ID 3.4.22.42 DE cathepsin O. CA The recombinant human enzyme hydrolyzes synthetic endopeptidase CA substrates including Z-Phe-Arg-NHMec and Z-Arg-Arg-NHMec. CC -!- The recombinant human enzyme is catalytically active at pH 6.0 and is CC inhibited by compound E-64. CC -!- Belongs to peptidase family C1. DR P43234, CATO_HUMAN ; Q8BM88, CATO_MOUSE ; //