Linked Life Data

2044770

Source:http://linkedlifedata.com/resource/pubmed/id/2044770

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1991-7-17
pubmed:abstractText
The phosphopeptide Ser (P)-Ser(P)-Ser-(P)-Glu-Glu-Ser22-Ile-Thr, reproducing the 17-24 segment of beta-casein A2 including the seryl residue (Ser-22) which is targeted by casein kinase-1 was synthesized and used as model substrate for this enzyme. Its phosphorylation efficiency is actually higher than that of intact beta-casein (similar Vmax and 14 microM Km). Conversely the fully dephosphorylated peptide SSSEESIT is not affected by CK-1 to any detectable extent and its glutamyl derivative EEEEESIT displays a more than 50-fold higher Km and a 5-fold lower Vmax as compared to the parent phosphopeptide. The relevance of the individual phosphoseryl residues has been assessed by comparing the phosphorylation efficiencies of the phosphopeptides EESpEESIT, ESpEEESIT and SpEEEESIT: while the first is a substrate almost as good as the tris Ser (P)-peptide (Km = 62 microM), and the third one is almost as poor as EEEEESIT (Km = 1.55 mM), ESpEEESIT displays a intermediate efficiency (Km = 277 microM). These data in conjunction with the finding that the phosphopentapeptide Ser(P)-Ser(P)-Ser(P)-Ser-Ser(P), but neither Ser(P)-Ser(P)-Ser-Ser(P) nor Ser-Ser(P)-Ser(P)-Glu-Glu and Ser-Ala-Ala-Ser(P)-Ser(P), is readily phosphorylated by CK-1, support the concept that CK-1 is a phosphate directed protein kinase recognizing the Ser(P)-X-X-Ser-X and, less efficiently, the Ser(P)-X-X-X-Ser-X motifs.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0014-5793
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
283
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
303-6
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
A synthetic beta-casein phosphopeptide and analogues as model substrates for casein kinase-1, a ubiquitous, phosphate directed protein kinase.
pubmed:affiliation
Dipartimento di Chimica Biologica, Università di Padova, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't