title: Identification and characterization of an atypical 2-cys peroxiredoxin from the silkworm, Bombyx mori.
abstract: Peroxiredoxins (Prxs) play an important role in the protection of insects against the toxicity of reactive oxygen species. Here, we identified and characterized a novel, atypical 2-cysteine (Cys) peroxiredoxin (BmPrx3) from an expressed sequence tag database in a lepidopteran insect, Bombyx mori. The BmPrx3 cDNA contained an open reading frame of 684 bp that encodes a 228-amino-acid protein with a calculated molecular mass of 25 kDa. Sequence comparison revealed that BmPrx3 belongs to the atypical 2-Cys Prxs. Quantitative real-time PCR revealed that BmPrx3 can be detected in all tissues and developmental stages. Recombinant BmPrx3 purified from Escherichia coli exhibited antioxidant activity that removed hydrogen peroxide and protected DNA from oxidative damage. Disc diffusion and viability assays revealed that recombinant BmPrx3 increased bacterial survival under H2 O2 -mediated oxidative stress. In addition, quantitative real-time PCR analysis indicated that BmPrx3 transcription levels were significantly increased in response to various oxidative stresses. Furthermore, BmPrx3 transcription levels in the midgut were regulated by bacterial infection. Taken together, these results suggest that BmPrx3 acts as an antioxidant enzyme to protect the silkworm from various oxidative stresses.
authors.affiliation: Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, China.
authors.forename: K
authors.initials: K
authors.lastname: Chen
authors.affiliation: School of Medicine, Jiangsu University, Zhenjiang, China.
authors.forename: X
authors.initials: X
authors.lastname: Ju
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D003001:Cloning, Molecular; D003545:Cysteine / Q000737:chemistry; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D007814:Larva / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D054464:Peroxiredoxins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D018076:DNA, Complementary; D019476:Insect Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D054464:Peroxiredoxins; D003545:Cysteine
keywords: Bombyx mori; antioxidant activity; oxidative stress; peroxiredoxin 3