Thioredoxins are a class of low molecular weight redox proteins that undergo reversible reduction-oxidation of two active-site cysteine residues with reduction catalyzed by the NADPH-dependent flavoenzyme thioredoxin reductase. Human thioredoxin has been shown to be identical to a previously reported leukemic cell growth factor. We now report that recombinant human thioredoxin added to minimal ...

Thioredoxin reductase (EC l&4.5), which catalyzes the reduction of the disulfide bridge in thioredoxin by NADPH, was purified from calf liver and thymus. Preparation methods, involving chromatography on DEAE-cellulose, TEAEcellulose, and Sephadex G-200 or G-100 were used to purify the calf liver enzyme llOO-fold and the thymus enzyme 2800fold. The enzyme was shown to catalyze an NADPH-dependent...

BACKGROUND AND OBJECTIVES The redox-regulatory protein thioredoxin has several functions including transcriptional regulation, and antioxidant, cytokine, and chemokine activities. We have previously shown that extracellular thioredoxin protects B-cell chronic lymphocytic leukemia (CLL) cells from apoptosis in vitro. In this study we were interested to determine whether thioredoxin is produced b...

and have a tendency to aggregate, indicating that formation of a second disulphide in the molecule is accompanied by denaturation of the structure. Reduction of oxidized thymus thioredoxin can be achieved by dithiothreitol or by NADPH and thioredoxin reductase representing a possible autocatalytic control mechanism. Another major difference between the mammalian and the E. coli thioredoxin syst...

Escherichia coli B contains a cytidine diphosphate reductase system which utilizes reduced triphosphopyridine nucleotide to effect the reduction of cytidine diphosphate to deoxycytidine diphosphate (1, 2). Two components, thioredoxin and thioredoxin reductase, have been identified as oxidation-reduction carriers between TPNH and cytidine diphosphate. Thioredoxin is a low molecular weight protei...

Activity of the cysteine adducts of the cysteine proteinases papain and thaumatopain can be recovered by treatment with thioredoxin, thioredoxin reductase and NADPH. Recovery of proteinase activity did not occur if any of the components of the thioredoxin system were omitted, or if thioredoxin or thioredoxin reductase were heat-inactivated. Such an enzyme-mediated process may be of significance...

The thioredoxin system plays an important role in maintaining a reducing environment in the cell. Recently, several thioredoxin binding partners have been identified and proposed to mediate aspects of redox signaling, but the significance of these interactions is unclear in part due to incomplete understanding of the mechanism for thioredoxin binding. Thioredoxin-interacting protein (Txnip) is ...

The cytosolic thioredoxin redox system composed of thioredoxin-1 and the NADPH-dependent thioredoxin reductase-1 reductase is an important regulator of cell growth and survival. Thioredoxin-1 is overexpressed in many human tumors where it is associated with increased cell proliferation, decreased apoptosis, and decreased patient survival. We hypothesized that thioredoxin reductase-1 provides a ...

In addition to the standard NADPH thioredoxin reductases (NTRs), plants hold a plastidic NTR (NTRC), with a thioredoxin module fused at the C-terminus. NTRC is an efficient reductant of 2-Cys peroxiredoxins (2-Cys Prxs). The interaction of NTRC and chloroplastic thioredoxin x with 2-Cys Prxs has been confirmed in vivo, by bimolecular fluorescence complementation (BiFC) assays, and in vitro, by ...

Nicotinamide cofactor-dependent oxidoreductases have become a valuable tool for the synthesis of high value chiral compounds. The feasibility biocatalytic processes involving these enzymes stands and falls with efficiency regeneration cofactors. In this study, we describe novel NADPH method based on natural thioredoxin electron delivery system. Thioredoxin 1 (Trx1) reductase (TR) from Thermus t...