Human 92- and 72-kilodalton type IV collagenases are elastases.

摘要: Elastin is critical to the structural integrity of a variety connective tissues. Only select group enzymes has thus far been identified capable cleaving insoluble elastin. Recently, we observed that human alveolar macrophages secrete elastase activity largely inhibited by tissue inhibitor metalloproteinases (TIMP). This finding suggested one or more released activity. Accordingly, tested pure interstitial collagenase, stromelysin, 92-kDa type IV and 72-kDa collagenase for elastolytic using kappa-elastin zymography 3H-labeled The 92- collagenases were found be in both assay systems. A recombinant preparation with gelatinolytic was also elastolytic. Organomercurial activation essential detect native enhanced enzyme. On molar basis approximately 30% as active leukocyte solubilizing Exogenously added TIMP significant excess abolished collagenases. Stromelysin showed no activity, although catalytically against susceptible substrates. Conditioned media from cultures mononuclear phagocytes containing enzyme produced distinct zone lysis zymograms at this molecular mass. These results definitively extend spectrum proteinases suggest enzymatic certain cell types such macrophages.