title: Membrane binding characteristics of two forms of transforming growth factor-beta.
abstract: Cartilage-inducing factors A and B (CIF-A and CIF-B) from bovine bone have recently been identified as transforming growth factor-beta (TGF-beta) (Seyedin, S.M., Thompson, A. Y., Bentz, H., Rosen, D. M., McPherson, J. M., Conti, A., Siegel, N. R., Galluppi, G. R., and Piez, K. A. (1986) J. Biol. Chem., 261, 5693-5695) and a unique protein homologous to TGF-beta (Seyedin S. M., Segarini, P. R., Rosen, D. M., Thompson, A. Y., Bentz, H., and Graycar, J. (1987) J. Biol. Chem., 262, 1946-1949), respectively. Although the biological activities of TGF-beta and CIF-B are similar, the divergence of CIF-B from the highly conserved amino acid sequence of TGF-beta prompted an investigation of its receptor binding properties. Three classes of cell surface binding components were identified. Class A has exclusive affinity for TGF-beta; class B has greater affinity for CIF-B; and class C has equal affinity for both proteins. A high molecular weight component, the predominant binding species, was further characterized and shown to consist of two components that are either class B or class C. The differential binding properties of TGF-beta and CIF-B to cell surface components suggest that there are biological activities unique to each of the proteins.
mesh_terms: D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D006031:Glycosylation; D008970:Molecular Weight; D010455:Peptides / Q000378:metabolism* / Q000494:pharmacology; D011487:Protein Conformation; D011956:Receptors, Cell Surface / Q000378:metabolism*; D018125:Receptors, Transforming Growth Factor beta; D015291:Transforming Growth Factors
chemical_list: D010455:Peptides; D011956:Receptors, Cell Surface; D018125:Receptors, Transforming Growth Factor beta; D015291:Transforming Growth Factors