Abstract: The catalytic hydrolysis of a methionyl-peptide substrate by a methionine aminopeptidase active site model cluster was investigated at the DF/B3LYP level of theory, in the gas-phase and in the protein environment. Zn(II), Co(II), Mn(II), and Fe(II) transition metals were examined as the potential catalytic metals of this enzyme involved in protein maturation. Two different mechanisms in which Glu204 was present as protonated or deprotonated residue were considered. The energetic profiles show lower barriers as the protonated glutamate is involved. The rate-determining step of the hydrolysis reaction is always the nucleophilic addition of the hydroxide on substrate carbon, followed by less energetically demanding methionine-peptide C-N bond scission. The lowest activation energy is obtained in the case of zinc dication while the other metals show very high energetic barriers, so that methionine aminopeptidase can be in principle recognized as a dizinc enzyme.

Which one among Zn(II), Co(II), Mn(II) and Fe(II) is the most efficient ion for the Methionine Aminopeptidase catalyzed reaction

RUSSO N;TOSCANO, Marirosa
2007-01-01

Abstract

Abstract: The catalytic hydrolysis of a methionyl-peptide substrate by a methionine aminopeptidase active site model cluster was investigated at the DF/B3LYP level of theory, in the gas-phase and in the protein environment. Zn(II), Co(II), Mn(II), and Fe(II) transition metals were examined as the potential catalytic metals of this enzyme involved in protein maturation. Two different mechanisms in which Glu204 was present as protonated or deprotonated residue were considered. The energetic profiles show lower barriers as the protonated glutamate is involved. The rate-determining step of the hydrolysis reaction is always the nucleophilic addition of the hydroxide on substrate carbon, followed by less energetically demanding methionine-peptide C-N bond scission. The lowest activation energy is obtained in the case of zinc dication while the other metals show very high energetic barriers, so that methionine aminopeptidase can be in principle recognized as a dizinc enzyme.
2007
enzymes
File in questo prodotto:
Non ci sono file associati a questo prodotto.

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/20.500.11770/141985
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 55
  • ???jsp.display-item.citation.isi??? 56
social impact