title: Characterization of specific insulin-like growth factor (IGF)-I and IGF-II receptors on cultured rabbit articular chondrocyte membranes.
abstract: The interaction of insulin-like growth factor (IGF)-I and IGF-II with specific type-I and -II receptor sites on rabbit articular chondrocyte membranes was studied. With labelled IGF-I as tracer, half-maximal displacement of the label was obtained with 1.4 ng IGF-I/ml and 22 ng IGF-II/ml. Using IGF-II as labelled peptide. 16 ng unlabelled IGF-II/ml and 200 ng IGF-I/ml were needed to inhibit the binding by 50%. Covalent cross-linking experiments revealed the presence of typical type-I (Mr 130,000 under reducing conditions) and type-II (Mr 260,000) receptor sites. In addition, with 125I-labelled IGF-II a very intense labelled band appeared at Mr greater than 300,000. This band was not found in mouse liver membranes and human placental membranes.
authors.affiliation: University Hospital for Children and Youth, 'Het Wilhelmina Kinderziekenhuis', State University of Utrecht, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Jansen
authors.forename: S C
authors.initials: SC
authors.lastname: van Buul-Offers
authors.forename: C M
authors.initials: CM
authors.lastname: Hoogerbrugge
authors.forename: T L
authors.initials: TL
authors.lastname: de Poorter
authors.forename: M T
authors.initials: MT
authors.lastname: Corvol
authors.forename: J L
authors.initials: JL
authors.lastname: Van den Brande
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002358:Cartilage, Articular / Q000032:analysis*; D002462:Cell Membrane / Q000032:analysis; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D008970:Molecular Weight; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000302:isolation & purification*; D017451:Receptors, Somatomedin
chemical_list: D011956:Receptors, Cell Surface; D017451:Receptors, Somatomedin; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II