Purification and ultrastructural localization of a copper–zinc superoxide dismutase (CuZnSOD) from the entomopathogenic and acaricide fungus Metarhizium anisopliae

Abstract

The entomopathogenic fungus Metarhizium anisopliae contains three superoxide dismutases. One of these enzymes was purified and partially characterized as a CuZnSOD. The enzyme has an estimated molecular mass of 30 690 Da and a specific activity of 3838.89 U mg−1. SDS-PAGE and 2D gels show a single band of protein in the fractions eluted from the gel filtration column with a molecular mass of 20 000 and ∼15 000 Da, respectively, and a pI of 6.0. These results suggest that the native enzyme is a dimer consisting of two subunits. Polyclonal antiserum were raised against purified CuZnSOD and used to determine its subcellular localization by immunoelectron microscopy. M. anisopliae CuZnSOD is present in the cell wall.