scholarly journals Optical diffraction of the Z lattice in canine cardiac muscle.

1977 ◽  
Vol 75 (3) ◽  
pp. 818-836 ◽  
Author(s):  
M A Goldstein ◽  
J P Schroeter ◽  
R L Sass
Keyword(s):  
Cardiac Muscle ◽  
Electron Micrographs ◽  
Cross Sections ◽  
Optical Diffraction ◽  
Square Lattice ◽  
Thin Sections ◽  
Diffraction Patterns ◽  
Nemaline Rods

Optical diffraction patterns from electron micrographs of both longitudinal and cross sections of normal and anomalous canine cardiac Z bands have been compared. The data indicate that anomalous cardiac Z bands resembling nemaline rods are structurally related to Z bands in showing a repeating lattice common to both. In thin sections transverse to the myofibril axis, both electron micrographs and optical diffraction patterns of the Z structure reveal a square lattice of 24 nm. This lattice is simple at the edge of each I band and centered in the interior of the Z band, where two distinct lattice forms have been observed. In longitudinal sections, oblique filaments visible in the electron micrographs correspond to a 38-nm axial periodicity in diffraction patterns of both Z band and Z rod. We conclude that the Z rods will be useful for further analysis and reconstruction of the Z lattice by optical diffraction techniques.

The Structure of the Macromolecular Units on the Cell Walls of Bacillus Polymyxa

1967 ◽  
Vol 2 (4) ◽  
pp. 587-591
Author(s):  
J. T. FINCH ◽  
A. KLUG ◽  
M.V. NERMUT
Keyword(s):  
Cell Wall ◽  
Electron Micrographs ◽  
Electron Scattering ◽  
Cell Walls ◽  
Single Layer ◽  
Optical Diffraction ◽  
Square Lattice ◽  
Bacillus Polymyxa ◽  
Optical Filtering ◽  
Diffraction Patterns

Electron micrographs of negatively stained preparations of cell walls of Bacillus polymyxa have been investigated by optical diffraction and optical filtering techniques. Images of single layers of the cell wall, from which the ‘noise’ has been filtered optically, show hollow, square-shaped morphological units arranged on a square lattice of side 100 Å. Single-layer images showing the same pattern have been filtered from moiré patterns arising from two overlapping single layers. The morphological units are composed of four smaller subunits. The optical diffraction patterns from regions of two overlapping layers show extra reflexions which are attributed to multiple electron scattering.

scholarly journals The Z lattice in canine cardiac muscle.

1979 ◽  
Vol 83 (1) ◽  
pp. 187-204 ◽  
Author(s):  
M A Goldstein ◽  
J P Schroeter ◽  
R L Sass
Keyword(s):  
Electron Micrographs ◽  
Cross Sections ◽  
Three Dimensional ◽  
Optical Diffraction ◽  
Section Thickness ◽  
Uniform Lattice ◽  
Cross Sectional ◽  
Regular Arrangement ◽  
Diffraction Patterns ◽  
Three Dimensional Models

Filtered images of mammalian cardiac Z bands were reconstructed from optical diffraction patterns from electron micrographs. Reconstructed images from longitudinal sections show connecting filaments at each 38-nm axial repeat in an array consistent with cross-sectional data. Some reconstructed images from cross sections indicate two distinctly different optical diffraction patterns, one for each of two lattice forms (basket weave and small square). Other images are more complex and exhibit composite diffraction patterns. Thus, the two lattice forms co-exist, interconvert, or represent two different aspects of the same details within the lattice. Two three-dimensional models of the Z lattice are presented. Both include the following features: a double array of axial filaments spaced at 24 nm, successive layers of tetragonally arrayed connecting filaments, projected fourfold symmetry in cross section, and layers of connecting filaments spaced at intervals of 38 nm along the myofibril axis. Projected views of the models are compared to electron micrographs and optically reconstructed images of the Z lattice in successively thicker cross sections. The entire Z band is rarely a uniform lattice regardless of plane of section or section thickness. Optical reconstructions strongly suggest two types of variation in the lattice substructure: (a) in the arrangement of connecting filaments, and (b) in the arrangement of units added side-to-side to make larger myofilament bundles and/or end-to-end to make wider Z bands. We conclude that the regular arrangement of axial and connecting filaments generates a dynamic Z lattice.

