title: Platelet-derived growth factor. Specific binding to target cells.
abstract: The binding of the human platelet-derived growth factor (PDGF) to Swiss mouse 3T3 cells have been investigated. The binding is specific and reversible. The dissociation constant is approximately 0.7 x 10(-9) M with approximately 400,000 binding sites/cell. Two forms of PDGF, PDGF I (Mr = 31,000) and PDGF II (Mr = 28,000), previously identified (Deuel, T. F., Huang, J. S., Proffitt, R. T., Baenziger, J. U., Chang, D., and Kennedy, B. B. (1981) J. Biol. Chem. 256, 8896-8899 and Deuel, T. F., Huang. J. S., Proffitt, R. T., Chang, D., and Kennedy, B. B. (1981) J. Supramol. Cell Biochem. 5 (Suppl.), 128) bind equally well to 3T3 cells. Polylysine and histone, but not cytochrome c, partially inhibit the binding of PDGF to 3T3 cells. Protamine sulfate blocks binding in a competitive manner and is capable of displacing PDGF previously bound to the cell surface. EDTA influenced neither the binding of PDGF to the cell surface nor the displacement of cell-bound PDGF. At 37 degrees C, PDGF bound to the cell surface is lost and iodotyrosine is released free into the supernatant, with each process having a t 1/2 of approximately 90 min. The binding activity of the putative PDGF receptor is markedly reduced by previous incubation with PDGF, thereby apparently regulating its activity in a manner similar to epidermal growth factor.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D006133:Growth Substances / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D051379:Mice; D008934:Mitogens / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism*; D010982:Platelet-Derived Growth Factor; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017479:Receptors, Platelet-Derived Growth Factor; D013696:Temperature
chemical_list: D006133:Growth Substances; D008934:Mitogens; D010455:Peptides; D010982:Platelet-Derived Growth Factor; D011956:Receptors, Cell Surface; D017479:Receptors, Platelet-Derived Growth Factor