Fragmentation of proteins in cartilage treated with IL-1. Specific cleavage of type IX collagen by MMP-13 releases the NC4 domain.
Degradation of bovine nasal cartilage induced by interleukin-1 (IL-1) was used to study catabolic events in the tissue over 16 days. Culture medium was fractionated by two-dimensional electrophoresis (isoelectric focusing and SDS-PAGE). Identification of components by peptide mass fingerprinting revealed released fragments representing the NC4 domain of the type IX collagen {alpha}1 chain at days
