Quick-change molecules caught in the act

By Steve McGregorMay 1, 2010

The chemistry of life happens so fast that a millionth of a second is largely invisible to science and in that time, molecules change in ways we cannot see. Now there is a way of looking at molecules in solution—as they are in life—that shows both the big-picture shape and smaller-scale details of a molecule in one glance, with each glimpse being captured in one hundred trillionths of a second.

With this technique, new chemical landscapes are now open to study. Working at the BioCARS beamline 14-ID at the U.S. Department of Energy’s Advanced Photon Source at Argonne National Laboratory, researchers from the National Institutes of Health and the University of Chicago have combined simultaneous small-angle and wide-angle x-ray scattering (SAXS and WAXS) with an ultrafast laser to observe the dynamics of a protein in solution with 100-picosecond time resolution and 2.5-Å spatial resolution.

Because this technique allows researchers to study molecules in solution rather than in single crystals, to collect SAXS and WAXS data simultaneously, to probe at the picosecond time scale, and to use light as a trigger, it is now possible to ask entirely new questions about a wide range of chemical and biological systems.

Citation information: Hyun Sun Cho et al., “Protein Structural Dynamics in Solution Unveiled via 100-ps Time-resolved X-ray Scattering,” PNAS, 107 (16), 7281 (20 April 2010).