Phosphorylation kinetics of skeletal muscle myosin and the effect of phosphorylation on actomyosin ATPase activity

Biochemistry ◽  
1984 ◽  
Vol 23 (18) ◽  
pp. 4144-4150 ◽  
Author(s):  
Anthony Persechini ◽  
James T. Stull
Keyword(s):  
Skeletal Muscle ◽  
Atpase Activity ◽  
Skeletal Muscle Myosin ◽  
Actomyosin Atpase ◽  
Muscle Myosin ◽  
Kinetics Of

scholarly journals The effects of caldesmon on the ATPase activities of rabbit skeletal-muscle myosin

1986 ◽  
Vol 238 (2) ◽  
pp. 523-530 ◽  
Author(s):  
M S Lim ◽  
M P Walsh
Keyword(s):  
Skeletal Muscle ◽  
Atpase Activity ◽  
Striated Muscle ◽  
Physiological Activity ◽  
Skeletal Muscle Myosin ◽  
Contractile State ◽  
Calmodulin Binding ◽  
Muscle Tissues ◽  
Troponin Complex ◽  
Muscle Myosin

We studied the effects of caldesmon, a major actin- and calmodulin-binding protein found in a variety of muscle and non-muscle tissues, on the various ATPase activities of skeletal-muscle myosin. Caldesmon inhibited the actin-activated myosin Mg2+-ATPase, and this inhibition was enhanced by tropomyosin. In the presence of the troponin complex and tropomyosin, caldesmon inhibited the Ca2+-dependent actomyosin Mg2+-ATPase; this inhibition could be partly overcome by Ca2+/calmodulin. Caldesmon, phosphorylated to the extent of approximately 4 mol of Pi/mol of caldesmon, inhibited the actin-activated myosin Mg2+-ATPase to the same extent as did non-phosphorylated caldesmon. Both inhibitions could be overcome by Ca2+/calmodulin. Caldesmon also inhibited the Mg2+-ATPase activity of skeletal-muscle myosin in the absence of actin; this inhibition also could be overcome by Ca2+/calmodulin. Caldesmon inhibited the Ca2+-ATPase activity of skeletal-muscle myosin in the presence or absence of actin, at both low (0.1 M-KCl) and high (0.3 M-KCl) ionic strength. Finally, caldesmon inhibited the skeletal-muscle myosin K+/EDTA-ATPase at 0.1 M-KCl, but not at 0.3 M-KCl. Addition of actin resulted in no inhibition of this ATPase by caldesmon at either 0.1 M- or 0.3 M-KCl. These observations suggest that caldesmon may function in the regulation of actin-myosin interactions in striated muscle and thereby modulate the contractile state of the muscle. The demonstration that caldesmon inhibits a variety of myosin ATPase activities in the absence of actin indicates a direct effect of caldesmon on myosin. The inhibition of the actin-activated Mg2+-ATPase activity of myosin (the physiological activity) may not be due therefore simply to the binding of caldesmon to the actin filament causing blockage of myosin-cross-bridge-actin interaction.

scholarly journals Chick brain actin and myosin. Isolation and characterization.

1979 ◽  
Vol 80 (2) ◽  
pp. 341-355 ◽  
Author(s):  
E R Kuczmarski ◽  
J L Rosenbaum
Keyword(s):  
Skeletal Muscle ◽  
Molecular Weight ◽  
Atpase Activity ◽  
Molecular Sieve ◽  
Acetone Powder ◽  
Chick Brain ◽  
Skeletal Muscle Myosin ◽  
Isolation And Characterization ◽  
Muscle Myosin ◽  
The Brain

