title: Imaging protein three-dimensional nanocrystals with cryo-EM.
abstract: Flash-cooled three-dimensional crystals of the small protein lysozyme with a thickness of the order of 100 nm were imaged by 300 kV cryo-EM on a Falcon direct electron detector. The images were taken close to focus and to the eye appeared devoid of contrast. Fourier transforms of the images revealed the reciprocal lattice up to 3 Å resolution in favourable cases and up to 4 Å resolution for about half the crystals. The reciprocal-lattice spots showed structure, indicating that the ordering of the crystals was not uniform. Data processing revealed details at higher than 2 Å resolution and indicated the presence of multiple mosaic blocks within the crystal which could be separately processed. The prospects for full three-dimensional structure determination by electron imaging of protein three-dimensional nanocrystals are discussed.
authors: Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors: Igor
authors: I
authors: Nederlof
authors: Yao Wang
authors: YW
authors: Li
authors: Marin
authors: M
authors: van Heel
authors: Jan Pieter
authors: JP
authors: Abrahams
mesh_terms: D020285:Cryoelectron Microscopy / Q000379:methods*; D005583:Fourier Analysis; D021621:Imaging, Three-Dimensional / Q000379:methods*; D009113:Muramidase / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D011506:Proteins / Q000032:analysis / Q000737:chemistry*
chemical_list: D011506:Proteins; D009113:Muramidase
keywords: electron microscopy; protein nanocrystals