scholarly journals Studies on rat parotid-cell actomyosin

1984 ◽  
Vol 220 (1) ◽  
pp. 291-299 ◽  
Author(s):  
T Kealey ◽  
P J Randle
Keyword(s):  
Affinity Chromatography ◽  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Bovine Brain ◽  
Cell Protein ◽  
Collagenase Digestion ◽  
Heat Treated ◽  
Parotid Cells ◽  
Rat Parotid

Actomyosin was partially purified from rat parotid cells dispersed by collagenase digestion and found to possess different solubility characteristics from that from (undispersed) rat parotid tissue. This is attributed to the decrease in vascular contamination effected by the isolation of parotid cells, yielding a non-muscle actomyosin [Adelstein, Conti, Johnson, Pastan & Pollard (1972) Proc. Natl. Acad. Sci. U.S.A. 69, 3693-3697]. Myosin light-chain kinase was partially purified from dispersed rat parotid cells by calmodulin affinity chromatography and shown to be activated by Ca2+-calmodulin. The calmodulin content of dispersed rat parotid cells was shown to be 6.50 +/- 0.59 ng of calmodulin/micrograms of rat parotid-cell protein (mean +/- S.E.M.), as determined by the activation of purified bovine brain phosphodiesterase by heat-treated extracts of dispersed rat parotid cells.

Immunocytochemical localization of 155 kDa myosin light chain kinase and myosin heavy chain in bovine brain

1995 ◽  
Vol 682 (1-2) ◽  
pp. 212-214 ◽  
Author(s):  
Hiroyuki Shimada ◽  
Teruo Shimizu ◽  
Hideto Kuwayama ◽  
Masashi Suzuki ◽  
Ryozo Nagai ◽  
...  
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Bovine Brain ◽  
Immunocytochemical Localization

scholarly journals Effect of wortmannin, a specific inhibitor of myosin light chain kinase, on amylase release in rat parotid acinar cells.

1993 ◽  
Vol 61 ◽  
pp. 325
Author(s):  
Kaede Kubota ◽  
Takashi Sakurai ◽  
Toshiko Yamazawa ◽  
Masamitsu Iino ◽  
Satoshi Nakanishi ◽  
...  
Keyword(s):  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Specific Inhibitor ◽  
Acinar Cells ◽  
Amylase Release ◽  
Parotid Acinar Cells ◽  
Rat Parotid

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.

scholarly journals Purification, characterization and substrate specificity of calmodulin-dependent myosin light-chain kinase from bovine brain

1987 ◽  
Vol 247 (3) ◽  
pp. 747-756 ◽  
Author(s):  
D C Bartelt ◽  
S Moroney ◽  
D J Wolff
Keyword(s):  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Protein Band ◽  
Bovine Brain ◽  
Major Protein ◽  
Dependent Manner ◽  
Major Protein Band

A substrate-specific calmodulin-dependent myosin light-chain kinase (MLCK) was purified 45,000-fold to near homogeneity from bovine brain in 12% yield. Bovine brain MLCK phosphorylates a serine residue in the isolated turkey gizzard myosin light chain (MLC), with a specific activity of 1.8 mumol/min per mg of enzyme. The regulatory MLC present in intact gizzard myosin is also phosphorylated by the enzyme. The Mr-19,000 rabbit skeletal-muscle MLC is a substrate; however, the rate of its phosphorylation is at best 30% of that obtained with turkey gizzard MLC. Phosphorylation of all other protein substrates tested is less than 1% of that observed with gizzard MLC as substrate. SDS/polyacrylamide-gel electrophoresis of purified MLCK reveals the presence of a major protein band with an apparent Mr of 152000, which is capable of binding 125I-calmodulin in a Ca2+-dependent manner. Phosphorylation of MLCK by the catalytic subunit of cyclic-AMP-dependent protein kinase results in the incorporation of phosphate into the Mr-152,000 protein band and a marked decrease in the affinity of MLCK for calmodulin. The presence of Ca2+ and calmodulin inhibits the phosphorylation of the enzyme. Bovine brain MLCK appears similar to MLCKs isolated from platelets and various forms of muscle.

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