The specificity of bovine spleen cathepsin S. A comparison with rat liver cathepsins L and B

Biochem J. 1989 Dec 1;264(2):475-81. doi: 10.1042/bj2640475.


The peptide-bond-specificity of bovine spleen cathepsin S in the cleavage of the oxidized insulin B-chain and peptide methylcoumarylamide substrates was investigated and the results are compared with those obtained with rat liver cathepsins L and B. Major cleavage sites in the oxidized insulin B-chain generated by cathepsin S are the bonds Glu13-Ala14, Leu17-Val18 and Phe23-Tyr26; minor cleavage sites are the bonds Asn3-Gln4, Ser9-His10 and Leu15-Tyr16. The bond-specificity of this proteinase is in part similar to the specificities of cathepsin L and cathepsin N. Larger differences are discernible in the reaction with synthetic peptide substrates. Cathepsin S prefers smaller neutral amino acid residues in the subsites S2 and S3, whereas cathepsin L efficiently hydrolyses substrates with bulky hydrophobic residues in the P2 and P3 positions. The results obtained from inhibitor studies differ somewhat from those based on substrates. Z-Phe-Ala-CH2F (where Z- represents benzyloxycarbonyl-) is a very potent time-dependent inhibitor for cathepsin S, and inhibits this proteinase 30 times more efficiently than it does cathepsin L and about 300 times better than it does cathepsin B. By contrast, the peptidylmethanes Z-Val-Phe-CH3 and Z-Phe-Lys(Z)-CH3 inhibit competitively both cathepsin S and cathepsin L in the micromolar range.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cathepsin B / metabolism*
  • Cathepsin L
  • Cathepsins / metabolism*
  • Cattle
  • Cysteine Endopeptidases
  • Endopeptidases*
  • Kinetics
  • Liver / enzymology*
  • Molecular Sequence Data
  • Rats
  • Spleen / enzymology*
  • Substrate Specificity


  • Cathepsins
  • Endopeptidases
  • Cysteine Endopeptidases
  • Cathepsin B
  • Cathepsin L
  • Ctsl protein, rat
  • cathepsin S