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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
17
|
| pubmed:dateCreated |
1993-7-13
|
| pubmed:abstractText |
Smooth muscle myosin light chain kinase (MLCK) is stable in the presence of Ca2+/calmodulin and does not undergo inactivation as reported for skeletal muscle MLCK (Kennelly, P.J., Starovasnik, M.A., Edelman, A.M., and Krebs, E.G. (1990) J. Biol. Chem. 265, 1742-1749). The 61-kDa tryptic fragment of smMLCK-(283-779) with the pseudosubstrate/calmodulin binding sequence deleted undergoes rapid inactivation (t1/2 = 5 min at 25 degrees C). Thermal inactivation renders the 61-kDa fragment more susceptible to cleavage by trypsin. The pseudosubstrate sequence, smMLCK-(787-807) prevents inactivation with high potency (half-maximal protective concentration, PC0.5 = 102 +/- 9 nM). The hexapeptide smMLCK-(797-802), Arg-Arg-Lys-Trp800-Gln-Lys, protected with a similar potency (PC0.5 = 73 +/- 14 nM). The four basic residues as well as Trp were important for maintaining protection by the hexapeptide smMLCK-(797-802). Substitution of Trp800 with Ala or Leu increased the PC0.5 to 500 nM. However, substitution of both aromatic residues Tyr794 and Trp800 in the longer pseudosubstrate peptide-(787-807) had little effect, indicating that with the longer peptide other multiple interactions were sufficient to stabilize the enzyme. The peptide substrate MLC-(11-23) A14,15 was also protective (PC0.5 = 380 nM) as was Mg(2+)-ATP, Mg(2+)-ADP, and Mg2+ plus adenosine. The results demonstrate that the sequence extending from 787-815 encoding the previously identified overlapping pseudosubstrate and calmodulin binding sequences also contains residues that are essential for maintaining thermal stability but these exhibit distinct structure/function relationships.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Calmodulin,
http://linkedlifedata.com/resource/pubmed/chemical/Myosin-Light-Chain Kinase,
http://linkedlifedata.com/resource/pubmed/chemical/Peptide Fragments,
http://linkedlifedata.com/resource/pubmed/chemical/Peptides,
http://linkedlifedata.com/resource/pubmed/chemical/Trypsin
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Jun
|
| pubmed:issn |
0021-9258
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
15
|
| pubmed:volume |
268
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
12484-91
|
| pubmed:dateRevised |
2009-11-19
|
| pubmed:meshHeading |
pubmed-meshheading:8509388-Amino Acid Sequence,
pubmed-meshheading:8509388-Animals,
pubmed-meshheading:8509388-Binding Sites,
pubmed-meshheading:8509388-Calmodulin,
pubmed-meshheading:8509388-Chickens,
pubmed-meshheading:8509388-Chromatography, Affinity,
pubmed-meshheading:8509388-Enzyme Stability,
pubmed-meshheading:8509388-Gizzard,
pubmed-meshheading:8509388-Kinetics,
pubmed-meshheading:8509388-Molecular Sequence Data,
pubmed-meshheading:8509388-Muscle, Smooth,
pubmed-meshheading:8509388-Muscles,
pubmed-meshheading:8509388-Myosin-Light-Chain Kinase,
pubmed-meshheading:8509388-Peptide Fragments,
pubmed-meshheading:8509388-Peptides,
pubmed-meshheading:8509388-Sequence Homology, Amino Acid,
pubmed-meshheading:8509388-Substrate Specificity,
pubmed-meshheading:8509388-Thermodynamics,
pubmed-meshheading:8509388-Time Factors,
pubmed-meshheading:8509388-Trypsin
|
| pubmed:year |
1993
|
| pubmed:articleTitle |
Role of the pseudosubstrate sequence in smooth muscle myosin light chain kinase thermal stability.
|
| pubmed:affiliation |
St. Vincent's Institute of Medical Research, Fitzroy Victoria, Australia.
|
| pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, Non-U.S. Gov't
|