Fig. 1

Matrix metalloproteinase (MMP) and aggrecanase cleavage sites in bovine aggrecan. Aggrecanase and MMP cleavage sites of bovine aggrecan were identified by amino acid sequence comparison with human aggrecan sequence by Western blot analysis of bovine aggrecan (see Additional file 1: Figure S1) and as previously described [38, 47, 54,55,56]. Bovine aggrecan fragments, with molecular mass in kilodaltons in brackets, detected in explant cultures are shown. Using GVEDI(L)SG(R/V)L as a consensus sequence for MMP digestion resulted in 14 potential cleavage sites for MMP in the bovine CS1 region. The amino acid numberings are based on the full-length bovine aggrecan amino acid sequence starting with the N-terminal ¹MTTL and finishing with the C-terminal STAH²³⁶⁴ (National Center for Biotechnology Information accession number P13608). IGD Interglobular domain, KS Keratan sulfate region, CS Chondroitin sulfate region, G1–G3, Globular domains 1–3