title: Characterization and serum inhibition of neutral collagenase from cultured dog gingival tissue.
abstract: 1. Explants of dog gingiva, maintained in culture for 9 days in the absence of serum, released a collagenase (EC 3.4.24.3) into the medium. The yield of active enzyme reached a maximum after 5-8 days with concomitant release of collagen degradation products from the explants. 2. The enzyme attacked undenatured collagen in solution at 25 degrees C resulting in a 58% loss of specific viscosity and producing the two characteristic products TCA(3/4) and TCB(1/4). Electron microscopy of segment-long-spacing crystallites of these reaction products showed the cleavage locus of the collagen molecule at interband 40. 3. Optimal enzyme activity was observed over the pH range 7.5-8.5 and a molecular weight of approximately 35,000 was derived from gel filtration studies. EDTA, 1,10-phenanthroline, cysteine and dithiothreitol all inhibited collagenase activity. Proteoglycan derived from porcine and human cartilage did not inhibit the enzyme. 4. The enzyme was inhibited by the dog serum proteins alpha2-macroglobulin and a smaller component of molecular weight approximately 40,000. This small component was purified by column chromatography utilising Sephadex G-200, DEAE A-50, and G-100 (superfine grade). Agarose electrophoresis of the purified component showed it to represent a beta-serum protein. alpha1-Antitrypsin did not inhibit the enzyme. 5. The physiological importance of the natural serum inhibitors and gingival collagenase are discussed in relation to latent enzyme and periodontal disease.
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000502:physiology; D003470:Culture Media; D004285:Dogs; D005881:Gingiva / Q000201:enzymology*; D007700:Kinetics; D003012:Microbial Collagenase / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D009924:Organ Culture Techniques; D013997:Time Factors; D000511:alpha-Macroglobulins / Q000502:physiology
chemical_list: D001798:Blood Proteins; D003470:Culture Media; D000511:alpha-Macroglobulins; D003012:Microbial Collagenase