AUTHOR=Hai Xunan , Zhang Houshuang , Wang Zhonghua , Gong Haiyan , Cao Jie , Zhou Yongzhi , Zhou Jinlin 

TITLE=Identification of 2-Cys Peroxiredoxin (BmTPx-2) as Antioxidant Active Molecule from Babesia microti

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.01959

DOI=10.3389/fmicb.2017.01959

ISSN=1664-302X

ABSTRACT=<p>Peroxiredoxins (Prxs) are a family of antioxidant enzymes that reduce peroxides in the presence of thioredoxin, thioredoxin reductase, and nicotinamide adenine dinucleotide phosphate (NADPH) to resist oxidative stress. In this study, we identified and isolated a 2-Cys Prx designated as ‘<italic>BmTPx-2</italic>’ from <italic>Babesia microti</italic>, with a full-length cDNA of 826 bp and an open reading frame of 756 bp, which encodes a 251-amino acid protein. BLAST analysis demonstrated that BmTPx-2 shows the typical features of members of the 2-Cys Prx family, which includes harboring two conserved VCP motifs with Cys<sup>101</sup> and Cys<sup>221</sup> conserved cysteine residues. Recombinant BmTPx-2 was expressed in <italic>Escherichia coli</italic> and analyzed by western blot. The antioxidant activity of BmTPx-2 was demonstrated using a mixed-function oxidation system and oxidation of NADPH. Furthermore, <italic>BmTPx-2</italic> mRNA expression level in parasites at the erythrocytes and tick stages were analyzed by real-time fluorescence quantitative PCR. Peak <italic>BmTPx-2</italic> mRNA transcription was detected 8 days after infection at the erythrocyte stage, but not at the tick stage. Taken together, this study characterized <italic>BmTPx-2</italic> from <italic>B. microti</italic> as an antioxidant molecule that was specifically transcribed at the erythrocyte stage.</p>