Cleavage of cartilage proteoglycan between G1 and G2 domains by stromelysins

Abstract

Normal and pathological turnover of proteoglycans in articular cartilage involves its cleavage close to the N-terminal G1 domain responsible for aggregation, A fragment containing G1 and G2 N-terminal domains of pig cartilage proteoglycans was therefore used as a substrate to investigate its degradation by the metalloproteinase stromelysin and related recombinant stromelysin enzymes. The stromelysins produced an apparent single cleavage yielding a G1 fragment of 56 kDa and a G2 fragment of 110 kDa. Rabbit bone stromelysin was much more active against the G1-G2 fragment and against proteoglycan aggregates than recombinant human stromelysin-1 and stromelysin-2. All metalloproteinase preparatio..