title: Cloning, expression and antioxidant activity of a thioredoxin peroxidase from Branchiostoma belcheri tsingtaunese.
abstract: Peroxiredoxins (Prxs) are ubiquitous antioxidant enzymes that catalyze the thioredoxin- dependent reduction of hydroperoxides. In this study, a novel thioredoxin peroxidase (Bbt-TPx1), a member of the peroxiredoxin superfamily, was found by EST sequence analysis of a cDNA library of Branchiostoma belcheri tsingtaunese ovary. The sequence of a full-length cDNA clone contained an open reading frame encoding a polypeptide of 198 amino acid residues, with a calculated molecular weight of 22,150 Da. The expression patterns of the protein at different developmental stages and adult amphioxus tissues indicate that this enzyme may play important roles in anti-oxidation and innate immunity. The recombinant Bbt-TPx1 protein was expressed with a polyhistidine-tag in Escherichia coli and purified using Ni chromatography followed by SP cation exchange chromatography. The rBbt-TPx1 protein existed as a dimer under non-reducing conditions, and was dissociated into monomers by dithiothreitol (DTT); it might predominantly exist in oligomeric form. The rBbt-TPx1 protein showed a significant thiol-dependent peroxidase activity, removing hydrogen peroxide in the presence of dithiothreitol (DTT), but not glutathione (GSH). Protection of plasmid DNA and the thiol-protein from damage by metal-catalyzed oxidation (MCO) in vitro was also revealed.
authors.affiliation: Institute for Laboratory Medicine, Fuzhou General Hospital of Nanjing Command, Fuzhou, Fujian Province, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Liao
authors.affiliation: Institute for Laboratory Medicine, Fuzhou General Hospital of Nanjing Command, Fuzhou, Fujian Province, China.
authors.forename: Kaiyu
authors.initials: K
authors.lastname: Wang
authors.affiliation: Clinical Laboratory, The First Hospital of Longhai, Zhangzhou, Fujian Province, China.
authors.forename: Weirong
authors.initials: W
authors.lastname: Yao
authors.affiliation: Institute for Laboratory Medicine, Fuzhou General Hospital of Nanjing Command, Fuzhou, Fujian Province, China.
authors.forename: Xunfei
authors.initials: X
authors.lastname: Yi
authors.affiliation: Institute for Laboratory Medicine, Fuzhou General Hospital of Nanjing Command, Fuzhou, Fujian Province, China.
authors.forename: Huihui
authors.initials: H
authors.lastname: Yan
authors.affiliation: Institute for Laboratory Medicine, Fuzhou General Hospital of Nanjing Command, Fuzhou, Fujian Province, China.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.affiliation: Institute for Laboratory Medicine, Fuzhou General Hospital of Nanjing Command, Fuzhou, Fujian Province, China.
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Lan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001483:Base Sequence; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D064175:Lancelets / Q000145:classification / Q000201:enzymology*; D016366:Open Reading Frames; D054464:Peroxiredoxins / Q000378:metabolism*; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
chemical_list: D000975:Antioxidants; D054464:Peroxiredoxins