Thioredoxin reduces disulfide bonds, thus regulating activities of target proteins in various biological systems, e.g., inactivation of inhibitors of starch hydrolases and proteases in germinating plant seeds. In the three-dimensional structure of a complex with barley α-amylase/subtilisin inhibitor (BASI), two loops in barley thioredoxin h2 (HvTrxh2), containing an invariant cis-proline ((86)E...

Virgin, pregnant, and lactating rats were used to assess the influence of selenomethionine and selenocystine, fed at four to seven times the daily Se requirement (supranutritional), on Se load and selenoprotein activities. Female Sprague Dawley rats (n = 48; age = 13 wk), reared on a low-Se torula yeast diet, were assigned to one of three reproductive states (n = 16 per reproductive state) to o...

Mammalian thioredoxin reductases are selenoproteins. For native catalytic activity, these enzymes utilize a C-terminal -Gly-Cys-Sec-Gly-COOH sequence (where Sec is selenocysteine) forming a redox active selenenylsulfide/selenolthiol motif. A range of cellular systems depend upon or are regulated by thioredoxin reductase and its major protein substrate thioredoxin, including apoptosis signal-reg...

O status (redox) is an important regulator of various metabolic functions of the cell. Perturbations in the redox status of cells by external or internal stimuli elicit distinct responses, resulting in alteration of cell function. Glutathione and thioredoxin are two major reducing systems of the eukaryotic cell that maintain redox balance, as well as interact with various transducer and effecto...

The indolequinone ES936 {5-methoxy-1,2-dimethyl-3-[(4-nitrophenoxy)methyl]indole-4,7-dione} was previously developed in our lab as an antitumor agent against pancreatic cancer. The objective of this study was to identify indolequinones with improved potency against pancreatic cancer and to define their mechanisms of action. Pancreatic cancer cell lines PANC-1, MIA PaCa-2, and BxPC-3 were used i...

Plant chloroplasts have versatile thioredoxin systems including two thioredoxin reductases and multiple types of thioredoxins. Plastid-localized NADPH-dependent thioredoxin reductase (NTRC) contains both reductase (NTRd) and thioredoxin (TRXd) domains in a single polypeptide and forms homodimers. To study the action of NTRC and NTRC domains in vivo, we have complemented the ntrc knockout line o...

Introduction The flavoprotein disulphide oxidoreductases constitute a growing family of homologous dimeric enzymes, with an important and diverse range of functions in vivo. Among its members are dihydrolipoyl dehydrogenase, glutathione reductase, mercuric reductase, thioredoxin reductase, trypanothione reductase and a related enzyme, NADPH peroxidase (for recent reviews of their structures and...