Identification and Characterization of Cellular Binding Proteins (Receptors) for Recombinant Human Bone Morphogenetic Protein 2B, an Initiator of Bone Differentiation Cascade

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 88; no. 8; pp. 3397 - 3401
• Main Authors: Paralkar, Vishwas M., Hammonds, R. Glenn, Reddi, A. H.
• Format: Journal Article
• Language: English
• Published: Washington, DC National Academy of Sciences of the United States of America 15.04.1991; National Acad Sciences
• Subjects: 3T3 cells; 550601 - Medicine- Unsealed Radionuclides in Diagnostics; Affinity Labels; ANIMAL TISSUES; ANIMALS; BETA DECAY RADIOISOTOPES; Biological and medical sciences; BODY; Bone and Bones - cytology; Bone and Bones - metabolism; bone growth; Bone Morphogenetic Proteins; BONE TISSUES; Bones; Carrier proteins; CELL DIFFERENTIATION; Cell Line; Cell receptors; Cell structures and functions; Cells; CHEMICAL REACTIONS; CONNECTIVE TISSUE; Cross-Linking Reagents; Crosslinking; DAYS LIVING RADIOISOTOPES; DNA - biosynthesis; ELECTRON CAPTURE RADIOISOTOPES; ELECTROPHORESIS; Epithelial cells; Fibroblast growth factors; Fundamental and applied biological sciences. Psychology; GROWTH; GROWTH FACTORS; HALOGENATION; Humans; INTERMEDIATE MASS NUCLEI; INTERNAL CONVERSION RADIOISOTOPES; IODINATION; IODINE 125; IODINE ISOTOPES; ISOTOPE APPLICATIONS; ISOTOPES; MAMMALS; MEMBRANE PROTEINS; Mice; Miscellaneous; MITOGENS; Molecular and cellular biology; Morphogenesis; NIH 3T3 cells; NUCLEI; ODD-EVEN NUCLEI; ORGANIC COMPOUNDS; Protein Binding; PROTEINS; Proteins - metabolism; RADIOISOTOPES; RADIOLOGY AND NUCLEAR MEDICINE; RADIORECEPTOR ASSAY; RATS; RECEPTORS; Receptors, Cell Surface - metabolism; Recombinant Proteins - metabolism; RODENTS; Room temperature; Temperature; Time Factors; TISSUES; TRACER TECHNIQUES; VERTEBRATES; Human; Binding protein; Cell line; Bone morphogenetic protein; Affinity labelling; Osteoblast; 3T3-Cell line; Binding site; Recombinant protein; Cell differentiation; Cell surface; Biological receptor
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.88.8.3397

Bone morphogenetic protein 2B (BMP 2B), is a heparin-binding bone differentiation factor that initiates endochondral bone formation in rats when implanted subcutaneously. The molecular mechanism of action of this differentiation factor is not known, and as a first step we have examined BMP 2B-responsive cells for the presence of specific cellular binding proteins. Using125I-labeled BMP 2B, specific high-affinity binding sites for recombinant human BMP 2B on MC3T3 E1 osteoblast-like cells as well as on NIH 3T3 fibroblasts were identified. Platelet-derived growth factor, insulin-like growth factor 1, basic fibroblast growth factor, epidermal growth factor, and transforming growth factor β did not compete for the binding of radiolabeled BMP 2B. The binding of BMP 2B is a time- and temperature-dependent process. Chemical crosslinking of radiolabeled BMP showed two components (apparent size, 200 and 70 kDa in MC3T3 E1 cells and 200 and 90 kDa in NIH 3T3 cells). A minor component at 60 kDa was also detected in both cell lines. Scatchard analysis of the binding data showed a high-affinity receptor with an apparent dissociation constant of 128 ± 40 pM in MC3T3 E1 cells. These data demonstrate specific, high-affinity cell-surface binding proteins for BMP 2B.