photosynthetic bacterium. Membrane proteins are essential to life processes, not only as energy converters but also as the cell’s transporters and receptors for drugs – but they are incredibly hard to study using conventional methods. The new technology means that huge “blank patches” in structural biology will now be accessible for study at the level of the atom for the first time.

About the technology: The world’s first free electron laser in the hard x-ray area – the Linac Coherent Light Source (LCLS), at Stanford Linear Accelerator Center (SLAC) – has a light intensity that surpasses conventional synchrotrons by a billion times, so intensive that it can cut through steel. A single pulse that is focused on a micrometer-size point contains as much energy as all sunlight hitting the earth focused to a square millimeter. The light pulses are extremely short (50-70 femtoseconds, 1 fs = 10-15 sec), which means that can replicate the image of a micrometer-size virus, before it is heated up to 100,000 degree centigrade and is destroyed. LCLS came into use in October 2009, and the studies in question were performed in December that year.

References:

Hajdu et al. Single mimivirus particles intercepted and imaged with an X-ray laser. Nature, doi:10.1038/nature09748

Chapman et al. Femtosecond X-ray protein nanocrystallography. Nature, doi:10.1038/nature09750

For more information, please contact Janos Hajdu (currently at Stanford), mobile: +46 (0)70-425 01 94, janos.hajdu@icm.uu.se or Inger Andersson (also currently at Stanford), mobile: +46 (0)70-520 81 01, inger.andersson@molbio.slu.se

Uppsala University -- quality, knowledge, and creativity since 1477
World-class research and outstanding education of global benefit to society, business, and culture.

Uppsala University is one of northern Europe's highest ranked academic institutions.

Anneli Waara | Uppsala universitet
Further information:
http://www.uu.se

More articles from Physics and Astronomy:

nachricht Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz

nachricht New functional principle to generate the „third harmonic“
16.02.2017 | Laser Zentrum Hannover e.V.

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>