title: Structure-factor analysis of femtosecond microdiffraction patterns from protein nanocrystals.
abstract: A complete set of structure factors has been extracted from hundreds of thousands of femtosecond single-shot X-ray microdiffraction patterns taken from randomly oriented nanocrystals. The method of Monte Carlo integration over crystallite size and orientation was applied to experimental data from Photosystem I nanocrystals. This arrives at structure factors from many partial reflections without prior knowledge of the particle-size distribution. The data were collected at the Linac Coherent Light Source (the first hard-X-ray laser user facility), to which was fitted a hydrated protein nanocrystal injector jet, according to the method of serial crystallography. The data are single 'still' diffraction snapshots, each from a different nanocrystal with sizes ranging between 100 nm and 2 µm, so the angular width of Bragg peaks was dominated by crystal-size effects. These results were compared with single-crystal data recorded from large crystals of Photosystem I at the Advanced Light Source and the quality of the data was found to be similar. The implications for improving the efficiency of data collection by allowing the use of very small crystals, for radiation-damage reduction and for time-resolved diffraction studies at room temperature are discussed.
authors.affiliation: Department of Physics, Arizona State University, Tempe, Arizona 85287, USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Kirian
authors.forename: Thomas A
authors.initials: TA
authors.lastname: White
authors.forename: James M
authors.initials: JM
authors.lastname: Holton
authors.forename: Henry N
authors.initials: HN
authors.lastname: Chapman
authors.forename: Petra
authors.initials: P
authors.lastname: Fromme
authors.forename: Anton
authors.initials: A
authors.lastname: Barty
authors.forename: Lukas
authors.initials: L
authors.lastname: Lomb
authors.forename: Andrew
authors.initials: A
authors.lastname: Aquila
authors.forename: Filipe R N C
authors.initials: FR
authors.lastname: Maia
authors.forename: Andrew V
authors.initials: AV
authors.lastname: Martin
authors.forename: Raimund
authors.initials: R
authors.lastname: Fromme
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Wang
authors.forename: Mark S
authors.initials: MS
authors.lastname: Hunter
authors.forename: Kevin E
authors.initials: KE
authors.lastname: Schmidt
authors.forename: John C H
authors.initials: JC
authors.lastname: Spence
mesh_terms: D018360:Crystallography, X-Ray; D005163:Factor Analysis, Statistical; D007834:Lasers; D053758:Nanoparticles / Q000737:chemistry*; D010315:Particle Accelerators; D011506:Proteins / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D011506:Proteins