Collagenase-like peptidase activity in serum from patients with rheumatoid arthritis

The activities of collagenase-like peptidase, estimated by using (succinyl-Gly-Pro-Leu-Gly-Pro-Leu-Gly-Pro)-4-methylcoumaryl-7-amide as substrate, and of dipeptidyl-aminopeptidase IV were decreased in the sera from patients with rheumatoid arthritis. Both enzymes bring about the degradation of peptides derived from collagen. A significant positive correlation was observed between the activities of the two serum peptidases.