Characteristic feature on structure analyzed by high-resolution electron crystallography

1995 ◽  
Vol 53 ◽  
pp. 834-835
Author(s):  
Y. Fujiyoshi ◽  
K. Mitsuoka ◽  
T. Hirai ◽  
K. Murata ◽  
A. Miyazawa ◽  
...  
Keyword(s):  
Amino Acid ◽  
High Resolution ◽  
Characteristic Feature ◽  
Proton Pump ◽  
Ccd Camera ◽  
Electron Crystallography ◽  
Embedding Technique ◽  
Resolution Electron ◽  
Ph Conditions ◽  
Diffraction Patterns

The structure of bacteriorhodopsin (bR), which was already analyzed by Henderson et al., is studied by our new electron cryo-microscope equipped with Field Emission Gun (FEG) and Slow Scan CCD camera (SSCCD), because our system together with ice embedding technique enable us to solve the structure of bR at various pH conditions between pH 4.0 and 10.0. Ionization of amino acid is naturally closely related to the translocation of proton and then the function of the proton pump of bR. Therefore, observation of translocation of proton in bR is very important, if possible. Both ice embedding and high resolution techniques are essential to achieve this intention. Therefore, we intended to develop an electron cryo-microscope fit to these techniques and recently we had succeeded it.We collected whole sets of diffraction patterns for bR up to 70 degree tilt at pH 5.5 by using SSCCD, and merged these data of 300 diffraction patterns.

Application of a slow-scan CCD camera in protein electron crystallography at 400 KV

1995 ◽  
Vol 53 ◽  
pp. 8-9
Author(s):  
Jaap Brink ◽  
Michael B. Sherman ◽  
Wah Chiu
Keyword(s):  
High Resolution ◽  
Fiber Optics ◽  
Electronic Device ◽  
Ccd Camera ◽  
Photographic Film ◽  
Electron Crystallography ◽  
Camera Model ◽  
Electron Dose ◽  
Voltage Electron ◽  
Diffraction Patterns

In protein electron crystallography, high resolution amplitudes and phases are required for a 3D reconstruction of a protein in which one can trace the Cα-backbone. Recording of these amplitudes and phases has so far been done on photographic film. In principle they can be obtained with higher fidelity using an electronic device, such as a slow-scan charge-coupled device (CCD) camera. We use a 1024 × 1024 Gatan CCD camera (model 679) attached to a JEOL 4000EX intermediate voltage electron cryo-microscope. The camera has a 20-30 μm thin P43 phosphor scintillator and an extra set of fiber optics, that reduces the number of x-ray pixels in acquired frames. In this abstract, we will focus on several issues related to the CCD camera in obtaining high resolution diffraction patterns and images from thin protein crystals.To obtain electron diffraction patterns with sufficient statistical definition, one needs to use an adequate electron dose. However, at exposures well above 0.25 e/Å2, the pattern will suffer from blooming due to the central beam.

Quantitative analysis of low-dose high-resolution images and diffraction patterns from zeolites using a slow-scan CCD camera

1993 ◽  
Vol 51 ◽  
pp. 670-671
Author(s):  
M. Pan ◽  
P.A. Crozier
Keyword(s):  
High Resolution ◽  
Molecular Sieves ◽  
Structural Damage ◽  
Low Dose ◽  
Signal To Noise Ratio ◽  
Ccd Camera ◽  
Real Space ◽  
High Signal ◽  
Resolution Electron ◽  
Diffraction Patterns

Zeolites are an important class of low-density aluminosilicates framework structures with applications to the field of catalysis and molecular sieves. In order to understand die origin of die unique properties of these materials and hence optimize their performance, it is essential to have a detailed description of their structures. Zeolite structure is often described in terms of the secondary building unit (SBU) which is a specific configuration of the SiO4 tetrahedrons. Structure determination of zeolites is then reduced to determine the types of SB Us and their connectivities when forming the 3-D framework structure.It has been recognized that zeolites undergo rapid structural damage under electron beam irradiation. The use of a slow-scan CCD camera to record low-dose high resolution electron microscope (HREM) images from zeolites with the combination with real-space averaging techniques has been shown to be successful in obtaining the averaged unit cell with high signal-to-noise ratio (SNR).

