Argonne scientists use lasers to align molecules

May 13, 2008

Protein crystallographers have only scratched the surface of the human proteins important for drug interactions because of difficulties crystallizing the molecules for synchrotron x-ray diffraction.

Scientists at the U.S. Department of Energy's Argonne National Laboratory have devised a way to eliminate the need for crystallization by using lasers to align large groups of molecules.

"Strong laser fields can be used to control the behavior of atoms and molecules," Argonne Distinguished Fellow Linda Young said. "Using x-rays, we can investigate their properties in a totally new way."

Crystallization allows scientists to create a periodic structure that will strongly diffract in specific directions when bombarded with x-rays. From the resulting diffraction pattern, a real-space image can be reconstructed.

However, without crystallization, when x-rays collide with multiple, randomly oriented molecules, they diffract in different directions, making it impossible to create a composite diffraction image, Argonne Physicist Robin Santra said.

Some molecules, such as many involved with drug interaction, cannot be crystallized and imaging would require numerous samples to bombard in order to get a full composite picture. Young's laser technique allows for millions of molecules suspended in a gaseous state to be aligned so that when bombarded with x-rays, they all diffract in the same way. The resulting images are at atomic level resolution and do not require crystallization.

"Understanding the structure of the approximately 1 million human proteins that cannot be crystallized is perhaps the most important challenge facing structural biology," Young said.

"A method for structure determination at atomic resolution without the need to crystallize would be revolutionary."

Young and her team have successfully aligned molecules using a laser, probed the aligned ensemble with x-rays and shown theoretically that the technique could be used for x-ray imaging (See E. R. Peterson et al., Applied Physics Letters 92, 094106 (2008)), but they require an proposed upgrade to the Advanced Photon Source facility located at Argonne before x-ray diffraction can be done experimentally.

Source: Argonne National Laboratory

Explore further: New insights found in black hole collisions

add to favorites email to friend print save as pdf

Related Stories

Breakthrough With Ultra-Fast Xrays

Jul 03, 2007

Electromagnetically-induced transparency, or EIT, has been known in the visible realm for quite some time. The process is used to control such characteristics as dispersion and absorption in gases, allowing the gases to become ...

Recommended for you

New insights found in black hole collisions

Mar 27, 2015

New research provides revelations about the most energetic event in the universe—the merging of two spinning, orbiting black holes into a much larger black hole.

X-rays probe LHC for cause of short circuit

Mar 27, 2015

The LHC has now transitioned from powering tests to the machine checkout phase. This phase involves the full-scale tests of all systems in preparation for beam. Early last Saturday morning, during the ramp-down, ...

Swimming algae offer insights into living fluid dynamics

Mar 27, 2015

None of us would be alive if sperm cells didn't know how to swim, or if the cilia in our lungs couldn't prevent fluid buildup. But we know very little about the dynamics of so-called "living fluids," those ...

Fluctuation X-ray scattering

Mar 26, 2015

In biology, materials science and the energy sciences, structural information provides important insights into the understanding of matter. The link between a structure and its properties can suggest new ...

Hydrodynamics approaches to granular matter

Mar 26, 2015

Sand, rocks, grains, salt or sugar are what physicists call granular media. A better understanding of granular media is important - particularly when mixed with water and air, as it forms the foundations of houses and off-shore ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

quantum_boy
not rated yet May 13, 2008
The good thing about this idea is that it could be used at 3rd generation x-ray facilities. Without this innovation, 4th generation x-ray sources (of which there are considerably fewer) would be needed.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.