COMPARATIVE STABILITY STUDIES ON THE IRON AND MANGANESE FORMS OF THE CAMBIALISTIC SUPEROXIDE-DISMUTASE FROM PROPIONIBACTERIUM-SHERMANII

The superoxide dismutase of Propionibacterium shermanii shows similar activity with iron and manganese bound at the active site of the prote in. On the other hand, the iron form, in comparison to the manganese f orm, exhibits higher stability towards thermal- and pH-dependent inact ivation, Upon inactivation the metal ions are released from the active site, Thus, in comparison to the manganese form, a higher stability o f the iron-protein complex might be the triggering reason for this beh avior. (C) 1997 Federation of European Biochemical Societies.