title: The frontiers of time-resolved macromolecular crystallography: movies and chirped X-ray pulses.
abstract: Three important frontiers of ultrafast time-resolved macromolecular crystallography are presented: extension of this technique to other biological systems; further developments in the elucidation of mechanism through the analysis of time-dependent movies to extract the underlying, time-independent, intermediate structures; and enhanced time resolution. The last is intimately linked with the nature of the pump-probe experiment itself, with the sources of random and, particularly, systematic experimental error, and with the factors that contribute to overall time resolution. All experiments to date have utilized the unchirped X-ray pulses that are emitted by synchrotron sources. Chirped pulses offer certain advantages for ultrafast X-ray experiments such as those based on Laue diffraction. An energy-chirped pulse maps photon energy into time; a Laue diffraction experiment maps photon energy into detector space. Hence, a Laue experiment with an energy-chirped pulse maps time into space. The proposed sub-picosecond photon source could provide an excellent source of intense, chirped hard X-rays for such experiments.
authors.affiliation: Department of Biochemistry and Molecular Biology, Institute for Biophysical Dynamics, and Consortium for Advanced Radiation Sources, The University of Chicago, 920 East 58th Street, Chicago, Illinois 60637, USA.
authors.forename: Keith
authors.initials: K
authors.lastname: Moffat
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry; D018360:Crystallography, X-Ray / Q000295:instrumentation / Q000379:methods*; D046911:Macromolecular Substances; D009211:Myoglobin / Q000737:chemistry; D020283:Photoreceptors, Microbial / Q000737:chemistry; D011506:Proteins / Q000737:chemistry; D011827:Radiation; D017356:Synchrotrons; D013997:Time Factors
chemical_list: D001426:Bacterial Proteins; D046911:Macromolecular Substances; D009211:Myoglobin; D020283:Photoreceptors, Microbial; D011506:Proteins; C050162:photoactive yellow protein, Bacteria