Brain actin extracted from an acetone powder of chick brains was purified by a cycle of polymerization-depolymerization followed by molecular sieve chromatography. The brain actin had a subunit molecular weight of 42,000 daltons as determined by co-electrophoresis with muscle actin. It underwent salt-dependent g to f transformation to form double helical actin filaments which could be "decorated" by muscle myosin subfragment 1. A critical concentration for polymerization of 1.3 microM was determined by measuring either the change in viscosity or absorbance at 232 nm. Brain actin was also capable of stimulating the ATPase activity of muscle myosin. Brain myosin was isolated from whole chick brain by a procedure involving high salt extraction, ammonium sulfate fractionation and molecular sieve chromatography. The purified myosin was composed of a 200,000-dalton heavy chain and three lower molecular weight light chains. In 0.6 M KCl the brain myosin had ATPase activity which was inhibited by Mg++, stimulated by Ca++, and maximally activated by EDTA. When dialyzed against 0.1 M KCl, the brain myosin self-assembled into short bipolar filaments. The bipolar filaments associated with each other to form long concatamers, and this association was enhanced by high concentrations of Mg++ ion. The brain myosin did not interact with chicken skeletal muscle myosin to form hybrid filaments. Furthermore, antibody recognition studies demonstrated that myosins from chicken brain, skeletal muscle, and smooth muscle were unique.

IV. The mechanism of contraction - Introductory remarks

1973 ◽  
Vol 265 (867) ◽  
pp. 167-167
Keyword(s):  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Atpase Activity ◽  
Soluble Proteins ◽  
Smooth Muscle Myosin ◽  
Trypsin Treatment ◽  
Skeletal Muscle Myosin ◽  
Muscle Myosin

Our programme this afternoon is in two parts. We first welcome Professor Hamoir and Dr Kendrick-Jones to describe the several ways in which smooth muscle myosin differs from skeletal muscle myosin. It was in this biochemical field that my own work, with Dr Jennifer Williams, lay some twelve years ago. We were impressed at that time by the very low ATPase activity of the uterus actomyosin, and by the fact that on trypsin treatment meromyosins were obtained in some ways similar to those of skeletal muscle. Speakers this afternoon will have far more to tell us of the nature, behaviour and structure of the myosins concerned. We were also interested in the properties and possible function of certain soluble proteins, including tropomyosin, which figure so largely in smooth muscle constitution. This subject also will come up today.

scholarly journals A comparison of the effects of calponin on smooth and skeletal muscle actomyosin systems in the presence and absence of caldesmon

1992 ◽  
Vol 288 (3) ◽  
pp. 733-739 ◽  
Author(s):  
S J Winder ◽  
C Sutherland ◽  
M P Walsh
Keyword(s):  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Smooth Muscle Actin ◽  
Smooth Muscle Myosin ◽  
Muscle Actin ◽  
Heavy Meromyosin ◽  
Muscle System ◽  
Skeletal Muscle Myosin ◽  
Actomyosin Atpase ◽  
Muscle Myosin

Thiosphosphorylated smooth muscle myosin and skeletal muscle myosin, both of which express Ca(2+)-independent actin-activated MgATPase activity, were used to examine the functional effects of calponin and caldesmon separately and together. Separately, calponin and caldesmon inhibited the actin-activated MgATPase activities of thiophosphorylated smooth muscle myosin and skeletal muscle myosin, calponin being significantly more potent in both systems. Calponin-mediated inhibition resulted from the interaction of calponin with actin since it could be reversed by increasing the actin concentration. Caldesmon had no significant influence on the calponin-induced inhibition of the smooth muscle actomyosin ATPase, nor did calponin have a significant effect on caldesmon-induced inhibition. In the skeletal muscle system, however, caldesmon was found to override the inhibitory effect of calponin. This difference probably reflects the lower affinity of skeletal muscle actin for calponin compared with that of smooth muscle actin. Calponin inhibition of skeletal muscle actin-activated myosin MgATPase was not significantly affected by troponin/tropomyosin, suggesting that the thin filament can readily accommodate calponin in addition to the troponin complex, or that calponin may be able to displace troponin. Calponin also inhibited acto-phosphorylated smooth muscle heavy meromyosin and acto-skeletal muscle heavy meromyosin MgATPases. The most appropriate protein preparations for analysis of the regulatory effects of calponin in the actomyosin system therefore would be smooth muscle actin, tropomyosin and thiophosphorylated myosin, and for analysis of the kinetic effects of calponin on the actomyosin ATPase cycle they would be smooth muscle actin, tropomyosin and phosphorylated heavy meromyosin, due to the latter's solubility.

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