Proteoglycan-degrading enzymes of rabbit fibroblasts and granulocytes.
A neutral proteinase secreted by rabbit synovial fibroblasts in parallel with specific collagenase was partially purified by ion-exchange chromatography. At pH 7.6 this proteinase degraded 35S-labelled bovine nasal proteoglycan and azo-casein. The enzymic activity was inhibited by EDTA, 1,10-phenanthroline and serum, whereas di-isopropyl phosphorofluoridate and soya-bean trypsin inhibitor had little effect. By gel filtration the apparent mol.wt. of the enzyme was 25000. The fibroblast neutral proteinase was compared with the proteoglycan-degrading neutral proteinases of rabbit polymorphonuclear-leucocyte granules. Two distinct activities were found in the granules: one was inhibited by soya-bean trypsin inhibitor and the other by EDTA. The proteoglycan-degrading proteinases of rabbit fibroblasts and polymorphonuclear leucocytes at acid pH also were examined. Both cathepsin D and a thiol-dependent proteinase contributed to the degradation of proteoglycan at pH 4.5.
D000818:Animals; D002850:Chromatography, Gel; D005347:Fibroblasts / Q000201:enzymology*; D006098:Granulocytes / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D009504:Neutrophils / Q000201:enzymology; D010447:Peptide Hydrolases / Q000097:blood / Q000378:metabolism*; D011480:Protease Inhibitors; D011509:Proteoglycans; D011817:Rabbits; D014783:Viscosity
D011480:Protease Inhibitors; D011509:Proteoglycans; D010447:Peptide Hydrolases