Electron crystallography

Résumé

Electron crystallography is a method to determine the arrangement of atoms in solids using a transmission electron microscope (TEM). It can involve the use of high-resolution transmission electron microscopy images, electron diffraction patterns including convergent-beam electron diffraction or combinations of these. It has been successful in determining some bulk structures, and also surface structures. Two related methods are low-energy electron diffraction which has solved the structure of many surfaces, and reflection high-energy electron diffraction which is used to monitor surfaces often during growth. Comparison with X-ray crystallography It can complement X-ray crystallography for studies of very small crystals (

Source officielle

https://en.wikipedia.org/wiki/Electron_crystallography

À propos de ce résultat

Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.

Publications associées (37)

Publications associées

Chargement

Personnes associées (1)

Personnes associées

Chargement

Unités associées (1)

Unités associées

Chargement

Concepts associés (11)

Concepts associés

Chargement

Cours associés (4)

This intensive course is intended for researchers who envisage to use scanning electron microscopy techniques for their research or who want to understand how to interpret SEM images and analytical results presented in scientific publications.

Introduction to geometrical and wave optics for understanding the principles of optical microscopes, their advantages and limitations. Describing the basic microscopy components and the commonly used biomicrocopy methods such as widefield and fluorescence.

This lecture gives an introduction to Solid State Physics, namely to their crystal and electronic structure, their magnetic properties, as well as to their thermal and electric conductance. The level is that of the book by Ashcroft & Mermin. The lecture is for Physics Students in their 3rd year

Afficher plus

Cours associés

Chargement

Séances de cours associées (4)

Séances de cours associées

Chargement

The 4.5 angstrom structure of human AQP2

Andreas Engel, Henning Paul-Julius Stahlberg

Located in the principal cells of the collecting duct, aquaporin-2 (AQP2) is responsible for the regulated water reabsorbtion in the kidney and is indispensable for the maintenance of body water balance. Disregulation or malfunctioning of AQP2 can lead to severe diseases such as nephrogenic diabetes insipidus, congestive heart failure, liver cirrhosis and preeclampsia. Here we present the crystallization of recombinantly expressed human AQP2 into two-dimensional protein-lipid arrays and their structural characterization by atomic force microscopy and electron crystallography. These crystals are double-layered sheets that have a diameter of up to 30 mu m, diffract to 3 angstrom(-1) and are stacked by contacts between their cytosolic surfaces. The structure determined to 4.5 angstrom resolution in the plane of the membrane reveals the typical aquaporin fold but also a particular structure between the stacked layers that is likely to be related to the cytosolic N and C termini. (c) 2005 Elsevier Ltd. All rights reserved.

Elsevier BV2005

Chargement

Progress in the analysis of membrane protein structure and function

Andreas Engel, Henning Paul-Julius Stahlberg

Structural information on membrane proteins is sparse, yet they represent an important class of proteins that is encoded by about 30% of all genes. Progress has primarily been achieved with bacterial proteins, but efforts to solve the structure of eukaryotic membrane proteins are also increasing. Most of the structures currently available have been obtained by exploiting the power of X-ray crystallography. Recent results, however, have demonstrated the accuracy of electron crystallography and the imaging power of the atomic force microscope. These instruments allow membrane proteins to be studied while embedded in the bi-layer, and thus in a functional state. The low signal-to-noise ratio of cryo-electron microscopy is overcome by crystallizing membrane proteins in a two-dimensional protein-lipid membrane, allowing its atomic structure to be determined. In contrast, the high signal-to-noise ratio of atomic force microscopy allows individual protein surfaces to be imaged at subnanometer resolution, and their conformational states to be sampled. This review summarizes the steps in membrane protein structure determination and illuminates recent progress. (C) 2002 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.

Wiley-Blackwell2002

Chargement

Two-dimensional crystals: a powerful approach to assess structure, function and dynamics of membrane proteins

Andreas Engel, Henning Paul-Julius Stahlberg

Electron crystallography and atomic force microscopy allow the study of two-dimensional membrane protein crystals. While electron crystallography provides atomic scale three-dimensional density maps, atomic force microscopy gives insight into the surface structure and dynamics at sub-nanometer resolution. Importantly, the membrane protein studied is in its native environment and its function can be assessed directly. The approach allows both the atomic structure of the membrane protein and the dynamics of its surface to be analyzed. In this way, the function-related conformational changes can be assessed, thus providing a detailed insight on the molecular mechanisms of essential biological processes. (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.

Wiley-Blackwell2001

Chargement