Reaction: Hydrolysis of proteins with broad specificity for peptide bonds, but preference for an amino acid bearing a large hydrophobic side chain at the P2 position. Does not accept Val in P1'
Other name(s): papayotin; summetrin; velardon; papaine; Papaya peptidase I
Comments: Type example of peptidase family C1 from latex of the papaya (Carica papaya) fruit. Inhibited by compound E-64 and proteins of the cystatin family. Formerly EC 18.104.22.168
Links to other databases: BRENDA, EXPASY, GTD, KEGG, MEROPS, Metacyc, PDB, CAS registry number: 9001-73-4
1. Kamphuis, I.G., Drenth, J. and Baker, E.N. Thiol proteases. Comparative studies based on the high-resolution structures of papain and actinidin, and on amino acid sequence information for cathepsins B and H, and stem bromelain. J. Mol. Biol. 182 (1985) 317-329. [PMID: 3889350]
2. Ménard, R. and Storer, A.C. Papain. In: Handbook of Proteolytic Enzymes, Barrett, A.J., Rawlings, N.D. and Woessner, J.F. eds), p.555-557 (1998) Academic Press, London.