Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
23
pubmed:dateCreated
1985-1-10
pubmed:abstractText
The hexapeptides AcSer-Glu-Glu-Glu-Val-Glu and Ser-Glu-Glu-Glu-Glu-Glu, reminiscent of the sites phosphorylated by type-2 casein kinase TS in troponin T and glycogen synthase, respectively, have been synthesized and tested as phosphorylatable substrates for casein kinase TS as well as for other protein kinases. Both peptides are readily phosphorylated by casein kinase TS but not, to any detectable extent, by either cAMP-dependent protein kinase or phosphorylase kinase. Phosphorylation by type-1 casein kinase S was almost negligible. On the other hand the hexapeptide Ser-Glu-Glu-Glu-Ala-Ala is phosphorylated much more slowly and the hexapeptide Ser-Glu-Glu-Ala-Ala-Ala is almost unaffected by casein kinase TS. While the Vmax values of casein kinase TS with the acidic hexapeptides are comparable to those obtained with the corresponding protein substrates, the apparent Km values for the peptides are about two orders of magnitude higher than those for the protein substrates. The heptapeptide Arg-Ser-Glu-Glu-Glu-Val-Glu is a very poor substrate of casein kinase TS in comparison with the corresponding hexapeptide lacking the N-terminal Arg; it is, however, a competitive inhibitor toward the protein substrates, exhibiting a Ki similar to those of Ser-Glu-Glu-Glu-Glu-Glu and (Glu)5 which, in turn, are one order of magnitude higher than that of (Glu)10. It is concluded that the minimum structural requirement of type-2 casein kinases consists of a phosphorylatable residue followed by an acidic cluster, whose length is critical for the binding to the enzyme. Additional residues on the N-terminal side are not required, but their nature can influence the transphosphorylation reaction considerably.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
259
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14576-9
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Synthetic peptides including acidic clusters as substrates and inhibitors of rat liver casein kinase TS (type-2).
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't