Cysteine Proteinases

Papain-like

Hydrogen Bonding Diagram

Blue arrows indicate hydrogen bonding interactions between the enzyme and the inhibitors

General information about papain-like cysteine proteinases

Structural Comparisons

Overlap of fitted inhibitor structures

Overlap of fitted protein structures.

The representatives are 2act (Actinidin), 1huc (Cathepsin B), 1ppo (Papaya Protease Omega) & 1ppn (Papain)

PDB Code	PDB Info	Protein	Source	E.C. no.	Res./Å	R-factor	Inhibitor	Covalent	Inhibitor bound in active site
1AEC	View	Actinidin	Actinidia chinensis	3.4.22.14	1.9	14.5	E-64 (Aspergillus japonicus)	Yes	View
1HUC	View	Cathepsin B	Homo sapiens	3.4.22.1	2.1	16.4	Oxidised Cys-25	-	-
1PPO	View	Papaya Protease Omega	Carica papaya	3.4.22.30	1.8	15.5	Mercury derivative of Cys-25	Ionic	-
1PAD	View	Papain	Carica papaya	3.4.22.2	2.8	-	Ace-Ala-Ala-Phe-Methylenylalanyl	Yes	View
1PE6	View	Papain	Carica papaya	3.4.22.2	2.1	15.9	E-64-C	Yes	View
1PIP	View	Papain	Carica papaya	3.4.22.2	1.7	19.6	Succinyl-Gln-Val-Val-Ala-Ala-P-Nitroanilide	No	View
1POP	View	Papain	Carica papaya	3.4.22.2	2.1	-	Leupeptin (N-Ace-L-Leu-L-Leu-L-Argininal)	Yes	View
1PPD	View	Papain	Carica papaya	3.4.22.2	2.0	14.5	2-Mercaptoethanol	Yes	View
1PPN	View	Papain	Carica papaya	3.4.22.2	1.6	16.0	Oxidised Cys-25	-	-
1PPP	View	Papain	Carica papaya	3.4.22.2	1.9	19.4	E-64-C	Yes	View
1STF	View	Papain (Cys 25 Carboxymethylated)	Carica papaya	3.4.22.2	2.4	19.0	Stefin B Mutant (C8S) (Homo sapiens)	No	View
2ACT	View	Actinidin	Actinidia chinensis	3.4.22.14	1.7	17.1	Oxidised Cys-25	-	-
2PAD	View	Papain	Carica papaya	3.4.22.2	2.8	-	Cysteinyl derivative of Cys-25	Yes	View
4PAD	View	Papain	Carica papaya	3.4.22.2	2.8	-	Tosyl-Methylenyllysyl	Yes	View
5PAD	View	Papain	Carica papaya	3.4.22.2	2.8	-	Boc-Gly-Phe-Methylenylglycyl	Yes	View
6PAD	View	Papain	Carica papaya	3.4.22.2	2.8	-	Boc-Phe-Methylenylalanyl	Yes	View
9PAP	View	Papain	Carica papaya	3.4.22.2	1.7	16.1	Oxidised Cys-25	-	-