NOTE Parasitology Cloning and Characterization of a 2-Cys Peroxiredoxin from Babesia gibsoni

ABSTRACT. Peroxiredoxins (Prxs) are a family of antioxidant enzymes. Here, we cloned a 2-Cys Prx, BgTPx-1, from the canine Babesia parasite B. gibsoni. Sequence identity between BgTPx-1 and 2-Cys Prx of B. bovis was 81 % at the amino acid level. Enzyme activity assay by using recombinant BgTPx-1 (rBgTPx-1) indicated that BgTPx-1 has antioxidant activity. Antiserum from a mouse immunized with rBgTPx-1 reacted with parasite lysates and detect a protein with a monomeric size of 22 kDa and also a 44 kDa protein, which might be an inefficiently reduced dimer. BgTPx-1 was expressed in the cytoplasm of B. gibsoni merozoites. These results suggest that the BgTPx-1 may play a role to control redox balance in the cytoplasm of B. gibsoni. KEY WORDS: antioxidant activity, Babesia gibsoni, canine, peroxiredoxin. doi: 10.1292/jvms.13-0274; J. Vet. Med. Sci. 76(1): 139–143, 2014 Babesia gibsoni is a tick-borne intraerythrocytic apicom-plexan parasite that causes piroplasmosis in dogs [5, 10]. The disease is characterized by remittent fever, progres-sive anemia, marked splenomegaly and hepatomegaly and sometimes causes death [9]. B. gibsoni infection is endemic in many regions of Asia, Africa, Europe and Americas [18]. Generally, B. gibsoni infection is characterized by recurren