Solubilization and purification of bone morphogenetic protein (BMP) from Dunn osteosarcoma

The 4 M GuHCl soluble proteins of Dunn osteosarcoma were fractionated in two steps by means of CsCl density gradient centrifugation. Further purification of bone morphogenetic protein (BMP) was accomplished by molecular sieve techniques utilizing thin-channel diafiltration (Amicon), Sepharose CL-6B and Sephacryl S-200 gel filtration. Partially purified BMP fractions were analyzed by electrophoresis on 7.5% SDS polyacrylamide gel. The molecular weight of BMP active fractions ranges from 30,000 to a few thousand daltons. BMP may be one of the two proteins of MW of 12,500 and 16,000 daltons.