Cys25-nitrosylation inactivates papain.
Nitric oxide (NO) may modulate the catalytic activity of cysteine proteases. In the present study, the inhibitory effect of NO, released by the NO-donors (+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide and nitroprusside, on papain action is reported. Papain inactivation via NO-mediated nitrosylation of the Cys25 catalytic residue represents a molecular model for cysteine protease inhibition.
Venturini
G
G
Department of Biology, University of Rome Tre, Italy.
Fioravanti
E
E
Colasanti
M
M
Persichini
T
T
Ascenzi
P
P
D003545:Cysteine / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism / Q000494:pharmacology*; D009574:Nitro Compounds / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D010206:Papain / Q000037:antagonists & inhibitors* / Q000378:metabolism*
D015853:Cysteine Proteinase Inhibitors; D009574:Nitro Compounds; D009599:Nitroprusside; D009569:Nitric Oxide; C061872:FK 409; D010206:Papain; D003545:Cysteine