High yield isolation of BMP-2 from bone and in vivo activity of a combination of BMP-2/TGF-β1.

A high-yield purification procedure for protein fractions derived from porcine bone matrix extracts is described, which has a high abundance of bone morphogenetic protein-2 (BMP-2). Naturally derived pBMP-2, ~5 μg per kilogram of porcine bone matrix, was isolated by using a 300 kDa membrane before chromatographic processing on heparin affinity media. The elution of pBMP-2 and transforming growth factor-β(1) (TGF-β(1)) revealed morphogen peaks that were unresolved on Prosep(®) medium, but resolved on hydroxyapatite medium. Antagonism was observed in animal studies when the two proteins were combined in specific doses. The TGF-β(1) fraction alone was not active in the rodent heterotopic in vivo bioassay, confirming previously obtained results.