EC Explorer

3.4.18.1

cathepsin X

Release of C-terminal amino acid residues with broad specificity, but lacks action on C-terminal proline. Shows weak endopeptidase activity

cathepsin B2, cysteine-type carboxypeptidase, cathepsin IV, cathepsin Z, acid carboxypeptidase, lysosomal carboxypeptidase B

37217-21-3

Cathepsin X is a lysosomal cysteine peptidase of family C1 (papain family). The pH optimum is dependent on the substrate and is 5.0 for the carboxypeptidase activity. Unstable above pH 7.0. Compound E-64, leupeptin and antipain are inhibitors, but not cystatin C. Cathepsin X is ubiquitously distributed in mammalian tissues. The propeptide is extremely short (38 amino acid residues) and the proenzyme is catalytically active. Human gene locus: 20q13.

created 1981, modified 2000