Identification of catabolin,a protein from synovium which induces degradation of cartilage in organ culture

Explants of porcine synovium produce a factor which causes degradation of the matrix of live cartilage in organ culture. Cartilage degradation was measured as release of glycosaminoglycan from explants of bovine nasal septum. Fractionation of synovial culture medium showed the factor to be a protein of 20,000 mol.wt. and iso-electric point pH = 4.6. The factor has been named catabolin.