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

AUTOR(ES)

Mateo, Héctor, Marín, Clotilde, Pérez-Cordón, Gregorio, Sánchez-Moreno, Manuel

FONTE

Memórias do Instituto Oswaldo Cruz

DATA DE PUBLICAÇÃO

2008-05

RESUMO

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 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 low-mass organelles (SOD II and SOD I) and the mitochondrion (SOD III), where these enzymes play an important role in minimizing oxidative damage.

Documentos Relacionados

• Induction of superoxide dismutases in Escherichia coli by manganese and iron.
• Purification and characterization of an 80-kilodalton Trypanosoma cruzi urinary antigen.
• Isolation and reconstitution of iron- and manganese-containing superoxide dismutases from Bacteroides thetaiotaomicron.
• The Cu,Zn superoxide dismutases of Aspergillus flavus, Aspergillus niger, Aspergillus nidulans, and Aspergillus terreus: purification and biochemical comparison with the Aspergillus fumigatus Cu,Zn superoxide dismutase.
• Molecular and biochemical characterisation of Trypanosoma cruzi phosphofructokinase