A comparison of the Three-Dimensional structures of Z bands in unstimulated and rigor skeletal muscle

1995 ◽  
Vol 53 ◽  
pp. 1080-1081
Author(s):  
J.P. Schroeter ◽  
R.J. Edwards ◽  
M.A. Goldstein
Keyword(s):  
Skeletal Muscle ◽  
Electron Micrographs ◽  
Cross Sections ◽  
Structural Transition ◽  
Three Dimensional ◽  
Square Lattice ◽  
Thin Sections ◽  
Tomographic Method ◽  
Dimensional Reconstruction ◽  
Rat Soleus Muscle

Previous studies (reviewed in ref. 1) lead to the expectation that Z bands from unstimulated skeletal muscle exhibit the unactivated small square form of the Z band lattice. Rigor Z bands, on the other hand are expected to exhibit the basket-weave form of the Z band lattice associated with activation in skeletal muscle. This Z band structural transition has been investigated by three-dimensional reconstruction of Z bands and nearby I bands in unstimulated and rigor rat soleus muscle. The reconstructions were calculated using the tomographic method of weighted back-projection on a series of electron micrographs of longitudinal thin sections of muscle.Examination of Z band cross-sections of the reconstructions reveals that the unstimulated muscle does indeed exhibit the expected small square lattice form. Furthermore, Z band cross sections of the rigor reconstructions reveal the expected basket-weave lattice form. The lattice dimensions were 20 +- 1 nra for the small square lattice and 27 +- 4 nm for the basket-weave lattice, consistent with the results from electron micrographs of cross-sections.

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.

Optical diffraction studies of myofibrillar structure

1971 ◽  
Vol 261 (837) ◽  
pp. 201-208 ◽  
Keyword(s):  
Electron Micrographs ◽  
Focal Length ◽  
Optical Diffraction ◽  
Myofibrillar Proteins ◽  
Electron Micrograph ◽  
X Ray Diffraction ◽  
Optical Filtering ◽  
X Ray ◽  
The Subject ◽  
Diffraction Patterns

We have used the techniques of optical diffraction and optical filtering to study electron micrographs of myofibrils and of paracrystals of myofibrillar proteins. The optical diffraction patterns provide information about periodic structure in the micrographs, and sometimes may reveal periodicities not apparent to the eye. We compare the optical diffraction patterns with the X-ray diffraction patterns obtained from living muscle, and this comparison can assist our interpretation of both the X-ray diffraction patterns and the electron micrographs. The optical diffractometer we have used is essentially similar to those described by Taylor & Lipson (1964), and by Klug & DeRosier (1966). The apparatus incorporates several refinements to facilitate operation. The recombining lens has a focal length, f , of about 1 m, and is placed so that the recombined image is formed at 2 f and has the same size as the subject. The diffraction subjects are not usually the electron micrographs themselves but copies on film. The film is of more uniform optical thickness than the glass electron micrograph, and is less fragile. Moreover, a set of films of varying contrast can be made from one micrograph.

Analysis of optical diffraction patterns from electron micrographs of lattices

1975 ◽  
Vol 99 (1) ◽  
pp. 143-151 ◽  
Author(s):  
Douglas H. Ohlendorf ◽  
Myra L. Collins ◽  
Leonard J. Banaszak
Keyword(s):  
Electron Micrographs ◽  
Optical Diffraction ◽  
Diffraction Patterns

scholarly journals An electron microscopic and optical diffraction analysis of the structure of Limulus telson muscle thick filaments.

1982 ◽  
Vol 92 (2) ◽  
pp. 443-451 ◽  
Author(s):  
R W Kensler ◽  
R J Levine
Keyword(s):  
Electron Microscopy ◽  
Diffraction Analysis ◽  
Electron Micrographs ◽  
Optical Diffraction ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Thick Filaments ◽  
Diffraction Patterns ◽  
Cross Bridges

Long, thick filaments (greater than 4.0 micrometer) rapidly and gently isolated from fresh, unstimulated Limulus muscle by an improved procedure have been examined by electron microscopy and optical diffraction. Images of negatively stained filaments appear highly periodic with a well-preserved myosin cross-bridge array. Optical diffraction patterns of the electron micrographs show a wealth of detail and are consistent with a myosin helical repeat of 43.8 nm, similar to that observed by x-ray diffraction. Analysis of the optical diffraction patterns, in conjunction with the appearance in electron micrographs of the filaments, supports a model for the filament in which the myosin cross-bridges are arranged on a four-stranded helix, with 12 cross-bridges per turn or each helix, thus giving an axial repeat every third level of cross-bridges (43.8 nm).

