Gold-based drugs typically behave as strong inhibitors of the enzyme thioredoxin reductase (hTrxR), possibly as the consequence of direct Gold(I) coordination to its active site selenocysteine. To gain a deeper insight into the molecular basis of enzyme inhibition and prove gold-selenocysteine coordination, the reactions of three parent Gold(I) NHC compounds with the synthetic C-terminal dodecapeptide of hTrxR containing Selenocysteine at position 498, were investigated by electrospray ionization mass spectrometry (ESI-MS). Formation of 1:1 Gold-peptide adducts, though in highly different amounts, was demonstrated in all cases. In these adducts the same [Au-NHC] + moiety is always associated to the intact peptide. Afterward, tandem MS experiments, conducted on a specific Gold-peptide complex, pointed out that Gold is coordinated to the selenolate group. The relatively large strength of the Gold-selenolate coordinative bond well accounts for potent enzyme inhibition typically afforded by these Gold(I) compounds. In a selected case, the time course of enzyme inhibition was explored. Interestingly, enzyme inhibition turned out to show up very quickly and reached its maximum just few minutes after mixing. Overall, the present results offer some clear insight into the process of thioredoxin reductase inhibition by Gold-based compounds.

Insights on the mechanism of thioredoxin reductase inhibition by Gold N-heterocyclic carbene compounds using the synthetic linear Selenocysteine containing C-terminal peptide hTrxR(488-499): An ESI-MS investigation

Pratesi, A.
Primo
;
GABBIANI, CHIARA
Secondo
;
2014-01-01

Abstract

Gold-based drugs typically behave as strong inhibitors of the enzyme thioredoxin reductase (hTrxR), possibly as the consequence of direct Gold(I) coordination to its active site selenocysteine. To gain a deeper insight into the molecular basis of enzyme inhibition and prove gold-selenocysteine coordination, the reactions of three parent Gold(I) NHC compounds with the synthetic C-terminal dodecapeptide of hTrxR containing Selenocysteine at position 498, were investigated by electrospray ionization mass spectrometry (ESI-MS). Formation of 1:1 Gold-peptide adducts, though in highly different amounts, was demonstrated in all cases. In these adducts the same [Au-NHC] + moiety is always associated to the intact peptide. Afterward, tandem MS experiments, conducted on a specific Gold-peptide complex, pointed out that Gold is coordinated to the selenolate group. The relatively large strength of the Gold-selenolate coordinative bond well accounts for potent enzyme inhibition typically afforded by these Gold(I) compounds. In a selected case, the time course of enzyme inhibition was explored. Interestingly, enzyme inhibition turned out to show up very quickly and reached its maximum just few minutes after mixing. Overall, the present results offer some clear insight into the process of thioredoxin reductase inhibition by Gold-based compounds.
2014
Pratesi, A.; Gabbiani, Chiara; Michelucci, E.; Ginanneschi, M.; Papini, A. M.; Rubbiani, R.; Ott, I.; Messori, L.
File in questo prodotto:
File Dimensione Formato  
JIB pratesi 300913.pdf

accesso aperto

Descrizione: Articolo principale
Tipologia: Documento in Post-print
Licenza: Creative commons
Dimensione 1.41 MB
Formato Adobe PDF
1.41 MB Adobe PDF Visualizza/Apri
JInorgBiochem_2014_136_161-169.pdf

solo utenti autorizzati

Descrizione: Articolo principale
Tipologia: Versione finale editoriale
Licenza: NON PUBBLICO - Accesso privato/ristretto
Dimensione 884.48 kB
Formato Adobe PDF
884.48 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

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: https://hdl.handle.net/11568/464267
Citazioni
  • ???jsp.display-item.citation.pmc??? 21
  • Scopus 84
  • ???jsp.display-item.citation.isi??? 79
social impact