title: On the substrate specificity of cathepsin L.
abstract: A view is given on the maximal hydrolysis of proteins by cathepsin L (EC 3.4.22.15) in dependence on the pH. The overall degradation of several proteins at pH values lower than pH 6.0 implies a very broad specificity, whereas at pH 7.0 and 7.5 cathepsin L seems to act on proteins cleaving only restricted specific peptide bonds. Some kinetic constants are given for the three synthetic substrates of cathepsin L which are known so far: Bz-Arg-NH2, Z-Lys-OPhNO2 and Z-Phe-Arg-NMec. They cannot be used as completely specific substrates of cathepsin L, because all of them are hydrolysed by cathepsin B and also other proteinases.
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D056668:Cathepsin L; D002403:Cathepsins / Q000378:metabolism*; D003546:Cysteine Endopeptidases; D010450:Endopeptidases; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D010455:Peptides / Q000378:metabolism; D011817:Rabbits; D051381:Rats; D013379:Substrate Specificity
chemical_list: D010455:Peptides; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D002403:Cathepsins; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; D056668:Cathepsin L; C534280:Ctsl protein, rat; D000251:Adenosine Triphosphatases; D002118:Calcium