Electron Microscopic and Optical Diffraction Analyses of Crystalline Intranuclear Inclusions in Human Osteosarcoma Cells

1981 ◽  
Vol 39 ◽  
pp. 436-437
Author(s):  
Gonpachiro Yasuzumi
Keyword(s):  
Electron Micrographs ◽  
Periodic Structures ◽  
Bragg Reflection ◽  
Optical Diffraction ◽  
Intranuclear Inclusions ◽  
Osteosarcoma Cells ◽  
Electron Microscopic ◽  
Human Osteosarcoma ◽  
Human Osteosarcoma Cells ◽  
Diffraction Patterns

The fine structure of the crystalline intranuclear inclusions in the human osteosarcoma cells was studied by using a goniometer which tilted the specimen at angles of ±30° and ±40°. The results appear in the series of micrographs showing Fig. 1. At the point by the arrow, a helical structure is visible in two filaments. Optical diffrection patterns of selected areas of each negative electron micrograph film were taken by using a helium-neon laser as a source.A tentative model of the structure can be based on optical diffraction techniques applied to electron micrographs taken at different tilt angles. The diffraction pattern taken from image No. 0 in Fig. 1 is depicted in Fig. 2. Diffraction patterns from Nos. 3, 4 and 8 are shown in Figs. 3, 4 and 5. The contrast of some periodic structures can be eliminated in the image (extinction effect due to Bragg reflection of electron waves) by the interference of scattered waves from constituent elements. Hence it is rather important to interpret the electron micrographs and their optical diffraction patterns by considering the extinction effect of the image contrast.

Two structural states of Z-bands in cardiac muscle

1989 ◽  
Vol 256 (2) ◽  
pp. H552-H559 ◽  
Author(s):  
M. A. Goldstein ◽  
L. H. Michael ◽  
J. P. Schroeter ◽  
R. L. Sass
Keyword(s):  
Skeletal Muscle ◽  
Cardiac Muscle ◽  
Skeletal Muscles ◽  
Optical Diffraction ◽  
Square Lattice ◽  
Tetraacetic Acid ◽  
Repeat Distance ◽  
Thin Filaments ◽  
Resting Tension ◽  
Rat Papillary Muscle

We have compared the form and dimensions of the Z-band lattice in rat papillary muscle fixed at rest with and without ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) using electron microscopy and optical diffraction. In unstimulated muscle, the Z-band lattice form called basket weave predominated, and the Z-spacing (defined as the repeat distance of a tetragonal array of cross-cut thin filaments from the same sarcomere) was 23.93 +/- 0.37 nm. Muscles exposed to EGTA exhibited the small square-lattice form, and the Z-spacing was 20.50 +/- 0.19 nm. The Z-spacings in the two lattice forms were similar in cardiac and skeletal muscles such that the decrease in Z-spacing in the transition from basket weave to small square in this study was similar to the increase in Z-spacing previously demonstrated in skeletal muscle in the transition from small square to basket weave. The Z-lattice form and dimensions in unstimulated cardiac muscle resembled those in tetanized skeletal muscle. These findings are consistent with the higher resting tension in cardiac muscle and suggest that Ca2+ may be important for the maintenance of the expanded Z-lattice form.

An electron microscope study of synthetic graphite

1959 ◽  
Vol 253 (1274) ◽  
pp. 390-402 ◽  
Keyword(s):  
Electron Diffraction ◽  
Electron Micrographs ◽  
Stacking Faults ◽  
Grain Structure ◽  
Thin Sections ◽  
Average Value ◽  
Moire Patterns ◽  
Synthetic Graphite ◽  
Diffraction Patterns ◽  
Moiré Patterns

The ultra-microtome has been used to obtain thin sections of synthetic graphite blocks. The thickness of the sections was measured by shadowcasting and measuring the shadow length at appropriate edges. An average value of 150 Å was obtained. Transmission electron micrographs of thin sections showed moire patterns and the interrelation of these moire patterns revealed a characteristic grain structure in graphite akin to that seen in metals but with component microcrystals of smaller dimensions. The area of the individual micro - crystals forming the grain structure was measured and was found to be 0·11 + 0·074μ 2 . The boundary between neighbouring microcrystals was narrow and of around 50 A in width. Pores were visible at the junction of three or more contiguous microcrystals and were of diameter 400 to 800 Å. The selected-area electron diffraction technique was used to determine the orientation of individual microcrystals in the graphite sections. It was found that the hexagonal layer net planes were lying parallel or at a very small angle to the plane of the section. The electron diffraction patterns were also used to correlate the layer stacking faults in individual microcrystals both by counts of individual reflexions on the (1120) diffraction ring and by counts of the extra reflexions due to the long spacings between successive displaced layers. The average value of 13 Å found for the distance between successive stacking faults is equivalent to the distance between four hexagonal layer net planes. The moire patterns in the electron micrographs could be related to the long spacings in the electron diffraction patterns. It was possible to calculate the angle of twist between successive stacking faults from the long spacing or from the moire pattern. Dislocations were seen in many of the thin sections and were observed as extra terminating half-lines in the moire patterns; these dislocations were present in the hexagonal layer net planes themselves and indicated that there was in this region a considerable deformation of the benzenoid structure of the hexagonal layer nets. The measured frequency for their occurrence was 3·3 x 10 7 /cm 2 . Slip planes were also detected in some specimens.

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