title: Identification of neutral proteases in human neutrophil granules that degrade articular cartilage proteoglycan.
abstract: Human polymorphonuclear neutrophil (PMN) granule extract (25 mug of protein) released 60 percent of the available 35SO4 from labeled rabbit articular cartilage in 0.5 hour at neutral pH. N-acetyl-L-alanyl-L-alanyl-L-prolyl-L-alanine choloromethyl ketone (NAcAAPACK), a specific elastase inhibitor, was only minimally effective against whole granule extract, and N-alpha-tosyl-L-lysine chloromethyl ketone, which inhibits trypsin but not elastase, was completely ineffective. Preparative disc-gel electrophoresis of PMN granule extract revealed two separate regions with independent activity against 35SO4-labeled cartilage. One region contained elastases and when tested alone, was completely inhibited by NAcAAPACK. The other contained lysozyme and two esterases active against N-acetyl-L-phenylalanine-alpha-naphthol. Purified lysozyme proved inactive, suggesting that the chymotrypsin-like esterases were responsible for proteoglycan degradation by this region of the gel.
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000378:metabolism*; D003594:Cytoplasmic Granules / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004950:Esterases / Q000302:isolation & purification; D006025:Glycosaminoglycans / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007659:Ketones / Q000494:pharmacology; D009504:Neutrophils / Q000201:enzymology*; D010196:Pancreatic Elastase / Q000302:isolation & purification; D010447:Peptide Hydrolases / Q000302:isolation & purification*; D011509:Proteoglycans / Q000378:metabolism*; D011817:Rabbits; D013462:Sulfur Radioisotopes; D014108:Tosylphenylalanyl Chloromethyl Ketone / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D006025:Glycosaminoglycans; D007659:Ketones; D011509:Proteoglycans; D013462:Sulfur Radioisotopes; D014108:Tosylphenylalanyl Chloromethyl Ketone; D004950:Esterases; D010447:Peptide Hydrolases; D010196:Pancreatic Elastase