scholarly journals Calmodulin and myosin light-chain kinase of rabbit fast skeletal muscle

1979 ◽  
Vol 179 (1) ◽  
pp. 89-97 ◽  
Author(s):  
A C Nairn ◽  
S V Perry
Keyword(s):  
Skeletal Muscle ◽  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Troponin I ◽  
Maximal Activity ◽  
Bovine Brain ◽  
Affinity Column ◽  
Fast Skeletal Muscle ◽  
Skeletal Muscle Myosin

1. It is confirmed that myosin light-chain kinase is a protein of mol.wt. about 80,000 that is inactive in the absence of calmodulin. 2. In the presence of 1 mol of calmodulin/mol of kinase 80-90% of the maximal activity is obtained. 3. Crude preparations of the whole light-chain fraction of rabbit fast-skeletal-muscle myosin contain enough calmodulin to activate the enzyme. A method for the preparation of calmodulin-free P light chain is described. 4. A procedure is described for the isolation of calmodulin from rabbit fast skeletal muscle. 5. Rabbit fast-skeletal-muscle calmodulin is indistinguishable from bovine brain calmodulin in its ability to activate myosin light-chain kinase. The other properties of these two proteins are also very similar. 6. Rabbit fast-skeletal-muscle troponin C was about 10% as effective as calmodulin as activator for myosin light-chain kinase. 7. By chromatography on a Sepharose-calmodulin affinity column evidence was obtained for the formation of a Ca2+-dependent complex between calmodulin and myosin light-chain kinase. 8. Troponin I from rabbit fast skeletal muscle and histone IIAS were phosphorylated by fully activated myosin light-chain kinase at about 1% of the rate of the P light chain.

Shape and substructure of skeletal muscle myosin light chain kinase

Biochemistry ◽  
1983 ◽  
Vol 22 (18) ◽  
pp. 4316-4326 ◽  
Author(s):  
Georg W. Mayr ◽  
Ludwig M. G. Heilmeyer
Keyword(s):  
Skeletal Muscle ◽  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Skeletal Muscle Myosin ◽  
Muscle Myosin

scholarly journals Myosin light-chain phosphatase

1976 ◽  
Vol 157 (3) ◽  
pp. 687-697 ◽  
Author(s):  
M Morgan ◽  
S V Perry ◽  
J Ottaway
Keyword(s):  
Skeletal Muscle ◽  
Light Chain ◽  
Sodium Dodecyl Sulphate ◽  
Myosin Light Chain Kinase ◽  
Adenosine Triphosphatase ◽  
Myosin Light Chain ◽  
Sodium Dodecyl ◽  
Affinity Column ◽  
Heavy Meromyosin ◽  
Myosin Light Chain Phosphatase

1. A method for the isolation of a new enzyme, myosin light-chain phosphatase, from rabbit white skeletal muscle by using a Sepharose-phosphorylated myosin light-chain affinity column is described. 2. The enzyme migrated as a single component on electrophoresis in sodium dodecyl sulphate/polyacrylamide gel at pH7.0, with apparent mol.wt. 70000. 3. The enzyme was highly specific for the phosphorylated P-light chain of myosin, had pH optima at 6.5 and 8.0 and was not inhibited by NaF. 4. A Ca2+-sensitive ‘ATPase’ (adenosine triphosphatase) system consisting of myosin light-chain kinase, myosin light-chain phosphatase and the P-light chain is described. 5. Evidence is presented for a phosphoryl exchange between Pi, phosphorylated P-light chain and myosin light-chain phosphatase. 6. Heavy meromyosin prepared by chymotryptic digestion can be phosphorylated by myosin light-chain kinase. 7. The ATPase activities of myosin and heavy meromyosin, in the presence and absence of F-actin, were not significantly changed (+/- 10%) by phosphorylation of the P-light chain.

Molecular characterization of rat skeletal muscle myosin light chain kinase

1989 ◽  
Vol 256 (2) ◽  
pp. C399-C404 ◽  
Author(s):  
B. P. Herring ◽  
M. H. Nunnally ◽  
P. J. Gallagher ◽  
J. T. Stull
Keyword(s):  
Skeletal Muscle ◽  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Skeletal Muscles ◽  
Myosin Light Chain ◽  
Cardiac Tissue ◽  
Rat Skeletal Muscle ◽  
Skeletal Muscle Myosin ◽  
Slow Twitch ◽  
Muscle Myosin

A 1.85-kilobase (kb) cDNA has been isolated that encodes the catalytic and calmodulin binding domains of rat skeletal muscle myosin light chain kinase. The cDNA hybridized to a 3.3-kb RNA present in fast- and slow-twitch skeletal muscles. The reported enzymatic activity (3-fold greater in fast- than slow-twitch skeletal muscles) reflects the relative abundance of this RNA in the two types of skeletal muscle. No hybridization of the cDNA was detected to RNA isolated from smooth or nonmuscle tissues. The clone cross hybridized to a 2.2-kb RNA present in cardiac tissue. Ribonuclease protection analysis of skeletal and cardiac muscle RNA revealed major differences in the two hybridizing RNAs. Thus rat skeletal muscle contains a single myosin light chain kinase isoform, which is distinct from the cardiac, smooth, and nonmuscle forms.

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