title: Some properties of neutral proteinases from lysosomes of rabbit polymorphonuclear leucocytes.
abstract: Neutral proteinases capable of degrading proteoglycan were found in lysosomes of rabbit polymorphonuclear leucocytes extracted with 0 . 01 M citric acid. Esterase activity against an elastase substrate was also present but chymotrypsin- and trypsin-like activities were not detected; azocasein-degrading activity was poor. Proteoglycanase activity was stimulated by high concentrations of salts (0 . 2 M KCl) and divalent cations (Ca, Mg, Mn, Zn) but was inhibited by Cu++. Elastase activity was also stimulated by high ionic strength buffers and KCl, but not as much by divalent cations, and was inhibited by Cu++. Proteoglycanase in crude extracts was inhibited by EDTA, phenylmethanesulphonylfluoride (Pms-F), cell cytosol, alpha 1-antitrypsin, gold thiomalate and N-acetyl-di-L-alanyl-L-propyl-L-valine chloromethyl ketone (AAAPVCK). Partial inhibition by N-alpha-p-tosyl-L-lysine chloromethyl ketone (TLCK) and L-l-tosylamide-2-phenylethyl chloromethyl ketone (TPCK) occurred. Elastase adsorbed to CM-cellulose and was eluted by 0 . 6-0 . 7 M NaCl; a metallo-proteinase failed to adsorb completely but was retarded by the CM-cellulose. Isoelectric focusing showed that the major proteinases had pI's of 5 . 5, 8 . 5 and 9 . 1; the activity with pI 8 . 5 was a metallo-proteinase, and the Pi 9 . 1 activity was an elastase. The apparent molecular weight of the elastase, determined on Sephadex G-100, was 8,000 and 11,000 daltons.
mesh_terms: D000818:Animals; D002852:Chromatography, Ion Exchange; D010450:Endopeptidases / Q000097:blood*; D007525:Isoelectric Focusing; D008247:Lysosomes / Q000201:enzymology*; D008970:Molecular Weight; D009504:Neutrophils / Q000201:enzymology*; D009994:Osmolar Concentration; D010196:Pancreatic Elastase / Q000378:metabolism; D011480:Protease Inhibitors / Q000378:metabolism; D011509:Proteoglycans / Q000378:metabolism; D011817:Rabbits; D012492:Salts / Q000494:pharmacology; D013379:Substrate Specificity
chemical_list: D011480:Protease Inhibitors; D011509:Proteoglycans; D012492:Salts; D010450:Endopeptidases; D010196:Pancreatic Elastase