The structure of actin filaments and the origin of the axial periodicity in the I -substance of vertebrate striated muscle

1964 ◽  
Vol 160 (981) ◽  
pp. 449-460 ◽  
Keyword(s):  
Skeletal Muscle ◽  
Electron Microscope ◽  
Actin Filaments ◽  
Striated Muscle ◽  
Rabbit Skeletal Muscle ◽  
Contractile Apparatus ◽  
Detailed Structure

Certain advances due mainly to H. E. Huxley (see Huxley 1961, 1963) have made it possible to use the electron microscope to study the detailed structure of the filaments in the contractile apparatus. The results of our work on actin filaments have already been published (Hanson & Lowy 1962, 1963). We shall now examine some of the consequences of these findings, including certain unsolved problems which they raise. Actin in the polymerized form ( F -actin) has been prepared from rabbit skeletal muscle by the usual methods and examined in negatively stained preparations in the electron microscope (Hanson & Lowy 1963). It has been found that solutions of F -actin are, in fact, suspensions of filaments. These consist of globular subunits arranged in a characteristic helical manner (figure 15).

scholarly journals Isolation of Nebulin from Rabbit Skeletal Muscle and Its Interaction with Actin

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Ryo Chitose ◽  
Atsushi Watanabe ◽  
Masato Asano ◽  
Akira Hanashima ◽  
Kouhei Sasano ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Column Chromatography ◽  
Salt Solution ◽  
Actin Filaments ◽  
Thin Filament ◽  
Full Length ◽  
Rabbit Skeletal Muscle ◽  
Native Form ◽  
20 Nm ◽  
Vertebrate Skeletal Muscle

Nebulin is about 800 kDa filamentous protein that binds the entire thin filament of vertebrate skeletal muscle sarcomeres. Nebulin cannot be isolated from muscle except in a completely denatured form by direct solubilization of myofibrils with SDS because nebulin is hardly soluble under salt conditions. In the present study, nebulin was solubilized by a salt solution containing 1 M urea and purified by DEAE-Toyopearl column chromatography via 4 M urea elution. Rotary-shadowed images of nebulin showed entangled knit-like particles, about 20 nm in diameter. The purified nebulin bound to actin filaments to form loose bundles. Nebulin was confirmed to bind actin,α-actinin,β-actinin, and tropomodulin, but not troponin or tropomyosin. The data shows that full-length nebulin can be also obtained in a functional and presumably native form, verified by data from experiments using recombinant subfragments.

The location of C-protein in rabbit skeletal muscle

1976 ◽  
Vol 192 (1109) ◽  
pp. 451-461 ◽  
Keyword(s):  
Skeletal Muscle ◽  
Electron Microscope ◽  
Psoas Muscle ◽  
Thick Filament ◽  
Rabbit Skeletal Muscle ◽  
C Protein ◽  
Rabbit Psoas ◽  
New Information ◽  
Protein Molecules

Antibodies to C-protein have been used to label fibres of glycerinated rabbit psoas muscle. The labelling patterns observed in the electron microscope show that C-protein is located on 7 stripes, spaced about 43 nm apart in each half of the A-band. Between two and four C-protein molecules per filament are present at each stripe. The labelling patterns also reveal the existence of two previously unrecognized components of the thick filament present in two further stripes in each half of the A-band. The location of C-protein and these other components accounts for many of the stripes seen in sections of the A-band and in negatively stained A-segments and provides new information on the packing of myosin molecules in the thick filament.

scholarly journals Mechanism of K+-induced actin assembly.

