Abstract
Human neutrophil procollagenase was activated by incubation with recombinant active stromelysin. Activation was achieved by cleavage of the Gly78-Phe79 peptide bond at the end of the propeptide domain in a single-step activation mechanism. In addition, accelerated activation was achieved when N-terminally truncated, latent collagenase (with Phe49 as its N-terminal residue) was incubated with recombinant active stromelysin. Determination of the specific activity of recombinant-stromelysin-activated neutrophil collagenase with dinitrophenyl-octapeptide or type I collagen demonstrated the generation of high specific activity. The specific activity of stromelysin-activated enzyme was considerably higher than that of trypsin- or HgCl2-activated collagenase. Thus human neutrophil collagenase is superactivated, like the homologous fibroblast collagenase [Murphy, Cockett, Stephens, Smith and Docherty (1987) Biochem. J. 248, 265-268]. The occurrence of Phe79 at the N-terminus of the neutrophil collagenase seemed to be critical for superactivation, which is in agreement with data published by Suzuki, Enghild, Morodomi, Salvesen and Nagase [(1990) Biochemistry 29, 10261-10270] on fibroblast collagenase.