title: Identification of a type V collagen-degrading enzyme from human sputum.
abstract: An enzyme capable of degrading type V collagen was found in the sputum of patients with chronic obstructive pulmonary disease (COPD). This enzyme was found in a latent form and was activated by 4-aminophenylmercuric acetate (APMA). Molecular sieve chromatography on Ultrogel AcA-34 and affinity chromatography on type V collagen-Sepharose were successful in separating type V from type I collagenolytic activity. The enzyme became active after affinity chromatography and no longer required activation with APMA to manifest activity. It was found to be a metalloproteinase by virtue of its inhibition by ethylene-diaminetetraacetic acid and phenanthroline but not by phenylmethanesulfonyl fluoride or N-ethylmaleimide. Because degradation of matrix proteins is felt to be important in the pathogenesis of COPD, it is possible that the selective degradation of type V collagen by this enzyme may play a role in the development of COPD.
mesh_terms: D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D003094:Collagen / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000032:analysis*; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000201:enzymology; D008666:Metalloendopeptidases; D003012:Microbial Collagenase / Q000032:analysis*; D010662:Phenylmercuric Acetate / Q000031:analogs & derivatives / Q000494:pharmacology; D013183:Sputum / Q000201:enzymology*
chemical_list: C010024:4-aminophenylmercuriacetate; D003094:Collagen; D010450:Endopeptidases; D008666:Metalloendopeptidases; D003012:Microbial Collagenase; D010662:Phenylmercuric Acetate