Purification and biochemical characterization of four iron superoxide dismutases in Trypanosoma cruzi

Héctor Mateo, Clotilde Marín, Gregorio Pérez-Cordón, Manuel Sánchez-Moreno
2008 Memórias do Instituto Oswaldo Cruz  
Four superoxide dismutase (SOD) activities (SOD I, II, III, and IV) have been characterized in the epimastigote form of Trypanosoma cruzi. The total extract was subjected to two successive ammonium sulphate additions between 35 and 85%, and the resulting fraction was purified using two continuous chromatography processes (ion exchange and filtration). Enzymes were insensitive to cyanide but sensitive to hydrogen peroxide, properties characteristic of iron-containing SODs. The molecular masses
more » ... molecular masses of the different SODs were 20 kDa (SOD I), 60 kDa (SOD II), 50 kDa (SOD III) and 25 kDa (SOD IV), whereas the isoelectric points were 6.9, 6.8, 5.2 and 3.8, respectively. Subcellular location and digitonin experiments have shown that these SODs are mainly cytosolic, with small amounts in the lowmass organelles (SOD II and SOD I) and the mitochondrion (SOD III), where these enzymes play an important role in minimizing oxidative damage.
doi:10.1590/s0074-02762008000300008 pmid:18592100 fatcat:g5itwnlszfd5hequy46womkamm