scholarly journals Structure and Dynamics of Macromolecular Assemblies from Electron Microscopy Maps

10.5772/62085 ◽  
2016 ◽  
Author(s):  
Xiongwu Wu ◽  
Bernard R. Brooks
Keyword(s):  
Electron Microscopy ◽  
Macromolecular Assemblies ◽  
Structure And Dynamics

scholarly journals Ahmed Hassan Zewail. 26 February 1946—2 August 2016

2019 ◽  
Vol 68 ◽  
pp. 431-453
Author(s):  
John Meurig Thomas
Keyword(s):  
Electron Microscopy ◽  
Gas Phase ◽  
Ultrafast Lasers ◽  
Atomic Level ◽  
Women In Science ◽  
President Obama ◽  
Structure And Dynamics ◽  
Transmission Electron ◽  
The Individual ◽  
Gas Phase Electron Diffraction

Ahmed Zewail will forever be remembered for three main reasons: first, he was the individual who first demonstrated that the structure and dynamics of atoms in the transition state of chemical reactions could be determined through the judicious use of ultrafast lasers, in a field that he pioneered, for which he coined, called femtochemistry; second, he transformed both gas phase electron diffraction and transmission electron microscopy by improving their temporal resolution some 10 orders of magnitude, while simultaneously retaining the spatial resolution of electron microscopy at the atomic level; and third, he was the first US Science Envoy to the Middle East (appointed by President Obama). To all who knew him, he was a warm-hearted, life-enhancing person endowed with exceptional technical virtuosity as an experimentalist and a profound thinker, whose prodigality of output was also exceptional. He exhibited remarkable skills as an enterprising fundraiser in his determination to establish the Zewail City of Science and Technology on the outskirts of his beloved Cairo. He also influenced greatly the L'Oréal–UNESCO scheme for awarding prizes to women in science.

scholarly journals Improved metrics for comparing structures of macromolecular assemblies determined by 3D electron-microscopy

2017 ◽  
Vol 199 (1) ◽  
pp. 12-26 ◽  
Author(s):  
Agnel Praveen Joseph ◽  
Ingvar Lagerstedt ◽  
Ardan Patwardhan ◽  
Maya Topf ◽  
Martyn Winn
Keyword(s):  
Electron Microscopy ◽  
Macromolecular Assemblies ◽  
3D Electron Microscopy ◽  
3D Electron

Frontiers in Cryo Electron Microscopy of Complex Macromolecular Assemblies

2019 ◽  
Vol 21 (1) ◽  
pp. 395-415 ◽  
Author(s):  
Jana Ognjenović ◽  
Reinhard Grisshammer ◽  
Sriram Subramaniam
Keyword(s):  
Electron Microscopy ◽  
Cell Biology ◽  
Electron Tomography ◽  
Protein Complexes ◽  
Specimen Preparation ◽  
Macromolecular Assemblies ◽  
Cryo Electron Microscopy ◽  
G Protein Coupled ◽  
Improved Methods

In recent years, cryo electron microscopy (cryo-EM) technology has been transformed with the development of better instrumentation, direct electron detectors, improved methods for specimen preparation, and improved software for data analysis. Analyses using single-particle cryo-EM methods have enabled determination of structures of proteins with sizes smaller than 100 kDa and resolutions of ∼2 Å in some cases. The use of electron tomography combined with subvolume averaging is beginning to allow the visualization of macromolecular complexes in their native environment in unprecedented detail. As a result of these advances, solutions to many intractable challenges in structural and cell biology, such as analysis of highly dynamic soluble and membrane-embedded protein complexes or partially ordered protein aggregates, are now within reach. Recent reports of structural studies of G protein–coupled receptors, spliceosomes, and fibrillar specimens illustrate the progress that has been made using cryo-EM methods, and are the main focus of this review.

Protein Characterization by Low-Angle, Rotary-Replication Electron Microscopy

2000 ◽  
Vol 6 (S2) ◽  
pp. 994-995
Author(s):  
S. Samuelsson
Keyword(s):  
Electron Microscopy ◽  
Heavy Metals ◽  
Freeze Fracture ◽  
Accurate Method ◽  
Protein Characterization ◽  
Wild Type ◽  
Macromolecular Assemblies ◽  
Transmission Electron ◽  
Excellent Method ◽  
Atomically Flat

There are several established strategies for visualizing proteins by transmission electron microscopy (TEM). These include negative staining, cryo-TEM, glycerol-spray/rotary-replication, mica-flake/freeze-fracture. Of these, low-angle, rotary-replication of proteins dried out of glycerol has proven to be a reliable and accurate method for studying surface topologies of macromolecular assemblies and particles. We have characterized many proteins, both chimeras and wild type; methods, caveats and the surface structure of a couple examples are described here.The technique of using heavy metals to cast replicas of proteins and particles has been around for decades (metal replication of proteins was first described in 1956) and continues to provide an excellent method for evaluating protein topology. The success of this method is based on the physical properties of protein in contact with freshly cleaved mica, glycerol and atomic platinum. Mica is easily split and atomically flat making it an excellent substrate.

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