3-D diffraction intensities of the crotoxin complex crystal

1986 ◽  
Vol 44 ◽  
pp. 162-163
Author(s):  
B.V.V. Prasad ◽  
L.L. Degn ◽  
T.-W. Jeng ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Intensity Data ◽  
Electron Crystallography ◽  
Data Set ◽  
Crotalus Durissus Terrificus ◽  
Cold Stage ◽  
Resolution Electron ◽  
Diffraction Patterns ◽  
Crotalus Durissus ◽  
Complex Crystal

The crotoxin complex, a neurotoxin from the venom of the Brazilian rattlesnake, Crotalus durissus terrificus, forms thin crystals suitable for high resolution electron crystallography. These crystals grow to variable completions of the unit cell, making it difficult to merge the intensity data from different crystals. This difficulty is overcome by collecting as many electron diffraction patterns (EDP) as possible from a single crystal tilted from +60° to -60°. Several series of approximately twenty EDP's were collected using a Philips 400 equipped with a cold stage at MRC, Cambridge in Dr. R. Henderson's laboratory. We report here our progress in synthesizing a 3-D intensity data set from these series.

Light Optical Diffraction Studies of Macromolecular Ultrastructure

1970 ◽  
Vol 28 ◽  
pp. 258-259
Author(s):  
Glen B. Haydon
Keyword(s):  
High Resolution ◽  
Diffraction Analysis ◽  
Diffraction Pattern ◽  
Electron Micrographs ◽  
Optical Diffraction ◽  
Electron Micrograph ◽  
Its Analysis ◽  
Resolution Electron ◽  
Diffraction Patterns

Analysis of light optical diffraction patterns produced by electron micrographs can easily lead to much nonsense. Such diffraction patterns are referred to as optical transforms and are compared with transforms produced by a variety of mathematical manipulations. In the use of light optical diffraction patterns to study periodicities in macromolecular ultrastructures, a number of potential pitfalls have been rediscovered. The limitations apply to the formation of the electron micrograph as well as its analysis.(1) The high resolution electron micrograph is itself a complex diffraction pattern resulting from the specimen, its stain, and its supporting substrate. Cowley and Moodie (Proc. Phys. Soc. B, LXX 497, 1957) demonstrated changing image patterns with changes in focus. Similar defocus images have been subjected to further light optical diffraction analysis.

The ultrastructure of coccoliths from the marine alga Emiliania huxleyi (Lohmann) Hay and Mohler: an ultra-high resolution electron microscope study

1983 ◽  
Vol 219 (1215) ◽  
pp. 111-117 ◽  
Keyword(s):  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Emiliania Huxleyi ◽  
Growth Patterns ◽  
Lattice Image ◽  
Nucleation Sites ◽  
Resolution Electron ◽  
Lattice Images ◽  
High Resolution Electron Microscope ◽  
Diffraction Patterns

The calcite coccoliths from the alga Emiliania huxleyi (Lohmann) Hay and Mohler have been studied by ultra-high resolution electron microscopy. This paper describes the two different types of structure observed, one in the upper elements, the other in the basal plate, or lower element. The former consisted of small, microdomain structures of 300-500 Å (1 Å = 10 -10 m) in length with no strong orientation. At places along these elements, and particularly in the junction between stem and head pieces, triangular patterns of lattice fringes were observed indicating multiple nucleation sites in the structure. In contrast, the lower element consisted of a very thin single crystalline sheet of calcite which could be resolved into a two dimensional lattice image, shown by a computer program that is capable of simulating electron diffraction patterns and lattice images to be a [421] zone of calcite. A possible mechanism for these growth patterns in the formation of coccoliths is discussed, together with the relevance of such mechanisms to biomineralization generally.

Atomic structure of YB56 studied by digital high-resolution electron microscopy and electron diffraction

2001 ◽  
Vol 16 (1) ◽  
pp. 101-107 ◽  
Author(s):  
Takeo Oku ◽  
Jan-Olov Bovin ◽  
Iwami Higashi ◽  
Takaho Tanaka ◽  
Yoshio Ishizawa
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
High Resolution Electron Microscopy ◽  
Charge Coupled Device ◽  
X Ray ◽  
Resolution Electron ◽  
High Resolution Images ◽  
Diffraction Patterns ◽  
Simulated Images

Atomic positions for Y atoms were determined by using high-resolution electron microscopy and electron diffraction. A slow-scan charge-coupled device camera which had high linearity and electron sensitivity was used to record high-resolution images and electron diffraction patterns digitally. Crystallographic image processing was applied for image analysis, which provided more accurate, averaged Y atom positions. In addition, atomic disordering positions in YB56 were detected from the differential images between observed and simulated images based on x-ray data, which were B24 clusters around the Y-holes. The present work indicates that the structure analysis combined with digital high-resolution electron microscopy, electron diffraction, and differential images is useful for the evaluation of atomic positions and disordering in the boron-based crystals.

Sign in / Sign up

Export Citation Format

Share Document