Techniques for Obtaining High Resolution Information about Periodic Arrays of Biological Macromolecules in the Electron Microscope

1982 ◽  
Vol 40 ◽  
pp. 68-71
Author(s):  
S. B. Hayward
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Structure Analysis ◽  
Structural Information ◽  
Probability Distributions ◽  
High Resolution Electron Microscopy ◽  
Three Dimensions ◽  
Biological Macromolecules ◽  
Periodic Arrays ◽  
High Resolution Structure

In the past six years considerable effort has been expended in EM structure analysis of periodic arrays of biological macromolecules. Although sparked by the success of the moderately high resolution structure analysis of purple membrane J most of this work has been limited in resolution to anywhere from 30 to 15 A. Although there is much to learn out to this range of resolution, especially in three dimensions, there is a wealth of structural information awaiting us beyond it. Our ultimate goal must, of course, be information in the range of 3 A, which for proteins is enough to allow us to trace the path of the polypeptide chain. In fact, much of this information is accessible by electron microscopy, providing that the periodic arrays are ordered to this extent. However, great care must be taken to optimize all aspects of microscopy and image processing in order for structural information of a resolution close to the instrumental limitation to be obtained. Following are some of the more important factors which will determine success or failure of an attempt at high resolution imaging, in this case assumed to be of an untilted specimen. While some of these factors have been known for years by workers in the field of high resolution electron microscopy, others are problems unique to imaging biological macromolecular arrays. The recent solution of some of these problems involves the use of probability distributions to describe image phases.

Atomic chemistry by HREM and image simulations?

1986 ◽  
Vol 44 ◽  
pp. 828-829
Author(s):  
J.M. Howe ◽  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Structural Information ◽  
High Resolution Electron Microscopy ◽  
Resolution Electron ◽  
Image Simulations

The technique of high-resolution electron microscopy (HREM) is invaluable to the materials scientist because it allows examination of microstructural features at levels of resolution that are unobtainable by most other methods. Although the structural information which can be determined by HREM and accompanying image simulations has been well documented in the literature, there have only been a few cases where this technique has been used to reveal the chemistry of individual columns or planes of atoms, as occur in segregated and ordered materials.

scholarly journals Rapid high-resolution structure analysis of small, biotechnologically relevant enzymes by cryo-electron microscopy

2021 ◽  
Author(s):  
Nicole Dimos ◽  
Carl P.O. Helmer ◽  
Andrea M. Chanique ◽  
Markus C. Wahl ◽  
Robert Kourist ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Structural Biology ◽  
Structure Analysis ◽  
Cryo Electron Microscopy ◽  
High Resolution Structure ◽  
Fast Development ◽  
Pharmaceutical Industries ◽  
Exquisite Specificity ◽  
Resolution Structure

Enzyme catalysis has emerged as a key technology for developing efficient, sustainable processes in the chemical, biotechnological and pharmaceutical industries. Plants provide large and diverse pools of biosynthetic enzymes that facilitate complex reactions, such as the formation of intricate terpene carbon skeletons, with exquisite specificity. High-resolution structural analysis of these enzymes is crucial to understand their mechanisms and modulate their properties by targeted engineering. Although cryo-electron microscopy (cryo-EM) has revolutionized structural biology, its applicability to high-resolution structure analysis of comparatively small enzymes is so far largely unexplored. Here, we show that cryo-EM can reveal the structures of ~120 kDa plant borneol dehydrogenases at or below 2 Å resolution, paving the way for the fast development of new biocatalysts that provide access to bioactive terpenes and terpenoids.

Direct structure analysis of advanced nanomaterials by high-resolution electron microscopy

2012 ◽  
Vol 1 (5) ◽  
pp. 389-425 ◽  
Author(s):  
Takeo Oku
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Nanostructured Materials ◽  
Structure Analysis ◽  
Incident Beam ◽  
High Resolution Electron Microscopy ◽  
Structure Model ◽  
Resolution Electron ◽  
Correction Technique ◽  
Resolution Imaging

AbstractHigh-resolution electron microscopy (HREM) analysis has contributed to the direct structure analysis of advanced nanostructured materials, of which the properties of these materials are strongly dependent on the atomic arrangements. In the present article, the direct structure analysis of nanostructured materials such as boride and oxide materials was described and the high-resolution imaging methods were applied to boron nitride nanomaterials such as nanotubes and nanoparticles. An aberration correction technique is also expected as an advanced nanostructure analysis with higher resolution. The HREM image of TlBa2Ca3Cu4O11 was taken with the incident beam parallel to the a axis together with a structure model after image processing.

