A Single Mutation is Sufficient to Modify the Metal Selectivity and Specificity of a Eukaryotic Manganese Superoxide Dismutase to Encompass Iron

Chemistry. 2018 Apr 6;24(20):5303-5308. doi: 10.1002/chem.201704655. Epub 2017 Dec 12.

Abstract

We have generated a site-directed mutant of the manganese superoxide dismutase SOD-3 of C.elegans (MnSOD-3) which modifies the metal specificity of the enzyme. While wild-type MnSOD-3 functions with manganese in the active site (3600 U mg-1 of protein) it has little or no activity when iron is incorporated. However, when histidine replaces glutamine 142 in the active site, the enzyme retains 50 % of its activity and becomes cambialistic for its metal cofactor exhibiting very similar specific activity with either manganese or iron.

Keywords: enzymes; iron; manganese; metalloprotein; superoxide dismutase.

MeSH terms

  • Catalytic Domain
  • DNA
  • Eukaryota
  • Gene Expression
  • Glutamine / chemistry
  • Histidine / chemistry
  • Iron / chemistry*
  • Metals / chemistry*
  • Molecular Dynamics Simulation
  • Mutation
  • Oxidation-Reduction
  • Protein Binding
  • Protein Conformation
  • Sensitivity and Specificity
  • Static Electricity
  • Superoxide Dismutase / chemistry*
  • Superoxide Dismutase / genetics

Substances

  • Metals
  • Glutamine
  • Histidine
  • DNA
  • Iron
  • Superoxide Dismutase