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Direct activation of human neutrophil procollagenase by recombinant stromelysin.

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.

SUBMITTER: Knauper V

PROVIDER: S-EPMC1134920 | biostudies-other | 1993 Oct

REPOSITORIES: biostudies-other

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Stromelysin is an activator of procollagenase. A study with natural and recombinant enzymes.

Project description:The latent forms of stromelysin and collagenase from human gingival fibroblasts were purified to homogeneity. These latent proenzymes underwent serial small reductions in Mr upon activation by treatment with either 4-aminophenylmercuric acetate or trypsin. Similar shifts in Mr and activation kinetics were observed upon identical treatments of either recombinant prostromelysin or procollagenase. Prostromelysin showed a lag between activation and Mr fall, suggesting an initial activation by conformational change. Collagenase activity was enhanced up to 12-fold by either natural or recombinant stromelysin in the presence of trypsin or 4-aminophenylmercuric acetate. Stromelysin caused a further apparent decrease in the Mr of procollagenase. Since these important connective-tissue-degrading enzymes are usually co-ordinately produced by cells, a cascade mechanism is proposed in which collagenase is activated by stromelysin.

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Lipopolysaccharide-Stimulated Human Fetal Membranes Induce Neutrophil Activation and Release of Vital Neutrophil Extracellular Traps.

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Circulating Neutrophil Extracellular Traps and Neutrophil Activation Are Increased in Proportion to Disease Severity in Human Malaria.

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| S-EPMC1147066 | biostudies-other

Activation of human neutrophil gelatinase by endogenous serine proteinases.

Project description:The role of serine proteinases and oxidants in the activation of gelatinase released from human neutrophils was investigated. Gelatinase was measured by its ability to degrade both gelatin and native glomerular basement-membrane type IV collagen. When fMet-Leu-Phe or phorbol 12-myristate 13-acetate was used to stimulate the neutrophils, no gelatinase activity was measured in the absence of a mercurial activator, indicating that the enzyme was released entirely in latent form. However, when fMet-Leu-Phe-stimulated cells were treated with cytochalasin B, 50-70% of the maximal gelatinase activity was released. Activation was blocked by the serine-proteinase inhibitor phenylmethanesulphonyl fluoride and a specific inhibitor of neutrophil elastase, but was not affected by an inhibitor of cathepsin G. Addition of catalase or azide to prevent oxidative reactions did not affect activation of gelatinase under any conditions of stimulation, indicating that oxidants were not involved in activation. Our results imply that oxidative activation of gelatinase does not occur readily. However, neutrophil serine proteinases, particularly elastase, provide an alternative and apparently more efficient mechanism of activation.

| S-EPMC1148706 | biostudies-other

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