Structure analysis of amorphous Pd75Si25 alloy by electron diffraction and high-resolution electron microscopy

1996 ◽  
Vol 217-218 ◽  
pp. 392-396 ◽  
Author(s):  
Mitsuhide Matsushita ◽  
Yoshibiko Hirotsu ◽  
Tadakatsu Ohkubo ◽  
Tetsuo Oikawa ◽  
Akihiro Makino
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Structure Analysis ◽  
High Resolution Electron Microscopy ◽  
Resolution Electron

High-Resolution Electron Microscopy of condensed clusters in a potassium barium oxomolybdate

1994 ◽  
Vol 52 ◽  
pp. 648-649
Author(s):  
R. Ramlau ◽  
G. L. Schimek ◽  
R. E. McCarley ◽  
A. Simon
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Structure Analysis ◽  
High Resolution Electron Microscopy ◽  
General Concept ◽  
Molybdenum Oxides ◽  
Compound K ◽  
Space Group ◽  
X Ray ◽  
Resolution Electron

The recently synthesized compound K0.19Ba3.81Mo22O34 is a representative of the ternary and quaternary reduced molybdenum oxides in which clusters built from molybdenum octahedra are arranged in layers of composition AxByMo4n+2O6n+4. The number of trans-edgesharing molybdenum octahedra in the cluster is represented by n. The general concept of cluster condensation is formulated and discussed elsewhere. For K0.19Ba3.81Mo22O34, n is equal to 5. A ternary representative, likewise with n = 5, is In6Mo22O34.By x-ray structure analysis, K0.19Ba3.81Mo22O34 proved to crystallize in space group P21/a with parameters a = 0.9908(2) nm, b = 0.9353(2) nm, c = 1.5951(3) nm, and β = 98.78(2)°. The potassium atoms were found to reside on the same sites as the barium atoms with an almost statistical distribution.We studied K0.19Ba3.81Mo22O34 by high-resolution electron microscopy (HREM). Small fragments of a crystal were investigated using a Philips CM30/ST microscope operating at 300 kV (point resolution 0.19 nm). At appropriate orientations of the crystal fragments, HREM images reveal domains of two ordered polytypes: a monoclinic and an orthorhombic one (Figs. 1 and 2).

Structure Analysis of Ni-Silicides Formed in Lateral Diffusion Couples

1984 ◽  
Vol 37 ◽  
Author(s):  
S. H. Chen ◽  
J. C. Barbour ◽  
L. R. Zheng ◽  
C. B. Carter ◽  
J. W. Mayer
Keyword(s):  
Electron Microscopy ◽  
Phase Diagram ◽  
High Resolution ◽  
Structure Analysis ◽  
Composition Range ◽  
Lateral Diffusion ◽  
High Resolution Electron Microscopy ◽  
The Other ◽  
Diffusion Couples ◽  
Resolution Electron

AbstractThe microstructures of the silicide Ni5Si2, which formed in self-supporting Ni-Si lateral-diffusion couples has been studied using high-resolution electron microscopy. Two different polymorphs (or polytypes) for Ni5Si2 have been observed. The actual composition of one polytype is confirmed to be Ni31Si12, while the other one has not yet been identified. Variations in the distribution of the two polytypes, as observed in the present study, may account for the composition range of Ni5Si2 in the Ni-Si phase diagram.

scholarly journals Simplified Approach for Preparing Graphene Oxide TEM Grids for Stained and Vitrified Biomolecules

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 643
Author(s):  
Anil Kumar ◽  
Nayanika Sengupta ◽  
Somnath Dutta
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
High Resolution ◽  
Biological Macromolecules ◽  
Contrast Transfer Function ◽  
Discharge System ◽  
Simplified Approach ◽  
Heavy Equipment ◽  
Peristaltic Pumps ◽  
High Resolution Structure

In this manuscript, we report the application of graphene oxide (GO) in the preparation of cryo-electron microscopy (cryo-EM) and transmission electron microscopy (TEM) grids. We treated GO with water and organic solvents, such as, methanol, ethanol and isopropanol separately to isolate significantly large GO monolayer flake to fabricate the grids for cryo-EM and TEM study. We implemented a simplified approach to isolate flakes of GO monolayer for constructing the TEM grids, independent of expensive heavy equipment (Langmuir–Blodgett trough, glow-discharge system, carbon-evaporator or plasma-cleaner or peristaltic pumps). We employed confocal microscopy, SEM and TEM to characterize the flake size, stability and transparency of the GO monolayer and atomic force microscopy (AFM) to probe the depth of GO coated grids. Additionally, GO grids are visualized at cryogenic condition for suitability of GO monolayer for cryo-EM study. In addition, GO-Met-H2O grids reduce the effect of preferred orientation of biological macromolecules within the amorphous ice. The power-spectrum and contrast-transfer-function unequivocally suggest that GO-Met-H2O fabricated holey grids have excellent potential for application in high-resolution structural characterization of biomolecules. Furthermore, only 200 movies and ~8000 70S ribosome particles are selected on GO-coated grids for cryo-EM reconstruction to achieve high-resolution structure.

Electron Crystallography of Phthalocyanines

1999 ◽  
Vol 03 (07) ◽  
pp. 672-678 ◽  
Author(s):  
J. R. FRYER
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Diffraction Data ◽  
Structural Information ◽  
High Resolution Electron Microscopy ◽  
Electron Diffraction Data ◽  
Electron Crystallography ◽  
Resolution Electron ◽  
Copper Phthalocyanines

It is shown that it is possible to obtain structural information from small (<100 nm) phthalocyanine crystals by using crystallographic direct phasing methods applied to electron diffraction data. This technique is both quantitative and does not suffer from the difficulties associated with high-resolution electron microscopy. Structural information has been obtained from both tetra- and octa chloro-copper phthalocyanines, and the results compared with the hydrogenated and perchloro members of the series.

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