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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
12
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pubmed:dateCreated |
1996-7-25
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pubmed:abstractText |
The possible relationship of selenium to immunological function which has been suggested for decades was investigated in studies on selenium metabolism in human T cells. One of the major 75Se-labeled selenoproteins detected was purified to homogeneity and shown to be a homodimer of 55-kDa subunits. Each subunit contained about 1 FAD and at least 0.74 Se. This protein proved to be thioredoxin reductase (TR) on the basis of its catalytic activities, cross-reactivity with anti-rat liver TR antibodies, and sequence identities of several tryptic peptides with the published deduced sequence of human placental TR. Physicochemical characteristics of T-cell TR were similar to those of a selenocysteine (Secys)-containing TR recently isolated from human lung adenocarcinoma cells. The sequence of a 12-residue 75Se-labeled tryptic peptide from T-cell TR was identical with a C-terminal-deduced sequence of human placental TR except that Secys was present in the position corresponding to TGA, previously thought to be the termination codon, and this was followed by Gly-499, the actual C-terminal amino acid. The presence of the unusual conserved Cys-Secys-Gly sequence at the C terminus of TR in addition to the redox active cysteines of the Cys-Val-Asn-Val-Gly-Cys motif in the FAD-binding region may account for the peroxidase activity and the relatively low substrate specificity of mammalian TRs. The finding that T-cell TR is a selenoenzyme that contains Se in a conserved C-terminal region provides another example of the role of selenium in a major antioxidant enzyme system (i.e., thioredoxin-thioredoxin reductase), in addition to the well-known glutathione peroxidase enzyme system.
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-1066676,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-1538779,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-1569062,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-1825132,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-1828528,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-1832744,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-194234,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-2188973,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-2501514,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-6950391,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-7159551,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-7476354,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-7476373,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-7589432,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-7744824,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-7876079,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-8194133,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-8274532,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-8278371,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-8287546,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-8343516,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-8349599,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-8555176,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-8577704,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-8600838,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8650234-8722124
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Jun
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pubmed:issn |
0027-8424
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
11
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pubmed:volume |
93
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
6146-51
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
pubmed-meshheading:8650234-Amino Acid Sequence,
pubmed-meshheading:8650234-Animals,
pubmed-meshheading:8650234-Base Sequence,
pubmed-meshheading:8650234-Codon,
pubmed-meshheading:8650234-Humans,
pubmed-meshheading:8650234-Molecular Sequence Data,
pubmed-meshheading:8650234-Placenta,
pubmed-meshheading:8650234-Selenocysteine,
pubmed-meshheading:8650234-Sequence Homology, Amino Acid,
pubmed-meshheading:8650234-Spectrometry, Mass, Matrix-Assisted Laser...,
pubmed-meshheading:8650234-T-Lymphocytes,
pubmed-meshheading:8650234-Thioredoxin-Disulfide Reductase
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pubmed:year |
1996
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pubmed:articleTitle |
Selenocysteine, identified as the penultimate C-terminal residue in human T-cell thioredoxin reductase, corresponds to TGA in the human placental gene.
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pubmed:affiliation |
Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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pubmed:publicationType |
Journal Article
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