EC	3.4.22.2
Accepted name:	papain
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.
References:	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: Barrett, A.J., Rawlings, N.D. and Woessner, J.F. (Ed.), Handbook of Proteolytic Enzymes, Academic Press, London, 1998, pp. 555–557.
[EC 3.4.22.2 created 1961 as EC 3.4.4.10, transferred 1972 to EC 3.4.22.2, modified 1976, modified 2000]