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Posted: April 16, 2008
Scientists develop techniques for creating molecular movies
(Nanowerk News) They may never win an Oscar, but scientists at the U.S. Department of Energy's (DOE) Argonne National Laboratory have developed techniques for creating accurate movies of biological and chemical molecules, a feat only theorized up until now.
Biological and organic molecules in solution are far more complex than the standard crystalline structures of salt or metals since they are constantly moving and changing over time. These motions have not yet been seen directly, but scientists using the high-intensity X-rays at the Advanced Photon Source have measured images that are "blurred" by these motions and have used them to create more accurate movies of molecular motions.
Computer simulations are currently the only way to visualize molecular motions in solution, but researchers have not had a means to check the accuracy of these simulations for complex molecules. For the first time, scientists can see the movements first hand and compare them to their theoretical counterparts.
" The blurring that we see in our solution X-ray patterns are remarkably sensitive to the type of the molecular motion," senior chemist David Tiede said. "For the first time, we are able to test the accuracy of the simulation and change it to fit data better. Without it, we had no way of knowing how accurate the models were."
Tiede hopes an improved accuracy in molecular modeling will give insights into the structure and behavior of the molecules. Collaborators at the National Institutes of Health have used this approach to help determine structures of important biological molecules.
Tiede and his collaborators also plan to examine how a structure reacts to an outside stimulus. By using a laser to excite the atoms, he will create a movie that shows how the molecule reacts to the initial laser pulse and also how it returns to a stable condition.
"We hope to establish between'good' and'bad' molecular actors in important chemical processes like photosynthesis, solar energy and catalysts," Tiede said. "Once we see that, we can make these processes work better."
Watch molecular movies
(Click image for movie) DNA – Biological and organic molecules in solution, such as DNA, are far more complex than the standard crystalline structures of salt or metals since they are constantly moving and changing over time. These motions have not yet been seen directly, but scientists using the high intensity X-rays at the Advanced Photon Source have measured images that are “blurred” by these motions and have used them to create more accurate movies of molecular motions. (Image: ANL)
(Click image for movie) This animated gif shows the molecular structure of porphyrin changing along with a calculated X-ray scattering pattern that corresponds to the structure of a light-harvesting porphyrin array. (Image: ANL)
About Argonne National Laboratory
Argonne National Laboratory brings the world's brightest scientists and engineers together to find exciting and creative new solutions to pressing national problems in science and technology. The nation's first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America 's scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.
Funding for this research was provided by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences. The mission of the Basic Energy Sciences program—a multipurpose, scientific research effort—is to foster and support fundamental research to expand the scientific foundations for new and improved energy technologies and for understanding and mitigating the environmental impacts of energy use. The portfolio supports work in the natural sciences, emphasizing fundamental research in materials sciences, chemistry, geosciences and aspects of biosciences.
For more information, please contact Brock Cooper (630/252-5565 or email@example.com) at Argonne.