papain;
papayotin;
summetrin;
velardon;
papaine;
Papaya peptidase I
Class
Hydrolases;
Acting on peptide bonds (peptidases);
Cysteine endopeptidases
Reaction(IUBMB)
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'
Comment
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.
History
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
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.