title: IGFBP-3 and IGFBP-5 associate with the cell binding domain (CBD) of fibronectin.
abstract: We have used Surface Plasmon Resonance (SPR) - based biosensor technology to investigate the interaction of the six high affinity insulin-like growth factor binding proteins (IGFBP 1-6) with the cell binding domain (CBD) of fibronectin. Using a biotinylated derivative of the ninth and tenth TypeIII domains of FN ((9-10)FNIII), we show that IGFBP-3 and -5 bind to FN-CBD. We show that this binding is inhibited by IGF-I and that, for IGFBP-5, binding occurs through the C-terminal heparin binding domain of the protein. Using site-directed mutagenesis of (9-10)FNIII, we show both the "synergy" and RGD sites within these FN domains are required for maximum binding of both IGFBPs. We discuss the possible biological consequences of our results.
authors.affiliation: Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom. J.Beattie@leeds.ac.uk
authors.forename: James
authors.initials: J
authors.lastname: Beattie
authors.forename: Michaela
authors.initials: M
authors.lastname: Kreiner
authors.forename: Gordon J
authors.initials: GJ
authors.lastname: Allan
authors.forename: David J
authors.initials: DJ
authors.lastname: Flint
authors.forename: Diana
authors.initials: D
authors.lastname: Domingues
authors.forename: Christopher F
authors.initials: CF
authors.lastname: van der Walle
mesh_terms: D000818:Animals; D005353:Fibronectins / Q000378:metabolism*; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000235:genetics / Q000378:metabolism*; D018975:Insulin-Like Growth Factor Binding Protein 5 / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D017434:Protein Structure, Tertiary / Q000235:genetics; D020349:Surface Plasmon Resonance
chemical_list: D005353:Fibronectins; D018972:Insulin-Like Growth Factor Binding Protein 3; D018975:Insulin-Like Growth Factor Binding Protein 5