DIRECT ACTIVATION OF HUMAN NEUTROPHIL PROCOLLAGENASE BY RECOMBINANT STROMELYSIN

Human neutrophil procollagenase was activated by incubation with recom binant active stromelysin. Activation was achieved by cleavage of the Gly78-Phe79 peptide bond at the end of the propeptide domain in a sing le-step activation mechanism. In addition, accelerated activation was achieved when N-terminally truncated, latent collagenase (with Phe49 a s its N-terminal residue) was incubated with recombinant active strome lysin. Determination of the specific activity of recombinant-stromelys in-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 considerabl y higher than that of trypsin- or HgCl2-activated collagenase. Thus hu man neutrophil collagenase is superactivated, like the homologous fibr oblast collagenase [Murphy, Cockett, Stephens, Smith and Docherty (198 7) Biochem. J. 248, 265-268]. The occurrence of Phe79 at the N-terminu s of the neutrophil collagenase seemed to be critical for superactivat ion, which is in agreement with data published Suzuki. Enghild, Morodo mi, Salvesen and Nagase [(1990) Biochemistry 29. 10261-10270] on fibro blast collagenase.