IUBMB Enzyme Nomenclature


Accepted name: cathepsin O

Reaction: The recombinant human enzyme hydrolyses synthetic endopeptidase substrates including Z-Phe-Arg-NHMec and Z-Arg-Arg-NHMec

Comments: Cathepsin O is a lysosomal cysteine peptidase of family C1 (papain family). The recombinant human enzyme is catalytically active at pH 6.0 and is inhibited by compound E-64. Cathepsin O is ubiquitously expressed in human tissues and the human gene locus is 4q31-32

Links to other databases: BRENDA, EXPASY, KEGG, MEROPS, Metacyc, CAS registry number: 162032-86-2


1. Santamaría, I., Pendás, A.M., and López-Otín, C. Genomic structure and chromosomal localization of a human cathepsin O gene (CTSO). Genomics 53 (1998) 231-234. [PMID: 9790772]

2. Velasco, G., Ferrando, A.A., Puente, X.S., Sanchez, L.M. and López-Otín, C. Human cathepsin O. Molecular cloning from a breast carcinoma, production of the active enzyme in Escherichia coli, and expression analysis in human tissues. J. Biol. Chem. 269 (1994) 27136-27142. [PMID: 7929457]

[EC created 2000]

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