Investigation of the active site of human placenta glutathione transferase π by means of a spin-labelled glutathione analogue

A. M. Caccuri, F. Polizio, F. Piemonte, P. Tagliatesta, G. Federici, A. Desideri

Research output: Contribution to journalArticlepeer-review

Abstract

A spin-labelled analogue (sl-glutathione) has been used in order to characterize the active site of human placenta glutathione transferase π. The sl-glutathione shows a competitive inhibition towards glutathione (Ki = 14 μM). Binding of sl-glutathione to the enzyme, followed by electron paramagnetic resonance spectroscopy, gives a Kd of 3 μM and two identical binding sites for dimeric unit. Inhibition of the enzyme, by modification of the Cys-47 residue, completely prevents the binding of sl-glutathione. The same results are obtained by monitoring the binding of glutathione by means of fluorescence spectroscopy. It is concluded that integrity of the thiolate of Cys-47 is necessary to maintain an active conformation of the enzyme able to efficiently bind glutathione into the active site.

Original languageEnglish
Pages (from-to)265-268
Number of pages4
JournalBiochimica et Biophysica Acta (BBA)/Protein Structure and Molecular
Volume1122
Issue number3
DOIs
Publication statusPublished - Aug 21 1992

Keywords

  • EPR
  • G-site
  • Glutathione
  • GSH transferase π
  • Spin-labelled glutathione

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology
  • Structural Biology

Fingerprint Dive into the research topics of 'Investigation of the active site of human placenta glutathione transferase π by means of a spin-labelled glutathione analogue'. Together they form a unique fingerprint.

Cite this