- Natural bovine osteogenin and recombinant human bone morphogenetic protein-2B are equipotent in the maintenance of proteoglycans in bovine articular cartilage explant cultures. Luyten, F.P., Yu, Y.M., Yanagishita, M., Vukicevic, S., Hammonds, R.G., Reddi, A.H. J. Biol. Chem. (1992)