ジャーナル: IUCrJ / 年: 2019 タイトル: Nanobeam precession-assisted 3D electron diffraction reveals a new polymorph of hen egg-white lysozyme. 著者: Arianna Lanza / Eleonora Margheritis / Enrico Mugnaioli / Valentina Cappello / Gianpiero Garau / Mauro Gemmi / 要旨: Recent advances in 3D electron diffraction have allowed the structure determination of several model proteins from submicrometric crystals, the unit-cell parameters and structures of which could be ...Recent advances in 3D electron diffraction have allowed the structure determination of several model proteins from submicrometric crystals, the unit-cell parameters and structures of which could be immediately validated by known models previously obtained by X-ray crystallography. Here, the first new protein structure determined by 3D electron diffraction data is presented: a previously unobserved polymorph of hen egg-white lysozyme. This form, with unit-cell parameters = 31.9, = 54.4, = 71.8 Å, β = 98.8°, grows as needle-shaped submicrometric crystals simply by vapor diffusion starting from previously reported crystallization conditions. Remarkably, the data were collected using a low-dose stepwise experimental setup consisting of a precession-assisted nanobeam of ∼150 nm, which has never previously been applied for solving protein structures. The crystal structure was additionally validated using X-ray synchrotron-radiation sources by both powder diffraction and single-crystal micro-diffraction. 3D electron diffraction can be used for the structural characterization of submicrometric macromolecular crystals and is able to identify novel protein polymorphs that are hardly visible in conventional X-ray diffraction experiments. Additionally, the analysis, which was performed on both nanocrystals and microcrystals from the same crystallization drop, suggests that an integrated view from 3D electron diffraction and X-ray microfocus diffraction can be applied to obtain insights into the molecular dynamics during protein crystal growth.
解像度: 2.6→31.33 Å / Cor.coef. Fo:Fc: 0.915 / Cor.coef. Fo:Fc free: 0.847 / SU B: 14.047 / SU ML: 0.293 / 交差検証法: THROUGHOUT / ESU R Free: 0.469 / 詳細: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS