Combined use of freeze-fracture electron microscopy and X-ray diffraction for the structure determination of three-dimensionally ordered specimens

1994 ◽  
Vol 80 (2-3) ◽  
pp. 193-201 ◽  
Author(s):  
T GULIKKRZYWICKI
Keyword(s):  
Electron Microscopy ◽  
Structure Determination ◽  
Freeze Fracture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Combined Use ◽  
Freeze Fracture Electron Microscopy ◽  
Fracture Electron

scholarly journals Structural states of myelin observed by x-ray diffraction and freeze-fracture electron microscopy.

1979 ◽  
Vol 82 (1) ◽  
pp. 140-149 ◽  
Author(s):  
D A Kirschner ◽  
C J Hollingshead ◽  
C Thaxton ◽  
D L Caspar ◽  
D A Goodenough
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Freeze Fracture ◽  
Intermediate Structure ◽  
X Ray Diffraction ◽  
Membrane Unit ◽  
X Ray ◽  
Critical Measure ◽  
Freeze Fracture Electron Microscopy ◽  
Fracture Electron

Coordinated freeze-fracture electron microscopy and x-ray diffraction were used to visualize the morphological relation between compacted and native period membrane arrays in myelinated nerves treated with dimethylsulfoxide (DMSO). Comparison of x-ray diffraction at room temperature and at low temperature was used as a critical measure of the extent of structural preservation. Our x-ray diffraction patterns show that in the presence of cryoprotective agents, it is possible to preserve with only small changes the myelin structure which exists at room temperature. These changes include a slight increase in packing disorder of the membrane, a small, negative thermal expansion of the membrane unit, and some reorganization in the cytoplasmic half of the bilayer. The freeze-fracture electron microscopy clearly demonstrates continuity of compact and native period phases in DMSO-treated myelin. Finally, the use of freezing to trap the transient, intermediate structure during a structural transition in glycerol is demonstrated.

scholarly journals The crystal lattice of Paramecium trichocysts before and after exocytosis by X-ray diffraction and freeze-fracture electron microscopy.

1987 ◽  
Vol 105 (4) ◽  
pp. 1649-1662 ◽  
Author(s):  
L Sperling ◽  
A Tardieu ◽  
T Gulik-Krzywicki
Keyword(s):  
Electron Microscopy ◽  
Freeze Fracture ◽  
X Ray ◽  
Before And After ◽  
Ordered Array ◽  
Extracellular Form ◽  
Freeze Etching ◽  
Freeze Fracture Electron Microscopy ◽  
Genetically Determined ◽  
Fracture Electron

Paramecium trichocysts are unusual secretory organelles in that: (a) their crystalline contents are built up from a family of low molecular mass acidic proteins; (b) they have a precise, genetically determined shape; and (c) the crystalline trichocyst contents expand rapidly upon exocytosis to give a second, extracellular form which is also an ordered array. We report here the first step of our study of trichocyst structure. We have used a combination of x-ray powder diffraction, freeze-etching, and freeze-fracture electron microscopy of isolated, untreated trichocysts, and density measurements to show that trichocyst contents are indeed protein crystals and to determine the elementary unit cell of both the compact intracellular and the extended extracellular form.

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