1982 ◽  
Vol 93 (3) ◽  
pp. 648-654 ◽  
Author(s):  
J D Pardee ◽  
J A Spudich
Keyword(s):  
Skeletal Muscle ◽  
Dictyostelium Discoideum ◽  
Actin Filaments ◽  
Atp Hydrolysis ◽  
Uv Spectroscopy ◽  
Rabbit Skeletal Muscle ◽  
Actin Assembly ◽  
Filament Formation ◽  
Monomeric Species ◽  
Rapid Formation

The assembly of highly purified actin from Dictyostelium discoideum amoebae and rabbit skeletal muscle by physiological concentrations of KCI proceeds through successive stages of (a) rapid formation of a distinct monomeric species referred to as KCI-monomer, (b) incorporation of KCI-monomers into an ATP-containing filament, and (c) ATP hydrolysis that occurs significantly after the incorporation event. KCI-monomer has a conformation which is distinct from that of either conventional G- or F-actin, as judged by UV spectroscopy at 210-220 nm and by changes in ATP affinity. ATP is not hydrolyzed during conversion of G-actin to KCI-monomer. KCI-monomer formation precedes filament formation and may be necessary for the assembly event. Although incorporation of KCI-monomers into filaments demonstrates lagphase kinetics by viscometry, both continuous absorbance monitoring at 232 nm and rapid sedimentation of filaments demonstrate hyperbolic assembly curves. ATP hydrolysis significantly lags the formation of actin filaments. When half of the actin has assembled, only 0.1 to 0.2 mole of ATP are hydrolyzed per mole of actin present as filaments.

The Ultrastructure of the White Striated Myotomal Muscle of the Cod, Gadus morhua

1967 ◽  
Vol 24 (12) ◽  
pp. 2549-2553 ◽  
Author(s):  
C. M. Bishop ◽  
P. H. Odense
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Cross Section ◽  
Actin Filaments ◽  
Gadus Morhua ◽  
Striated Muscle ◽  
Fish Muscle ◽  
Transverse Tubular System ◽  
Tubular System ◽  
Myotomal Muscle

The structure of the white skeletal muscle of the cod (Gadus morhua) is described. The peripheral fibrils are ribbon-like and rectangular in cross section with the long axis normal to the sarcolemma. The inner fibrils are mainly polygonal in cross section. Most of the mitochondria and nuclei are peripheral to the fibrils and next to the sarcolemma. The arrangement of the contractile proteins is typical for striated muscle, and the sarcoplasmic reticulum and transverse tubular system are similar to those in other white skeletal fish muscle. A distinct N-band is apparent with indications of branching and reorientation of the actin filaments. Mitochondria are often closely associated with the Z line.

The electron microscope as a diagnostic tool for skeletal muscle disease

1986 ◽  
Vol 44 ◽  
pp. 372-373
Author(s):  
J. E. Bilbao ◽  
R. A. Turner ◽  
R. T. King ◽  
J. C. Stinson
Keyword(s):  
Skeletal Muscle ◽  
Electron Microscope ◽  
Diagnostic Tool ◽  
Microscopic Examination ◽  
Striated Muscle ◽  
Electron Microscopic Examination ◽  
Muscle Disease ◽  
Electron Microscopic ◽  
Pathologic Physiology ◽  
Reaction Patterns

Time and experience has proven that striated muscle has only a limited number of reaction patterns. However, the electron microscopic examination has given information about the ultrastructural reaction of muscle fibers and about the pathologic physiology of diseased muscle. Although specific abnormalities are not useful when present individually. When present in a combination they may be diagnostic.

scholarly journals Myopathic changes in murine skeletal muscle lacking synemin

2015 ◽  
Vol 308 (6) ◽  
pp. C448-C462 ◽  
Author(s):  
Karla P. García-Pelagio ◽  
Joaquin Muriel ◽  
Andrea O'Neill ◽  
Patrick F. Desmond ◽  
Richard M. Lovering ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Striated Muscle ◽  
Contractile Apparatus ◽  
Lengthening Contractions ◽  
Tetanic Force ◽  
Type Iv ◽  
Fiber Size ◽  
Murine Skeletal Muscle ◽  
Fast Twitch ◽  
Myopathic Changes

