Literature summary for 3.4.22.2 extracted from

Redzynia, I.; Ljunggren, A.; Bujacz, A.; Abrahamson, M.; Jaskolski, M.; Bujacz, G.
Crystal structure of the parasite inhibitor chagasin in complex with papain allows identification of structural requirements for broad reactivity and specificity determinants for target proteases (2009), FEBS J., 276, 793-806.

Crystallization (Commentary)

Crystallization (Comment)	Organism
a complex of chagasin, a protein inhibitor from Trypanosoma cruzi, and papain is crystallized by using the hanging-drop vapor diffusion method at 18°C, the high-resolution crystal structure shows an inhibitory wedge comprising three loops, which forms a number of contacts responsible for the high-affinity binding, the present chagasin-papain complex provides a reliable model of chagasin-cruzipain interactions	Carica papaya

Crystallization (Comment)

Organism

a complex of chagasin, a protein inhibitor from Trypanosoma cruzi, and papain is crystallized by using the hanging-drop vapor diffusion method at 18°C, the high-resolution crystal structure shows an inhibitory wedge comprising three loops, which forms a number of contacts responsible for the high-affinity binding, the present chagasin-papain complex provides a reliable model of chagasin-cruzipain interactions

Carica papaya

Inhibitors

Inhibitors	Comment	Organism	Structure
chagasin	protease inhibitor, inhibits all C1 family proteases	Carica papaya
cystatin B	-	Carica papaya

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
0.06	-	carboxybenzoyl-Phe-Arg-7-(4-methyl)coumarylamide	100 mM sodium phosphate buffer, pH 6.0, containing 1 mM dithiothreitol and 1 mM EDTA	Carica papaya

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
additional information	Carica papaya	papain is the founding member of the large C1 family of papain-like cysteine proteases	?	-	?

Organism

Organism	UniProt	Comment	Textmining
Carica papaya	P00784	-	-

Purification (Commentary)

Purification (Comment)	Organism
active papain is prepared from the commercial papaya latex enzyme through affinity purification on Sepharose 4B	Carica papaya

Source Tissue

Source Tissue	Comment	Organism	Textmining
commercial preparation	papaya latex enzyme	Carica papaya	-
latex	-	Carica papaya	-

Storage Stability

Storage Stability	Organism
-80°C, purified enzyme can be activated to at least 65% of its original activity after storage at -80°C for up to 3 months	Carica papaya

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
carboxybenzoyl-Phe-Arg-7-(4-methyl)coumarylamide + H2O	fluorogenic substrate	Carica papaya	carboxybenzoyl-Phe-Arg + 7-amino-4-methylcoumarin	-	?
additional information	papain is the founding member of the large C1 family of papain-like cysteine proteases	Carica papaya	?	-	?

Synonyms

Synonyms	Comment	Organism
papain	-	Carica papaya

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
6	-	assay at	Carica papaya

Ki Value [mM]

Ki Value [mM]	Ki Value maximum [mM]	Inhibitor	Comment	Organism	Structure
0.000000036	-	chagasin	inactivation of papain is very fast, rate constant for inactivation is 1500 mM/s	Carica papaya