scholarly journals Structure determination from lipidic cubic phase embedded microcrystals by MicroED

2019 ◽  
Author(s):  
Lan Zhu ◽  
Guanhong Bu ◽  
Liang Jing ◽  
Dan Shi ◽  
Tamir Gonen ◽  
...  
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
Structure Determination ◽  
Model System ◽  
Proteinase K ◽  
Electron Diffraction Data ◽  
Cubic Phase ◽  
High Quality ◽  
Small Crystals ◽  
Lipidic Cubic Phase

AbstractThe lipidic cubic phase (LCP) technique has proved to facilitate the growth of high-quality crystals that are otherwise difficult to grow by other methods. Because crystals grown in LCP can be limited in size, improved techniques for structure determination from these small crystals are important. Microcrystal electron diffraction (MicroED) is a technique that uses a cryo-TEM to collect electron diffraction data and determine high-resolution structures from very thin micro and nanocrystals. In this work, we have used modified LCP and MicroED protocols to analyze crystals embedded in LCP. Proteinase K in LCP was used as a model system, and several LCP sample preparation strategies were tested. Among these, treatment with 2-Methyl-2,4-pentanediol (MPD) and lipase were both able to reduce the viscosity of the LCP and produce quality cryo-EM grids with well-diffracting crystals. These results set the stage for the use of MicroED to analyze other microcrystalline samples grown in LCP.

scholarly journals MicroED: a versatile cryoEM method for structure determination

2018 ◽  
Vol 2 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Brent L. Nannenga ◽  
Tamir Gonen
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Electron Diffraction ◽  
Structure Determination ◽  
Materials Science ◽  
Electron Diffraction Data ◽  
Determination Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Micro-electron diffraction, or MicroED, is a structure determination method that uses a cryo-transmission electron microscope to collect electron diffraction data from nanocrystals. This technique has been successfully used to determine the high-resolution structures of many targets from crystals orders of magnitude smaller than what is needed for X-ray diffraction experiments. In this review, we will describe the MicroED method and recent structures that have been determined. Additionally, applications of electron diffraction to the fields of small molecule crystallography and materials science will be discussed.

scholarly journals A Workflow for Protein Structure Determination from Thin Crystal Lamella by Micro-Electron Diffraction

2020 ◽  
Author(s):  
Emma V. Beale ◽  
David G. Waterman ◽  
Corey Hecksel ◽  
Jason van Rooyen ◽  
James B. Gilchrist ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Data Processing ◽  
Structure Determination ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Protein Structure Determination ◽  
Proteinase K ◽  
Protein Crystal ◽  
Electron Diffraction Data ◽  
X Ray Crystallography

AbstractMicro-Electron Diffraction (MicroED) has recently emerged as a powerful method for the analysis of biological structures at atomic resolution. This technique has been largely limited to protein nanocrystals which grow either as needles or plates measuring only a few hundred nanometres in thickness. Furthermore, traditional microED data processing uses established X-ray crystallography software that is not optimised for handling compound effects that are unique to electron diffraction data. Here, we present an integrated workflow for microED, from sample preparation by cryo-focused ion beam milling, through data collection with a standard Ceta-D detector, to data processing using the DIALS software suite, thus enabling routine atomic structure determination of protein crystals of any size and shape using microED. We demonstrate the effectiveness of the workflow by determining the structure of proteinase K to 2.0 Å resolution and show the advantage of using protein crystal lamellae over nanocrystals.

Crystal Structure Determination of Glycerol-Containing Lipids from Electron Diffraction Data. Use of Analog Compounds Based upon Configurational Isomers of Cyclopentane-1, 2, 3-TRIOL

1977 ◽  
Vol 35 ◽  
pp. 24-25
Author(s):  
Douglas L. Dorset ◽  
Anthony J. Hancock
Keyword(s):  
Crystal Structure ◽  
Electron Diffraction ◽  
Diffraction Data ◽  
Structure Determination ◽  
Crystal Surface ◽  
Coherent Scattering ◽  
Crystal Structure Determination ◽  
Electron Diffraction Data ◽  
Polar Group ◽  
Axis Orientation