Diseases of striated muscle linked to intermediate filament (IF) proteins are associated with defects in the organization of the contractile apparatus and its links to costameres, which connect the sarcomeres to the cell membrane. Here we study the role in skeletal muscle of synemin, a type IV IF protein, by examining mice null for synemin (synm-null). Synm-null mice have a mild skeletal muscle phenotype. Tibialis anterior (TA) muscles show a significant decrease in mean fiber diameter, a decrease in twitch and tetanic force, and an increase in susceptibility to injury caused by lengthening contractions. Organization of proteins associated with the contractile apparatus and costameres is not significantly altered in the synm-null. Elastimetry of the sarcolemma and associated contractile apparatus in extensor digitorum longus myofibers reveals a reduction in tension consistent with an increase in sarcolemmal deformability. Although fatigue after repeated isometric contractions is more marked in TA muscles of synm-null mice, the ability of the mice to run uphill on a treadmill is similar to controls. Our results suggest that synemin contributes to linkage between costameres and the contractile apparatus and that the absence of synemin results in decreased fiber size and increased sarcolemmal deformability and susceptibility to injury. Thus synemin plays a moderate but distinct role in fast twitch skeletal muscle.

Preparation, transfer and TEM observations of frozen hydrated muscle sections

1978 ◽  
Vol 36 (2) ◽  
pp. 92-93
Author(s):  
Ugo Valdrè ◽  
Michael Sjöström ◽  
Anne-Christine Edman
Keyword(s):  
Skeletal Muscle ◽  
Electron Microscope ◽  
Liquid Nitrogen ◽  
Nitrogen Atmosphere ◽  
Rabbit Skeletal Muscle ◽  
Muscle Fibres ◽  
Specimen Preparation ◽  
Native State ◽  
New Approach

IntroductionIdeally, biological specimens should be studied in their native state. Frozen hydrated sections of tissues, which are unfixed, unstained and unembedded, are closer to this state than material prepared with conventional techniques. Very recently some efforts have been devoted to the practical problems related to this new approach. The present work describes the methodology we have adopted, the techniques developed and some of the results obtained from frozen hydrated sections of muscle fibres.Materials and methodsThe major operations before observation in the electron microscope were the preparation and transfer of the specimens.A. Specimen preparation. Fresh pieces of rabbit skeletal muscle were frozen by rapid immersion in liquid nitrogen chilled Freon 12. Cryo-sectioning was carried out in nitrogen atmosphere at -100°C, or lower, using an LKB CryoKit equipped with items from LKB Cryotools. The sections were manipulated onto pre-cooled grids which were then transferred to a press assembly. Teflon weights were used to ensure successful attachment of the sections to the grid.

Staining terminal cisternae proteins in rat skeletal muscle triads: Selectivity of a new silver technique

1990 ◽  
Vol 48 (3) ◽  
pp. 736-737
Author(s):  
Carlos J Tandler ◽  
Amanda Pellegrino de Iraldi
Keyword(s):  
Skeletal Muscle ◽  
Acetic Acid ◽  
Electron Microscope ◽  
Gastrocnemius Muscle ◽  
Striated Muscle ◽  
Mercuric Acetate ◽  
Rat Skeletal Muscle ◽  
Ammoniacal Silver ◽  
Terminal Cisternae ◽  
Mechanism Of The Reaction

A selective silver staining of proteins within the lateral components of triads and diads in fixed striated muscle cells and in isolated sarcoplasmic reticulum vesicles using a mercuric acetate postflxation has been demonstrated by us.In the present work we modify the technique in order to study the mechanism of the reaction . First, the mercuric postfixation step was omitted and replaced by a treatment with diluted ammonia, a procedure thought to wash out the excess of the reducing aldehyde fixative. Second, a treatment with mercuric acetate was employed on the ammonia treated muscles. The rat gastrocnemius muscle was fixed by immersion (12-24 h) in 3% glutaraldehyde, washed briefly with water and placed (12-24 h) into an ammonia:distilled water (1:4 v/v) solution. After washing with water, 1% acetic acid and water, muscles were treated overnight with 50% (v/v) ammoniacal silver nitrate at 37°C in darkness, washed with three changes of 5% (w/v) sodium sulphite and water, embedded in Poly B, sectioned and examined unstained with a Siemens Elmiskop I electron microscope.

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