IUBMB Enzyme Nomenclature


Accepted name: glycyl endopeptidase

Reaction: Preferential cleavage: Gly, in proteins and small molecule substrates

Other names: papaya peptidase B; papaya proteinase IV; glycine-specific proteinase; chymopapain; Papaya proteinase 4; PPIV; chymopapain M

Comments: From the papaya plant, Carica papaya. Not inhibited by chicken cystatin, unlike most other homologues of papain, but In peptidase family C1 (papain family)

Links to other databases: BRENDA, EXPASY, KEGG, MEROPS, Metacyc, PDB, CAS registry number: 149719-24-4


1. Polgár, L. Isolation of highly active papaya peptidases A and B from commercial chymopapain. Biochim. Biophys. Acta 658 (1981) 262-269. [PMID: 7018581]

2. Buttle, D.J., Kembhavi, A.A., Sharp, S.L., Shute, R.E., Rich, D.H. and Barrett, A.J. Affinity purification of the novel cysteine proteinase papaya proteinase IV and papain from papaya latex. Biochem. J. 261 (1989) 469-476. [PMID: 2505761]

3. Ritonja, A., Buttle, D.J., Rawlings, N.D., Turk, V. and Barrett, A.J. Papaya proteinase IV amino acid sequence. FEBS Lett. 258 (1989) 109-112. [PMID: 2591528]

4. Buttle, D.J., Ritonja, A., Pearl, L.H., Turk, V. and Barrett, A.J. Selective cleavage of glycyl bonds by papaya proteinase IV. FEBS Lett. 260 (1990) 195-197. [PMID: 2404797]

5. Buttle, D.J., Ritonja, A., Dando, P.M., Abrahamson, M., Shaw, E.N., Wikstrom, P., Turk, V. and Barrett, A.J. Interaction of papaya proteinase IV with inhibitors. FEBS Lett. 262 (1990) 58-60. [PMID: 1690669]

[EC created 1992]

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