Destroys radicals which are normally produced within the cells and which are toxic to biological systems. 2 H(+) + 2 superoxide = H2O2 + O2 Binds 1 copper ion per subunit. Binds 1 zinc ion per subunit. Active between pH 5 and 10. Active between 10 and 60 degrees Celsius. Homodimer (Probable). Belongs to the Cu-Zn superoxide dismutase family.