The high activity of urease, a Ni(ii) enzyme, has several adverse effects on human health and agriculture, and its modulation needs the use of inhibitors. 1,4-Benzoquinone (BQ) irreversibly inactivates Sporosarcina pasteurii urease (SPU), with first order kinetics for both the inhibitor and the enzyme. This reaction is stoichiometrically quenched in the presence of sulphite. The 2.07 Å crystal structure of SPU bound to BQ shows the presence of a 1,4-hydroquinone moiety covalently bound to the thiol group of αCys322, a key residue found on the mobile flap regulating the substrate access to the active site. The 1.75 Å crystal structure obtained when sulphite is added to a solution of SPU previously incubated with BQ shows the presence of a 2,5-dihydroxy-benzenesulphonate moiety bound to the αCys322 thiol group. These data reveal how the active site cysteine reacts with a prototypical BQ moiety, found in a large number of natural substances potentially suitable to control the urease activity.

Inactivation of urease by 1,4-benzoquinone: Chemistry at the protein surface

MAZZEI, LUCA;MUSIANI, FRANCESCO;CIURLI, STEFANO LUCIANO
2016

Abstract

The high activity of urease, a Ni(ii) enzyme, has several adverse effects on human health and agriculture, and its modulation needs the use of inhibitors. 1,4-Benzoquinone (BQ) irreversibly inactivates Sporosarcina pasteurii urease (SPU), with first order kinetics for both the inhibitor and the enzyme. This reaction is stoichiometrically quenched in the presence of sulphite. The 2.07 Å crystal structure of SPU bound to BQ shows the presence of a 1,4-hydroquinone moiety covalently bound to the thiol group of αCys322, a key residue found on the mobile flap regulating the substrate access to the active site. The 1.75 Å crystal structure obtained when sulphite is added to a solution of SPU previously incubated with BQ shows the presence of a 2,5-dihydroxy-benzenesulphonate moiety bound to the αCys322 thiol group. These data reveal how the active site cysteine reacts with a prototypical BQ moiety, found in a large number of natural substances potentially suitable to control the urease activity.
Mazzei, Luca; Cianci, M.; Musiani, Francesco; Ciurli, STEFANO LUCIANO
File in questo prodotto:
File Dimensione Formato  
c6dt00652c.pdf

accesso aperto

Tipo: Versione (PDF) editoriale
Licenza: Licenza per Accesso Aperto. Creative Commons Attribuzione (CCBY)
Dimensione 1.21 MB
Formato Adobe PDF
1.21 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11585/585357
Citazioni
  • ???jsp.display-item.citation.pmc??? 14
  • Scopus 48
  • ???jsp.display-item.citation.isi??? 47
social impact