Semisynthesis and Characterization of Mammalian Thioredoxin Reductase†

Semisynthesis and characterization of mammalian thioredoxin reductase.

Thioredoxin reductase and thioredoxin constitute the cellular thioredoxin system, which provides reducing equivalents to numerous intracellular target disulfides. Mammalian thioredoxin reductase contains the rare amino acid selenocysteine. Known as the "21st" amino acid, selenocysteine is inserted into proteins by recoding UGA stop codons. Some model eukaryotic organisms lack the ability to ins...

Mammalian Selenoprotein Thioredoxin-glutathione Reductase

Cloning of thioredoxin h reductase and characterization of the thioredoxin reductase-thioredoxin h system from wheat.

Thioredoxins h are ubiquitous proteins reduced by NADPH- thioredoxin reductase (NTR). They are able to reduce disulphides in target proteins. In monocots, thioredoxins h accumulate at high level in seeds and show a predominant localization in the nucleus of seed cells. These results suggest that the NTR-thioredoxin h system probably plays an important role in seed physiology. To date, the study...

Selenodiglutathione is a highly efficient oxidant of reduced thioredoxin and a substrate for mammalian thioredoxin reductase.

Selenium compounds like selenite (SeO3(2-) may form a covalent adduct with glutathione (GSH) in the form of selenodiglutathione (GS-Se-SG), which is assumed to be important in the metabolism of selenium. We have isolated GS-Se-SG and studied its reactions with NADPH and thioredoxin reductase from calf thymus or with thioredoxin reductase and thioredoxin from Escherichia coli. Incubation of 0.1 ...

Molecular characterization of thioredoxin-1 and thioredoxin reductase activity in mud crab Scylla paramamosain.

The thioredoxin (Trx) system consists of thioredoxin reductase (TrxR), Trx, and nicotinamide adenine dinucleotide phosphate (NADPH). TrxR is an NADPH-dependent oxidoreductase. Trx is a ubiquitous small protein with a redox-active disulfide bridge that plays important regulatory roles in some vital metabolic reactions. In this study, a cDNA sequence (SpTrx1) showing high identity to the first Tr...