Shape and flexibility of the myosin molecule

Elliott, A.; Offer, Gerald

doi:10.1016/0022-2836(78)90204-8

Cited by 321 publications

(168 citation statements)

References 25 publications

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“…Following the proposal of John Haselgrove, based on X-ray diffraction analysis, the 3D map densities were interpreted as repeated features containing two equally sized domains springing from a common region on the backbone which looks very much like the individual myosin molecules images seen in shadowed preparations (Fig. 4b1) (Elliott and Offer 1978) or in negatively stained filaments with extended heads (Knight and Trinick 1984). This suggested that the heads were pointing in opposite directions along the thick filament axis (Haselgrove 1980;Levine et al 1982).…”

Section: Why Tarantula Muscle?mentioning

confidence: 93%

Lessons from a tarantula: new insights into muscle thick filament and myosin interacting-heads motif structure and function

et al. 2017

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The tarantula skeletal muscle X-ray diffraction pattern suggested that the myosin heads were helically arranged on the thick filaments. Electron microscopy (EM) of negatively stained relaxed tarantula thick filaments revealed four helices of heads allowing a helical 3D reconstruction. Due to its low resolution (5.0 nm), the unambiguous interpretation of densities of both heads was not possible. A resolution increase up to 2.5 nm, achieved by cryo-EM of frozen-hydrated relaxed thick filaments and an iterative helical real space reconstruction, allowed the resolving of both heads. The two heads, Bfree^and Bblocked^, formed an asymmetric structure named the Binteracting-heads motif^(IHM) which explained relaxation by self-inhibition of both heads ATPases. This finding made tarantula an exemplar system for thick filament structure and function studies. Heads were shown to be released and disordered by Ca 2+ -activation through myosin regulatory light chain phosphorylation, leading to EM, small angle X-ray diffraction and scattering, and spectroscopic and biochemical studies of the IHM structure and function. The results from these studies have consequent implications for understanding and explaining myosin super-relaxed state and thick filament activation and regulation. A cooperative phosphorylation mechanism for activation in tarantula skeletal muscle, involving swaying constitutively Ser35 mono-phosphorylated free heads, explains super-relaxation, force potentiation and posttetanic potentiation through Ser45 mono-phosphorylated blocked heads. Based on this mechanism, we propose a swaying-swinging, tilting crossbridge-sliding filament for tarantula muscle contraction.

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Section: Why Tarantula Muscle?mentioning

confidence: 93%

Lessons from a tarantula: new insights into muscle thick filament and myosin interacting-heads motif structure and function

et al. 2017

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“…Furthermore, the density of the different positions varied. Two out of 51 filaments were well-preserved along the whole length and, in these, the labeling repeat was 15.2 + 0.4 nm in the cross-bridge region and 15.3 + 0.4 nm in M-plus P-zones (stripes [1][2][3][4][5][6][7][8][9][10][11][12]. The distance between stripes 1 and l' of these two thick filaments was 15.5 and 16.6 nm, which again suggests that the l-l' spacing is greater than that between other adjacent stripes of the A-band.…”

Section: Negative Staining Of Native Thick Filamentsmentioning

confidence: 99%

Axial arrangement of the myosin rod in vertebrate thick filaments: immunoelectron microscopy with a monoclonal antibody to light meromyosin.

Shimizu¹,

Dennis²,

Masaki³

et al. 1985

The Journal of Cell Biology

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A monoclonal antibody, MF20, which has been shown previously to bind the myosin heavy chain of vertebrate striated muscle, has been proven to bind the light meromyosin (LMM) fragment by solid phase radioimmune assay with alpha-chymotryptic digests of purified myosin. Epitope mapping by electron microscopy of rotary-shadowed, myosinantibody complexes has localized the antibody binding site to LMM at a point ~92 nm from the C-terminus of the myosin heavy chain. Since this epitope in native thick filaments is accessible to monoclonal antibodies, we used this antibody as a high affinity ligand to analyze the packing of LMM along the backbone of the thick filament. By immunofluorescence microscopy, MF20 was shown to bind along the entire A-band of chicken pectoralis myofibrils, although the epitope accessibility was greater near the ends than at the center of the A-bands. Thin-section, transmission electron microscopy of myofibrils decorated with MF20 revealed 50 regularly spaced, cross-striations in each half A-band, with a repeat distance of ~13 nm. These were numbered consecutively, 1-50, from the A-band to the last stripe, ~68 nm from the filament tips. These same striations could be visualized by negative staining of native thick filaments labeled with MF20. All 50 striations were of a consecutive, uninterrupted repeat which approximated the 14-15-nm axial translation of cross-bridges. Each half M-region contained five MF20 striations (~13 nm apart) with a distance between stripes 1 and 1', on each half of the bare zone, of ~18 nm. This is compatible with a packing model with full, antiparallel overlap of the myosin rods in the bare zone region. Differences in the spacings measured with negatively stained myofilaments and thin-sectioned myofibrils have been shown to arise from specimen shrinkage in the fixed and embedded preparations.These observations provide strong support for Huxley's original proposal for myosin packing in thick filaments of vertebrate muscle (Huxley, H. E., 1963, J. Mol. Biol., 7:281-308) and, for the first time, directly demonstrate that the 14-15-nm axial translation of LMM in the thick filament backbone corresponds to the cross-bridge repeat detected with x-ray diffraction of living muscle.The thick myofilaments of vertebrate skeletal muscle are complex polymeric structures composed predominantly of myosin but also contain a set of minor proteins including Mprotein (32, 50), C-protein (34, 40), myomesin (16), M-creatine kinase (51), H-protein (6), AMP deaminase (1), endprotein (49), and titin or connectin (31,54).A basic model for the structure of thick filaments was first described by H. E. Huxley (22). Based on electron microscopy

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“…It is of interest to note in this connection that the myosin head (approximately 17 nm long and 6 nm wide; Elliott & Offer, 1978;Rayment et al, 1993) is large enough to fill the entire gap between the thick and thin filaments near slack fibre length, the side-to-side distance between the two filaments being 17.2 nm at 1.8 µm sarcomere length. (The estimation of the interfilament spacing is based on published data on the 1.0 lattice spacing of the X-ray diffraction pattern and on electron microscopical measurements of filament diameters; for details see Edman, 1999).…”

Section: Force Enhancement By Stretchmentioning

confidence: 99%

Contractile Performance of Striated Muscle

Edman

2010

Advances in Experimental Medicine and Biology

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The single muscle fibre preparation provides an excellent tool for studying the mechanical behaviour of the contractile system at sarcomere level. The present article gives an overview of studies based on intact single fibres from frog and mouse skeletal muscle. The following aspects of muscle function are treated: 1.The length-tension relationship. 2. The biphasic force-velocity relationship. 3. The maximum speed of shortening, its independence of sarcomere length and degree of activation. 4. Force enhancement during stretch, its relation to sarcomere length and myofilament lattice width. 5. Residual force enhancement after stretch.6. Force reduction after loaded shortening. 7. Deactivation by active shortening. 8.Differences in kinetic properties along individual muscle fibres.3

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Shape and flexibility of the myosin molecule

Cited by 321 publications

References 25 publications

Lessons from a tarantula: new insights into muscle thick filament and myosin interacting-heads motif structure and function

Lessons from a tarantula: new insights into muscle thick filament and myosin interacting-heads motif structure and function

Axial arrangement of the myosin rod in vertebrate thick filaments: immunoelectron microscopy with a monoclonal antibody to light meromyosin.

Contractile Performance of Striated Muscle

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