A subunit of myosin

Kominz, David R.; Carroll, William R.; Smith, E.N.; Mitchell, Ellis R.

doi:10.1016/0003-9861(59)90395-9

Cited by 89 publications

(32 citation statements)

References 19 publications

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“…No details, however, have been published on this observation. The light component isolated at alkaline pH was found to have a C-terminal group, isoleucine (51). Isoleucine had previously been described as the Cterminal group of myosin (53), and more recently has been found to be the Cterminal group of H-meromyosin (54).…”

Section: S U B U N I T S O F M Y O S I Nmentioning

confidence: 98%

“…The question of alkali dissociation of myosin was next studied by Kominz, Carroll, Smith, and Mitchell (51). Preparations of myosin isolated by several methods, including ammonium sulfate fractionation, were dialyzed against 0.1 M sodium carbonate at about pH 10.…”

Section: S U B U N I T S O F M Y O S I Nmentioning

confidence: 99%

“…Isoleucine had previously been described as the Cterminal group of myosin (53), and more recently has been found to be the Cterminal group of H-meromyosin (54). The amino acid compositions of the light components isolated at alkaline pH and in urea solution were also determined (51). Comparison with the amino acid composition of the meromyosins is of interest (43), and Table I summarizes data on those residues which are significantly different in Lmeromyosin and in H-meromyosin.…”

Section: S U B U N I T S O F M Y O S I Nmentioning

confidence: 99%

“…Much of these data were obtained after the original work on the light alkali component (51), and their implications were by no means evident in 1960, when a crucial study (9) on the subunit composition of myosin was reported.…”

Section: S U B U N I T S O F M Y O S I Nmentioning

confidence: 99%

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Myosin

Dreizen

Gershman

Trotta

et al. 1967

The Journal of General Physiology

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There is fairly general agreement that myosin isolated from rabbit skeletal muscle has a molecular weight of about 500,000. The higher values that have been reported apparently reflect protein aggregation related to the method of preparation. On the basis of present evidence, the myosin molecule has an elongate helical core of two f subunits (average weight about 215,000) that extend into a globular head region containing three g subunits (average weight about 20,000). Myosin may be dissociated into subunits by a number of methods. In 5 M guanidine, the myosin molecule is dissociated into f and g subunits, while at pH above 10, the g subunits are dissociated from the intact fibrous core of myosin. The dissociation of g subunits at pH 10 is accompanied by the loss of both ATPase activity and actin-binding capacity; however, the exact biological significance of the g subunits is presently uncertain. In preliminary studies, the f subunits appear to contain the sulfhydryl residues currently implicated in myosin ATPase, and there is some indication of allosteric regulation of enzymic activity.

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Section: S U B U N I T S O F M Y O S I Nmentioning

confidence: 98%

Section: S U B U N I T S O F M Y O S I Nmentioning

confidence: 99%

Section: S U B U N I T S O F M Y O S I Nmentioning

confidence: 99%

Section: S U B U N I T S O F M Y O S I Nmentioning

confidence: 99%

See 2 more Smart Citations

Myosin

Dreizen

Gershman

Trotta

et al. 1967

The Journal of General Physiology

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“…A limited number of experiments was conducted in the presence of 1 mM MgCI, or 1 mM CaCI,. MATERIALS [12]. Contaminating actomyosin was contracted and precipitated by the addition of ATP, MgCl, and KCl and removed by centrifugation for 2 hours at 59,000 x g. The myosin A was filtered twice through glass wool and precipitated three times by dilution I :15.…”

Section: ~mentioning

confidence: 99%

The Binding of ATP to Myosins B and A

Bowen

Evans

1968

Eur J Biochem

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Values for binding of ATP and ADP to myosin B and ATP to myosin A were determined from mixtures of these nucleotides and proteins by use of rapid filtration to separate bound and unbound nucleotides and by use of an ATP-regenerating system (creatine phosphate-creatine phosphokinase). Calculation of the binding curves of ATP to lo5 g of myosin B by the mass law binding expression using two sets of binding sites, n, and n2, and with binding constants, k1 = 40 x lo3 and k2 = 1.5 x lo3 I/mole, respectively, yielded a curve of good fit to the experimentally determined points when n, = 0.4 and n, = 1.2 moles per lo5 g. Similar calculation of data from binding of ATP to myosin A yielded a curve of best fit when n1 = 0.5 and n, = 3.0 per lo5 g with k, = 5,500 and k, = 550 l/mole. At 1 mM ATP, myosin A bound 50 more than myosin B. ADP a t 1 mM appeared to saturate myosin B about 970/,. The amounts of ADP bound to myosin B fitted a curvc with one value of n which equaled 0.36. We have measured the binding of ATP to myosinB and myosinA in a more direct manner than the above workers, except possibly for Chaplain [9], and at concentrations as high as 1 mM. The amounts bound were considered t o be equal to the decrease in concentration of ATP when ATP was rapidly mixed with precipitated myosin and the free ATP immediately separated by filtration. An enzymatic rephosphorylating system (creatine phosphate pZus creatine phosphokinase) regenerated ATP from ADP. A limited number of experiments was conducted in the presence of 1 mM MgCI, or 1 mM CaCI,. MATERIALS AND METHODSMyosin B was prepared essentially according to Szent-Gyorgyi [lo] by extraction of ground rabbit muscle with alkaline 0.6 M KC1 for 20 hours a t 4", followed by dilution of the proteins and filtration twice through cheesecloth. It was precipitated three

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Dynamic aspects of structural proteins in vertebrate skeletal muscle

et al. 1981

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In this review, our current knowledge on the structural proteins of vertebrate skeletal muscle is briefly outlined. Structural proteins include the contractile proteins (actin and myosin), the major regulatory proteins (troponin and tropomyosin), the minor regulatory proteins (M-protein, C-protein, F-protein, I-protein, and actinins), and the scaffold proteins (connectin, desmin, and Z-protein). In addition, the relative turnover rates of the muscle proteins (M-protein greater than or equal to troponin greater than soluble protein as a whole greater than tropomyosin not equal to alpha-actinin greater than myosin greater than 10S-actinin greater than actin) are discussed. The changes in the turnover of muscle proteins are compared in denervated and dystrophic muscles. The properties of the various proteases in muscle, including alkaline protease, calcium-activated neutral protease (CANP), and acidic protease (cathepsins), and the structural alterations of myofibrils by these proteases are also described. Finally, the role of proteases and their inhibitors in diseased muscle is summarized, with focus on CANP and its inhibitors, leupeptin and E-64.

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A subunit of myosin

Cited by 89 publications

References 19 publications

Myosin

Myosin

The Binding of ATP to Myosins B and A

Dynamic aspects of structural proteins in vertebrate skeletal muscle

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