Purification and characterization of bone morphogenetic protein derived from bovine bone matrix

Bone morphogenetic protein (BMP) was extracted from bovine bone matrix and purified. The 6M guanidine-HCL soluble fraction and the final purified substance were bioassayed by implantation of about 3 mg into the thigh muscles of C3H strain mice. These specimens induced new bone in three weeks when implanted into muscle pouches of the C3H mouse. The final fraction purified by liquid chromatography (fraction III) was shown to be homogeneous by sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis (SDS-PAGE). The molecular weight of the bovine bone matrix-derived BMP was estimated to be about 14-18 kDa in MW. The main components correspond to a MW of 18 kDa and 14 kDa when they are compared with the mobilities of standard proteins. These were invariably present in fractions with osteoinductive activity.