Cathepsin S. The cysteine proteinase from bovine lymphoid tissue is distinct from cathepsin L (EC 3.4.22.15).
Cathepsin S was purified from bovine spleen by acid autolysis, (NH4)2SO4 fractionation and chromatography on CM-Sephadex C-50, CM-cellulose and activated-thiol-Sepharose. Cathepsin L was isolated from lysosomal fractions of rat liver, rat kidney and bovine liver. Generally, cathepsin L was bound tightly to CM-Sephadex C-50. Preparations of cathepsin L from rat liver, rat kidney and bovine liver were shown to have kinetic constants for the substrate benzyloxycarbonyl-Phe-Arg-7-(4-methyl)coumarylamide in the same range (Km 2-3 microM). Benzyloxycarbonyl-Phe-Phe-diazomethane proved to be a sensitive irreversible inhibitor of cathepsin L from different species. Cathepsin S differed in all these characteristics from cathepsin L. A polyclonal antibody to cathepsin L from rat reacted with bovine cathepsin L but not with bovine cathepsin S.
D000818:Animals; D000906:Antibodies / Q000032:analysis; D056668:Cathepsin L; D002403:Cathepsins / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism*; D002417:Cattle; D002850:Chromatography, Gel; D003546:Cysteine Endopeptidases; D003978:Diazomethane / Q000031:analogs & derivatives / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D008970:Molecular Weight; D051381:Rats; D013154:Spleen / Q000201:enzymology*; D013379:Substrate Specificity
D000906:Antibodies; D003978:Diazomethane; C031947:benzyloxycarbonylphenylalanylphenylalanine diazomethyl ketone; D002403:Cathepsins; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; D056668:Cathepsin L; C534280:Ctsl protein, rat; C028217:cathepsin S