Identification and characterization of a mitochondrial iron-superoxide dismutase of Cryptosporidium parvum.
Cryptosporidium parvum is an intracellular protozoan parasite that causes cryptosporidiosis in mammals. In this study, we identified a gene encoding mitochondrial iron-superoxide dismutase of C. parvum (Cp-mtSOD) and characterized biochemical properties of the recombinant protein. Multiple sequence alignment of the deduced amino acid sequence of Cp-mtSOD with those of previously reported iron-containing SODs (Fe-SODs) from other protozoan parasites showed that Cp-mtSOD shares common metal-binding residues and motifs that were conserved in Fe-SODs. However, the N-terminal 26-amino acid residues of Cp-mtSOD did not show sequence identities to any other Fe-SOD sequences. Further analysis of the N-terminal presequence of Cp-mtSOD suggested that it shares common physiochemical characteristics found in mitochondria targeting sequences and predicted localization of Cp-mtSOD in the mitochondria. The recombinant Cp-mtSOD showed typical biochemical properties with other characterized Fe-SODs, including molecular structure, broad pH optimum, and sensitivity to hydrogen peroxide.
Kang
Jung-Mi
JM
Department of Parasitology and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, 660-751, South Korea.
Cheun
Hyeng-Il
HI
Kim
Juri
J
Moon
Sung-Ung
SU
Park
Soon-Jung
SJ
Kim
Tong-Soo
TS
Sohn
Woon-Mok
WM
Na
Byoung-Kuk
BK
D020816:Amino Acid Motifs; D000818:Animals; D001665:Binding Sites; D003001:Cloning, Molecular; D017124:Conserved Sequence; D016785:Cryptosporidium parvum / Q000201:enzymology* / Q000235:genetics*; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004795:Enzyme Stability; D006861:Hydrogen Peroxide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D021382:Protein Sorting Signals; D017433:Protein Structure, Secondary; D021381:Protein Transport; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013482:Superoxide Dismutase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
D016054:DNA, Protozoan; D004791:Enzyme Inhibitors; D024101:Mitochondrial Proteins; D021382:Protein Sorting Signals; D015800:Protozoan Proteins; D011994:Recombinant Proteins; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase