|
Argonne scientists use lasers to align molecules
May 14, 2008Protein 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 (DOE) 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.
DOE/Argonne National Laboratory
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.
DOE/Argonne National Laboratory
X-ray Diffraction News and Current X-ray Diffraction Events RSSSuperconductors get a boost from pressure
Superconductors can convey more than 150 times more electricity than copper wires because they don't restrict electron movement, the essence of electricity.
Synchrotron light unveils oil in ancient Buddhist paintings from Bamiyan
The world was in shock when in 2001 the Talibans destroyed two ancient colossal Buddha statues in the Afghan region of Bamiyan.
Scientists solve structure of gene regulator that plays key role in cancer
Scientists at The Wistar Institute have collaborated on a major advance in understanding a gene regulator that contributes to some of the deadliest cancers in humans. The culmination of 10 years' work, their research paves the way for the development of new cancer therapies.
Structure of important neurotransmitter regulator determined
Researchers from Virginia Tech and the Brookhaven National Laboratory have solved the structure of an enzyme that is critical in the regulation of the neurotransmitter system in the human brain.
Hybrid semiconductors show zero thermal expansion; could lead to hardier electronics and optoelectronics
The fan in your computer is there to keep the microprocessor chip from heating to the point where its component materials start to expand, inducing cracks that interrupt the flow of electricity - and not incidentally, ruin the chip.
Researchers outline structure of largest nonvirus particle ever crystallized
Researchers at UCLA's California NanoSystems Institute, the David Geffen School of Medicine at UCLA and the Howard Hughes Medical Institute have modeled the structure of the largest cellular particle ever crystallized, suggesting ways to engineer the particles for drug delivery.
Argonne scientists use unique diamond anvils to view oxide glass structures under pressure
Researchers at the U.S. Department of Energy's Argonne National Laboratory have used a uniquely-constructed perforated diamond cell to investigate oxide glass structures at high pressures in unprecedented detail.
First high-res 3D structures of mammalian HSP90 protein solved
Dr. Dan Gewirth, Hauptman-Woodward senior research scientist, has just solved the structure of the first mammalian GRP94 protein implicated in immune diseases such as sepsis, AIDS and certain cancers.
Researchers locate mantle's spin transition zone, leading to clues about Earth's structure
Researchers have located the spin transition zone of iron in Earth's lower mantle, a discovery which has profound geophysical implications.
Greenhouse gas burial
Deep coal seams that are not commercially viable for coal production could be used for permanent underground storage of carbon dioxide (CO2) generated by human activities, thus avoiding atmospheric release.
More X-ray Diffraction News Articles
 | Outline of Crystallography for Biologists by David Blow |
 | X-Ray Diffraction by B. E. Warren |
 | Crystal Structure Determination by Werner Massa |
 | Elements of X-Ray Diffraction (3rd Edition) by B.D. Cullity, S.R. Stock |
 | X-Ray Diffraction: In Crystals, Imperfect Crystals, and Amorphous Bodies by A. Guinier |
 | The Basics of Crystallography and Diffraction (International Union of Crystallography Texts on Crystallography, 5) by Christopher Hammond |
 | X-Ray Diffraction and the Identification and Analysis of Clay Minerals by Duane M. Moore, Robert C. Reynolds |
 | Transmission Electron Microscopy: Physics of Image Formation (Springer Series in Optical Sciences) by Ludwig Reimer, Helmut Kohl |
| The Optical Principles of the Diffraction of X-Rays by R.W. James | |
| Elements of X-ray Diffraction (Addison-Wesley Series in Metallurgy and Materials) by B. D. Cullity |
| © 2008 BrightSurf.com |