Probe studies of the magnesium ADP state of muscle cross-bridges: microscopic and wavelength-dependent fluorescence polarization from 1,5-[[[(iodoacetyl)amino]ethyl]amino]naphthalene-1-sulfonic acid labeled myosin subfragment 1 decorating muscle fibers

Biochemistry ◽  
1987 ◽  
Vol 26 (14) ◽  
pp. 4517-4523 ◽  
Author(s):  
Katalin Ajtai ◽  
Thomas P. Burghardt
Keyword(s):  
Fluorescence Polarization ◽  
Sulfonic Acid ◽  
Muscle Fibers ◽  
Myosin Subfragment ◽  
Myosin Subfragment 1 ◽  
Cross Bridges

scholarly journals X-ray diffraction from skeletal muscle fibers with diffused Dictyostelium G680V myosin subfragment-1

2003 ◽  
Vol 43 (supplement) ◽  
pp. S129
Author(s):  
H. Iwamoto ◽  
T. Uyeda ◽  
E. Katayama ◽  
J. Wakayama ◽  
T. Tamura ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Skeletal Muscle Fibers ◽  
Myosin Subfragment ◽  
Myosin Subfragment 1

ADP release from myosin in permeabilized smooth muscle

1989 ◽  
Vol 256 (1) ◽  
pp. C59-C66 ◽  
Author(s):  
T. M. Butler ◽  
D. S. Pacifico ◽  
M. J. Siegman
Keyword(s):  
Smooth Muscle ◽  
Light Chains ◽  
Myosin Light Chains ◽  
Myosin Subfragment ◽  
Myosin Subfragment 1 ◽  
Adp Release ◽  
The Difference ◽  
Portal Veins ◽  
Cross Bridges ◽  
Muscle Myosin

The purpose of this study was to determine the nucleotide bound to myosin and its rate of release under relaxed and activated conditions in permeabilized rabbit portal veins. Incubation of the muscles in a relaxing solution containing [3H]-ATP resulted in the formation of 60-70 microM radiolabeled ADP in the muscle whether or not the myosin light chains had been thiophosphorylated. This value was similar to the estimate of the concentration of myosin subfragment 1. Upon transfer of the muscles to a chase solution containing no labeled ATP, there was a very slow loss of labeled ADP when the light chains were unphosphorylated, but a much faster release occurred when the light chains were thiophosphorylated. The results suggest that smooth muscle myosin exists primarily in a complex with ADP under both relaxed and phosphorylated conditions and that phosphorylation of all of the light chains results in a large increase in the rate of release of the products of ATP splitting from all of the myosin. Interestingly, the exponential release of ADP in relaxed muscle shows two components, one of which contains about two-thirds of the total ADP and is 5- to 10-fold faster than the other. If the difference in rates of ADP release observed in relaxed muscle persists when the myosin is phosphorylated, then it is possible that there is a 5- to 10-fold difference in rates of cycling for different phosphorylated cross bridges in smooth muscle.

Structure of Myosin Subfragment-1 from Electron Microscopy and Crystallography

1988 ◽  
Vol 46 ◽  
pp. 156-157
Author(s):  
Donald A. Winkelmann
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Actin Filaments ◽  
Light Chains ◽  
Myosin Filament ◽  
Primary Role ◽  
Heavy Chains ◽  
Myosin Subfragment ◽  
Myosin Subfragment 1 ◽  
Globular Head

The primary role of the interaction of actin and myosin is the generation of force and motion as a direct consequence of the cyclic interaction of myosin crossbridges with actin filaments. Myosin is composed of six polypeptides: two heavy chains of molecular weight 220,000 daltons and two pairs of light chains of molecular weight 17,000-23,000. The C-terminal portions of the myosin heavy chains associate to form an α-helical coiled-coil rod which is responsible for myosin filament formation. The N-terminal portion of each heavy chain associates with two different light chains to form a globular head that binds actin and hydrolyses ATP. Myosin can be fragmented by limited proteolysis into several structural and functional domains. It has recently been demonstrated using an in vitro movement assay that the globular head domain, subfragment-1, is sufficient to cause sliding movement of actin filaments.The discovery of conditions for crystallization of the myosin subfragment-1 (S1) has led to a systematic analysis of S1 structure by x-ray crystallography and electron microscopy. Image analysis of electron micrographs of thin sections of small S1 crystals has been used to determine the structure of S1 in the crystal lattice.

scholarly journals Studies of Ligand-induced Conformational Perturbations in Myosin Subfragment 1

1989 ◽  
Vol 264 (18) ◽  
pp. 10810-10819
Author(s):  
K N Rajasekharan ◽  
M Mayadevi ◽  
M Burke
Keyword(s):  
Myosin Subfragment ◽  
Myosin Subfragment 1
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