Back to Search
Start Over
Functional expression and characterization of an iron-containing superoxide dismutase of Acanthamoeba castellanii.
- Source :
-
Parasitology research [Parasitol Res] 2012 Oct; Vol. 111 (4), pp. 1673-82. Date of Electronic Publication: 2012 Jul 03. - Publication Year :
- 2012
-
Abstract
- Acanthamoeba spp. are free-living amoebae, but opportunistic infections of some strains of the organisms cause severe diseases such as acanthamoebic keratitis, pneumonitis, and granulomatous amoebic encephalitis in human. In this study, we identified a gene encoding iron superoxide dismutase of Acanthamoeba castellanii (AcFe-SOD) and characterized biochemical and functional properties of the recombinant enzyme. Multiple sequence alignment of the deduced amino acid sequence of AcFe-SOD with those of previously reported iron-containing SODs (Fe-SODs) from other protozoan parasites showed that AcFe-SOD shared common metal-binding residues and motifs that are conserved in Fe-SODs. The genomic length of the AcFe-SOD gene was 926 bp consisting of five exons interrupted by four introns. The recombinant AcFe-SOD showed similar biochemical characteristics with its native enzyme and shared typical biochemical properties with other characterized Fe-SODs, including molecular structure, broad pH optimum, and sensitivity to hydrogen peroxide. Immunolocalization analysis revealed that the enzyme localized in the cytosol of the trophozoites. Activity and expression level of the enzyme were significantly increased under oxidative stressed conditions. These results collectively suggest that AcFe-SOD may play essential roles in the survival of the parasite not only by protecting itself from endogenous oxidative stress but also by detoxifying oxidative killing of the parasite by host immune effector cells.
- Subjects :
- Acanthamoeba castellanii genetics
Amino Acid Sequence
Cell Survival
Cloning, Molecular
Coenzymes metabolism
Conserved Sequence
Enzyme Inhibitors metabolism
Enzyme Stability
Gene Expression Profiling
Humans
Hydrogen Peroxide metabolism
Hydrogen-Ion Concentration
Introns
Molecular Sequence Data
Oxidative Stress
Protein Binding
Protein Conformation
Recombinant Proteins chemistry
Recombinant Proteins genetics
Recombinant Proteins metabolism
Sequence Alignment
Superoxide Dismutase chemistry
Acanthamoeba castellanii enzymology
Gene Expression
Iron metabolism
Superoxide Dismutase genetics
Superoxide Dismutase metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1432-1955
- Volume :
- 111
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Parasitology research
- Publication Type :
- Academic Journal
- Accession number :
- 22752747
- Full Text :
- https://doi.org/10.1007/s00436-012-3006-7