title: Purification of a type V collagen degrading metalloproteinase from rabbit alveolar macrophages.
abstract: A proteinase capable of degrading the helical region of native human type V collagen was identified in serum-free culture medium from "in vivo-activated" rabbit alveolar macrophages. This enzyme was purified to homogeneity using a combination of gel-filtration, ion-exchange and affinity chromatography. Analysis of the purified material by gel electrophoresis revealed a single broad band with relative molecular mass of 82,000 daltons Enzyme activity was eluted from the gel in a region corresponding to the stained band. The protein band was also found to stain positively using the periodic acid-Schiff technique indicating that it was glycosylated. Amino acid analysis revealed a composition rich in acidic residues. The enzyme cleaved type V collagen into three large molecular weight doublets consistent with two cleavage sites within the helix but was inactive against native type I collagen. However, when type I or type V collagen was heat-denatured, the enzyme degraded the alpha chains to small molecular weight peptides.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002478:Cells, Cultured; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003094:Collagen / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000032:analysis / Q000302:isolation & purification*; D018093:Gelatinases; D008264:Macrophages / Q000201:enzymology*; D008666:Metalloendopeptidases; D010434:Pepsin A / Q000378:metabolism; D011650:Pulmonary Alveoli / Q000166:cytology / Q000201:enzymology*; D011817:Rabbits
chemical_list: D000596:Amino Acids; D003094:Collagen; D010450:Endopeptidases; D010434:Pepsin A; D018093:Gelatinases; D008666:Metalloendopeptidases