title: Chemical and biological characterization of low-molecular-weight human skeletal growth factor.
abstract: Skeletal growth factor (SGF) activity was extracted from human bone matrix by demineralization and purified under dissociative conditions using hydroxyapatite, HPLC gel-filtration and HPLC reverse-phase chromatography. Human SGF thus purified was characterized chemically and biologically. Purified human SGF stimulated chick embryo bone cell proliferation at picomolar concentrations (half maximum at 2-3 ng/ml) and had little or no activity on other cell types tested (mouse 3T3 and normal rat kidney fibroblasts, embryonic chick intestinal and human placental cells). Human SGF did not displace 125I-labeled epidermal growth factor binding to normal rat kidney cells and did not stimulate normal rat kidney cell colony formation in soft agar. Human SGF activity was sensitive to trypsin, chymotrypsin, papain, dithiothreitol and performic acid but was resistant to heat (upto 70 degrees C), pH (3-10), cyanogen bromide, alkaline phosphatase and neuraminidase and did not bind jack bean concanavalin A or kidney bean lectin. From our chemical and biological studies it appears that human SGF is different from other known polypeptide growth factors: epidermal growth factor, fibroblast growth factor, insulin, insulin-like growth factor-I, platelet-derived growth factor and transforming growth factor.
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002642:Chick Embryo; D004815:Epidermal Growth Factor / Q000494:pharmacology; D066246:ErbB Receptors / Q000378:metabolism; D005346:Fibroblast Growth Factors / Q000032:analysis; D006133:Growth Substances / Q000032:analysis / Q000494:pharmacology; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D007335:Insulin-Like Growth Factor II; D051379:Mice; D008934:Mitogens; D009928:Organ Specificity; D010455:Peptides / Q000494:pharmacology; D010982:Platelet-Derived Growth Factor / Q000032:analysis; D011506:Proteins / Q000032:analysis* / Q000494:pharmacology; D051381:Rats; D013045:Species Specificity; D015291:Transforming Growth Factors
chemical_list: D006133:Growth Substances; C035170:IGF2 protein, human; D008934:Mitogens; D010455:Peptides; D010982:Platelet-Derived Growth Factor; D011506:Proteins; D005346:Fibroblast Growth Factors; D004815:Epidermal Growth Factor; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D015291:Transforming Growth Factors; D066246:ErbB Receptors