Studies on the cathepsins in elastic cartilage.
1. The presence of several enzymes in rabbit ear cartilage was examined by a quantitative method that permits the incubation of a fixed weight of cartilage sections (18mum.) with an appropriate exogeneous substrate. 2. As the presence of cathepsins B and D in cartilage has already been established, evidence is now provided to show that cathepsins A and C are also present and are maximally active at pH5. 3. Cathepsin A was recognized by its hydrolysis of benzyloxycarbonyl-glutamyl-tyrosine and cathepsin C by its hydrolysis of glycyl-tyrosine amide; the cartilage also hydrolysed benzyloxycarbonyl-glutamyl-phenylalanine and benzoyl-dl-phenylalanine 2-naphthyl ester at pH5. 4. The acid phosphatase activity and the DNA content of cartilage have also been measured to provide a basis for comparison with the cathepsin activity of cartilage obtained from other sites and species.
D000135:Acid Phosphatase / Q000378:metabolism; D000577:Amides; D000818:Animals; D001329:Autolysis; D002356:Cartilage / Q000201:enzymology*; D002403:Cathepsins / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D004151:Dipeptides; D004423:Ear; D004547:Elastic Tissue / Q000201:enzymology*; D006454:Hemoglobins; D006863:Hydrogen-Ion Concentration; D008722:Methods; D011817:Rabbits; D014574:Uronic Acids / Q000378:metabolism
D000577:Amides; D004151:Dipeptides; D006454:Hemoglobins; D014574:Uronic Acids; D004247:DNA; D000135:Acid Phosphatase; D002403:Cathepsins