Purification and characterization of two cartilage-inducing factors from bovine demineralized bone.
Two naturally occurring peptides that induce chondrogenesis in culture have been purified to apparent homogeneity. These cartilage-inducing factors (CIF-A and CIF-B) were isolated from bovine demineralized bone by dissociative extraction, gel filtration, cation-exchange chromatography, and reversed-phase HPLC. CIF-A and CIF-B at concentrations of 1-10 ng/ml each induce embryonic rat mesenchymal cells in culture to assume a cartilage morphology and synthesize cartilage-specific proteoglycan and type II collagen. The amino acid compositions of CIF-A and CIF-B are similar but not identical. Both factors have an apparent Mr of 26,000, as determined by NaDodSO4/PAGE. In the presence of 2-mercaptoethanol, both are converted to species of about one-half that Mr, indicating that they are dimers of identical or very similar chains.
D000818:Animals; D001842:Bone and Bones / Q000032:analysis*; D002356:Cartilage / Q000254:growth & development*; D002417:Cattle; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis; D006133:Growth Substances / Q000302:isolation & purification*; D011506:Proteins / Q000302:isolation & purification* / Q000494:pharmacology; D011509:Proteoglycans / Q000096:biosynthesis; D051381:Rats
D006133:Growth Substances; D011506:Proteins; D011509:Proteoglycans; D003094:Collagen