title: A synthetic peptide substrate specific for casein kinase I.
abstract: The synthetic peptide, Asp-Asp-Asp-Glu-Glu-Ser-Ile-Thr-Arg-Arg, derived from the phosphorylation site of casein kinase-1 (CK-1) in beta-casein A(2), is readily phosphorylated by CK-1, but not by casein kinase-2(CK-2), cyclic AMP-dependent protein kinase, protein kinase C, phosphorylase kinase and protein kinase FA. Phosphorylation by CK-1 occurs only at Ser-6, Thr-8 being unaffected. The Km for the peptide is higher (1 mM) than for beta-casein A(2) (40 microM), while the Vmax is quite comparable. This is the first synthetic peptide substrate for CK-1 described so far, and can be used for the rapid and specific estimation of CK-1 activity in crude extracts.
authors.affiliation: Faculteit Geneeskunde, Katholieke Universiteit te Leuven, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Agostinis
authors.forename: L A
authors.initials: LA
authors.lastname: Pinna
authors.forename: F
authors.initials: F
authors.lastname: Meggio
authors.forename: O
authors.initials: O
authors.lastname: Marin
authors.forename: J
authors.initials: J
authors.lastname: Goris
authors.forename: J R
authors.initials: JR
authors.lastname: Vandenheede
authors.forename: W
authors.initials: W
authors.lastname: Merlevede
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D047388:Casein Kinases; D008099:Liver / Q000201:enzymology; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D013379:Substrate Specificity
chemical_list: D009842:Oligopeptides; D011494:Protein Kinases; D047388:Casein Kinases