title: Characterization of gamma radiation inducible thioredoxin h from Spirogyra varians.
abstract: In this study, thioredoxin h (Trxh) was isolated and characterized from the fresh water green alga Spirogyra varians, which was one amongst the pool of proteins induced upon gamma radiation treatment. cDNA clones encoding S. varians thioredoxin h were isolated from a pre-constructed S. varians cDNA library. Trxh had a molecular mass of 13.5kDa and contained the canonical WCGPC active site. Recombinant Trxh showed the disulfide reduction activity, and exhibited insulin reduction activity. Also, Trxh had higher 5,5'-dithiobis(2-nitrobenzoic acid) reduction activity with Arabidopsis thioredoxin reductase (TR) than with Escherichia coli TR. Specific expression of the Trxh gene was further analyzed at mRNA and protein levels and was found to increase by gamma irradiation upto the absorbed dose of 3kGy, suggesting that Trxh may have potential functions in protection of biomolecules from gamma irradiation.
authors.affiliation: Korea Atomic Energy Research Institute, Advanced Radiation Technology Institute, Jeongeup 580-185, South Korea.
authors.forename: Minchul
authors.initials: M
authors.lastname: Yoon
authors.forename: Ho-Yeon
authors.initials: HY
authors.lastname: Yang
authors.forename: Seung-Sik
authors.initials: SS
authors.lastname: Lee
authors.forename: Dong-Ho
authors.initials: DH
authors.lastname: Kim
authors.forename: Gwang-Hoon
authors.initials: GH
authors.lastname: Kim
authors.forename: Jong-il
authors.initials: JI
authors.lastname: Choi
mesh_terms: D020418:Algal Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000528:radiation effects*; D000595:Amino Acid Sequence; D001483:Base Sequence; D048028:DNA, Algal / Q000235:genetics; D015870:Gene Expression / Q000528:radiation effects; D008969:Molecular Sequence Data; D010802:Phylogeny; D020543:Proteome / Q000528:radiation effects; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D058131:Spirogyra / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects*; D054480:Thioredoxin h / Q000096:biosynthesis* / Q000235:genetics / Q000528:radiation effects*
chemical_list: D020418:Algal Proteins; D048028:DNA, Algal; D020543:Proteome; D011994:Recombinant Proteins; D054480:Thioredoxin h
keywords: Radiation protection; Reduction assay; Spirogyra varians; Thioredoxin