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Improving the accuracy and resolution of neutron crystallographic data by three‐dimensional profile fitting of Bragg peaks in reciprocal space
Author(s) -
Sullivan Brendan,
Archibald Rick,
Langan Patricia S.,
Dobbek Holger,
Bommer Martin,
McFeeters Robert L.,
Coates Leighton,
Wang Xiaoping,
Gallmeier Franz,
Carpenter John M.,
Lynch Vickie,
Langan Paul
Publication year - 2018
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.374
H-Index - 138
ISSN - 2059-7983
DOI - 10.1107/s2059798318013347
Subject(s) - reciprocal lattice , neutron , neutron diffraction , neutron scattering , resolution (logic) , computational physics , neutron reflectometry , physics , crystallography , diffraction , materials science , small angle neutron scattering , optics , chemistry , nuclear physics , computer science , artificial intelligence
Neutron crystallography is a powerful technique for directly visualizing the locations of H atoms in biological macromolecules. This information has provided key new insights into enzyme mechanisms, ligand binding and hydration. However, despite the importance of this information, the application of neutron crystallography in biology has been limited by the relatively low flux of available neutron beams and the large incoherent neutron scattering from hydrogen, both of which contribute to weak diffraction data with relatively low signal‐to‐background ratios. A method has been developed to fit weak data based on three‐dimensional profile fitting of Bragg peaks in reciprocal space by an Ikeda–Carpenter function with a bivariate Gaussian. When applied to data collected from three different proteins, three‐dimensional profile fitting yields intensities with higher correlation coefficients (CC 1/2 ) at high resolutions, decreased R free factors, extended resolutions and improved nuclear density maps. Importantly, additional features are revealed in nuclear density maps that may provide additional scientific information. These results suggest that three‐dimensional profile fitting will help to extend the capabilities of neutron macromolecular crystallography.