Exit of products from the active site of human glutathione transferase P1-1 is promoted by valine 10

Chiara Micaloni, Anna P. Mazzetti, Marzia Nuccetelli, Jamie Rossjohn, William J. McKinstry, Giovanni Antonini, Anna M. Caccuri, Aaron J. Oakley, Giorgio Federici, Giorgio Ricci, Michael W. Parker, Mario Lo Bello

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3 Citations (Scopus)

Abstract

In search of potential residues involved in co-substrate recognition or product dissociation we have probed the electrophilic binding site (H-site) of human placental glutathione transferase (GST P1-1) by mutating two valines (Val 10 and Val 35) into glycine and alanine, respectively. The results demonstrate that Val35Ala behaves similar to wild type, whereas Val10Gly exhibits a strong decrease of kcat towards two selected co-substrates, ethacrynic acid and 1-chloro-2,4-dinitrobenzene. Kinetic, spectroscopic and crystallographic analysis of the Val10Gly mutant enzyme indicate that Val 10, located on the floor of the H-site, may orient products and help them to leave the active site.

Original languageEnglish
Pages (from-to)192-195
Number of pages4
JournalChemico-Biological Interactions
Volume133
Issue number1-3
Publication statusPublished - 28 Feb 2001
Externally publishedYes

Keywords

  • Catalytic mechanism
  • Glutathione transferase
  • H-site
  • Site-directed mutagenesis

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