Lipids containing long polymethylene chains were among the first compounds subjected to electron diffraction structure analysis. It was only recently realized, however, that various distortions of thin lipid microcrystal plates, e.g. bends, polar group and methyl end plane disorders, etc. (1-3), restrict coherent scattering to the methylene subcell alone, particularly if undistorted molecular layers have well-defined end planes. Thus, ab initio crystal structure determination on a given single uncharacterized natural lipid using electron diffraction data can only hope to identify the subcell packing and the chain axis orientation with respect to the crystal surface. In lipids based on glycerol, for example, conformations of long chains and polar groups about the C-C bonds of this moiety still would remain unknown.One possible means of surmounting this difficulty is to investigate structural analogs of the material of interest in conjunction with the natural compound itself. Suitable analogs to the glycerol lipids are compounds based on the three configurational isomers of cyclopentane-1,2,3-triol shown in Fig. 1, in which three rotameric forms of the natural glycerol derivatives are fixed by the ring structure (4-7).

scholarly journals Procedure and Computer Programs for the Structure Determination of Gaseous Molecules from Electron Diffraction Data.

1969 ◽  
Vol 23 ◽  
pp. 3224-3234 ◽  
Author(s):  
B. Andersen ◽  
H. M. Seip ◽  
T. G. Strand ◽  
R. Stølevik ◽  
Gunner Borch ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Diffraction Data ◽  
Structure Determination ◽  
Computer Programs ◽  
Electron Diffraction Data

High quality electron diffraction data by precession

2009 ◽  
pp. 767-768
Author(s):  
Sven Hovmöller ◽  
Daliang Zhang ◽  
Junliang Sun ◽  
Xiaodong Zou ◽  
Peter Oleynikov
Keyword(s):  
Electron Diffraction ◽  
Diffraction Data ◽  
Electron Diffraction Data ◽  
High Quality

scholarly journals Femtosecond crystallography of membrane proteins in the lipidic cubic phase

2014 ◽  
Vol 369 (1647) ◽  
pp. 20130314 ◽  
Author(s):  
Wei Liu ◽  
Daniel Wacker ◽  
Chong Wang ◽  
Enrique Abola ◽  
Vadim Cherezov
Keyword(s):  
Membrane Proteins ◽  
Structure Determination ◽  
Cubic Phase ◽  
Technological Advances ◽  
Lipidic Cubic Phase ◽  
High Resolution Structure ◽  
Effects Of Radiation ◽  
G Protein Coupled ◽  
Serial Femtosecond Crystallography

Despite recent technological advances in heterologous expression, stabilization and crystallization of membrane proteins (MPs), their structural studies remain difficult and require new transformative approaches. During the past two years, crystallization in lipidic cubic phase (LCP) has started gaining a widespread acceptance, owing to the spectacular success in high-resolution structure determination of G protein-coupled receptors (GPCRs) and to the introduction of commercial instrumentation, tools and protocols. The recent appearance of X-ray free-electron lasers (XFELs) has enabled structure determination from substantially smaller crystals than previously possible with minimal effects of radiation damage, offering new exciting opportunities in structural biology. The unique properties of LCP material have been exploited to develop special protocols and devices that have established a new method of serial femtosecond crystallography of MPs in LCP (LCP-SFX). In this method, microcrystals are generated in LCP and streamed continuously inside the same media across the intersection with a pulsed XFEL beam at a flow rate that can be adjusted to minimize sample consumption. Pioneering studies that yielded the first room temperature GPCR structures, using a few hundred micrograms of purified protein, validate the LCP-SFX approach and make it attractive for structure determination of difficult-to-crystallize MPs and their complexes with interacting partners. Together with the potential of femtosecond data acquisition to interrogate unstable intermediate functional states of MPs, LCP-SFX holds promise to advance our understanding of this biomedically important class of proteins.

STRUCTURE DETERMINATION OF THE Ge(111)-(3×1)Ag SURFACE RECONSTRUCTION

1999 ◽  
Vol 06 (06) ◽  
pp. 1061-1065 ◽  
Author(s):  
D. GROZEA ◽  
E. BENGU ◽  
C. COLLAZO-DAVILA ◽  
L. D. MARKS
Keyword(s):  
Electron Diffraction ◽  
Surface Reconstruction ◽  
Diffraction Data ◽  
Structure Determination ◽  
Heavy Atom ◽  
Direct Methods ◽  
Electron Diffraction Data ◽  
Transmission Electron ◽  
First Time

For the first time, during the investigation of the Ag submonolayer on the Ge(111) system, large, independent domains of the Ge (111)-(3×1) Ag phase were imaged and investigated. Previous studies have reported it only as small insets between Ge (111)-(4×4) Ag and Ge (111)- c (2×8) domains. The transmission electron diffraction data were analyzed using a Direct Methods approach and "heavy-atom holography," with the result of an atomic model of the structure similar to that of Ge (111)-(3×1) Ag .

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