[Purification and properties of a growth factor from human bone matrix]

A growth factor was isolated from demineralized human bone-matrix and purified approximately 2,300-fold with 5.6% yield by the procedures of acetone treatment, Blue-A matrix gel chromatography, Sephadex G-75 gel filtration and Mono-Q fast protein liquid chromatography. The final preparation was homogeneous and a single polypeptide of 18,000 daltons as judged by SDS-polyacrylamide gel electrophoresis. The purified growth factor stimulated DNA synthesis in embryonic chick osteoblast in a dose-dependent manner and was saturated at the concentration of 4 ng/ml. By comparing various properties of the final preparation with those of other growth factors derived from bone, it appears to be a novel growth factor, and may be one of the important local regulators of bone remodeling.