High-Resolution Electron Diffraction of Hydrated Protein Crystals at Room Temperature

作者：Sergi Plana‐Ruiz, Alejandro Gómez-Pérez, Monika Budayova-Spano, Daniel L. Foley, Joaquim Portillo-Serra, E.F. Rauch, Evangelos Grivas, Dominique Housset, Partha Pratim Das, Mitra L. Taheri, Stavros Nicolopoulos, Wai Li Ling · 发表于：ACS Nano · 年份：2023 · DOI：10.1021/acsnano.3c05378 · 被引用次数：9 · 研究领域：Enzyme Structure and Function、Advanced Electron Microscopy Techniques and Applications、Ion-surface interactions and analysis

High Resolution Image Download MS PowerPoint Slide Structural characterization is crucial to understanding protein function. Compared with X-ray diffraction methods, electron crystallography can be performed on nanometer-sized crystals and can provide additional information from the resulting Coulomb potential map. Whereas electron crystallography has successfully resolved three-dimensional structures of vitrified protein crystals, its widespread use as a structural biology tool has been limited. One main reason is the fragility of such crystals. Protein crystals can be easily damaged by mechanical stress, change in temperature, or buffer conditions as well as by electron irradiation. This work demonstrates a methodology to preserve these nanocrystals in their natural environment at room temperature for electron diffraction experiments as an alternative to existing cryogenic techniques. Lysozyme crystals in their crystallization solution are hermetically sealed via graphene-coated grids, and their radiation damage is minimized by employing a low-dose data collection strategy in combination with a hybrid-pixel direct electron detector. Diffraction patterns with reflections of up to 3 Å are obtained and successfully indexed using a template-matching algorithm. These results demonstrate the feasibility of in situ protein electron diffraction. The method described will also be applicable to structural studies of hydrated nanocrystals important in many research and technological d...