Reconstitution of Cu,Zn-superoxide dismutase by the Cu(I).glutathione complex.

Abstract

The reconstitution of Cu,Zn-superoxide dismutase from the copper-free protein by the Cu(I).GSH complex was monitored by: (a) EPR and optical spectroscopy upon reoxidation of the enzyme-bound copper; (b) NMR spectroscopy following the broadening of the resonances of the Cu(I).GSH complex after addition of Cu-free,Zn-superoxide dismutase; and (c) NMR spectroscopy of the Cu-free,Co(II) enzyme following the appearance of the isotropically shifted resonances of the Cu(I), Co enzyme, Cu(I).GSH was found to be a very stable complex in the presence of oxygen and a more efficient copper donor to the copper-free enzyme than other low molecular weight Cu(II) complexes. In particular, 100% reconstitution was obtained with stoichiometric copper at any GSH:copper ratio between 2 and 500. Evidence was obtained for the occurrence of a Cu(I).GSH.protein intermediate in the reconstitution process. In view of the inability of copper-thionein to reconstitute Cu,Zn-superoxide dismutase and of the detection of copper.GSH complexes in copper-over-loaded hepatoma cells (Freedman, J.H., Ciriolo, M.R., and Peisach, J. (1989) J. Biol. Chem. 264, 5598-5605), Cu(I).GSH is proposed as a likely candidate for copper donation to Cu-free,Zn-superoxide dismutase in vivo.

• Authors: M R Ciriolo, A Desideri, M Paci, G Rotilio
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 265 Issue 19 Pg. 11030-4 (Jul 05 1990) ISSN: 0021-9258 [Print] United States
• PMID: 2162829 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Copper
• Superoxide Dismutase
• Glutathione

Topics

• Animals
• Binding Sites
• Cattle
• Copper (metabolism)
• Electron Spin Resonance Spectroscopy
• Erythrocytes (enzymology)
• Glutathione (metabolism)
• Magnetic Resonance Spectroscopy
• Superoxide Dismutase (metabolism)