NMR evidence for perturbation of the copper coordination sphere upon chemical modification of arginine 141 in bovine Cu,Zn superoxide dismutase

https://doi.org/10.1016/0003-9861(91)90032-EGet rights and content

Abstract

The reaction of the Cu,Co derivative of bovine Cu,Zn superoxide dismutase with phenylglyoxal or butanedione, which are known to inactivate the enzyme by selectively binding to Arg 141, has been studied by 1H NMR. Several 1H NMR lines of the copper-liganding histidine residues were perturbed, reproducing an effect so far observed only in the case of binding of anions to this protein. The room temperature EPR spectrum of the modified Cu,Zn protein was altered very slightly, indicating that the geometry of the copper site was not grossly affected by the modification. NMR and EPR changes were reversed by dialysis in the case of the reversible butanedione adduct. These data show that the coordination of the copper in Cu,Zn superoxide dismutase can be destabilized by modifications occurring at a neighboring but not a metal-liganding residue. It is suggested that part of the NMR effects seen on copper ligands in the case of anion binding are produced by interaction of anions with Arg 141, rather than by direct ligand replacement.

References (18)

  • M. Paci et al.

    J. Biol. Chem

    (1988)
  • L. Banci et al.

    J. Biol. Chem

    (1989)
  • O. Bermingham-McDonogh et al.

    Biochem. Biophys. Res. Commun

    (1982)
  • J. Hochmann et al.

    J. Magn. Res

    (1980)
  • M. Paci et al.

    FEBS Lett

    (1990)
  • D. Cocco et al.

    Biochim. Biophys. Acta

    (1983)
  • R.A. Lieberman et al.

    J. Biol. Chem

    (1982)
  • H.L. Van Camp et al.

    Biochim. Biophys. Acta

    (1982)
  • J.A. Fee et al.

    J. Biol. Chem

    (1972)
There are more references available in the full text version of this article.

Cited by (0)

Supported in part by the C.N.R. special project “Chimica Fine II.”

View full text