title: Time-resolved structural studies of protein reaction dynamics: a smorgasbord of X-ray approaches.
abstract: Proteins undergo conformational changes during their biological function. As such, a high-resolution structure of a protein's resting conformation provides a starting point for elucidating its reaction mechanism, but provides no direct information concerning the protein's conformational dynamics. Several X-ray methods have been developed to elucidate those conformational changes that occur during a protein's reaction, including time-resolved Laue diffraction and intermediate trapping studies on three-dimensional protein crystals, and time-resolved wide-angle X-ray scattering and X-ray absorption studies on proteins in the solution phase. This review emphasizes the scope and limitations of these complementary experimental approaches when seeking to understand protein conformational dynamics. These methods are illustrated using a limited set of examples including myoglobin and haemoglobin in complex with carbon monoxide, the simple light-driven proton pump bacteriorhodopsin, and the superoxide scavenger superoxide reductase. In conclusion, likely future developments of these methods at synchrotron X-ray sources and the potential impact of emerging X-ray free-electron laser facilities are speculated upon.
authors.affiliation: Department of Chemistry, Biochemistry and Biophysics, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Westenhoff
authors.forename: Elena
authors.initials: E
authors.lastname: Nazarenko
authors.forename: Erik
authors.initials: E
authors.lastname: Malmerberg
authors.forename: Jan
authors.initials: J
authors.lastname: Davidsson
authors.forename: Gergely
authors.initials: G
authors.lastname: Katona
authors.forename: Richard
authors.initials: R
authors.lastname: Neutze
mesh_terms: D003198:Computer Simulation; D018360:Crystallography, X-Ray; D007700:Kinetics; D007834:Lasers; D008958:Models, Molecular; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D011506:Proteins