The 2.2 A crystalline structure of an oxidized active-site variant of Escherichia coli thioredoxin (Trx) has been solved. Trx is a 12 kDa enzyme which catalyzes the oxidation of dithiols and the reduction and isomerization of disulfides in other proteins. Its active site contains the common structural motif CXXC. Protein-disulfide isomerase (PDI), a 57 kDa homolog of Trx, contains four Trx-like...

Forty years ago, ferredoxin (Fdx) was shown to activate fructose 1,6-bisphosphatase in illuminated chloroplast preparations, thereby laying the foundation for the field now known as "redox biology." Enzyme activation was later shown to require the ubiquitous protein thioredoxin (Trx), reduced photosynthetically by Fdx via an enzyme then unknown-ferredoxin:thioredoxin reductase (FTR). These prot...

Cysteine residues in cytosolic proteins are maintained in their reduced state, but can undergo oxidation owing to posttranslational modification during redox signaling or under conditions of oxidative stress. In large part, the reduction of oxidized protein cysteines is mediated by a small 12-kDa thiol oxidoreductase, thioredoxin (Trx). Trx provides reducing equivalents for central metabolic en...

BACKGROUND Parathyroid hormone is an 84-amino acid peptide secreted by the parathyroid glands. Its physiological role is maintenance of normal serum calcium level and bone remodeling. Biological activity of this hormone is related to N-terminal 1-34 amino acids. The recombinant form of hormone (1-34) has been approved for treatment of osteoporosis from 2002. In this study, a novel fusion partne...

Thioredoxin (Trx) reduces disulfide bonds and play numerous important functions in plants. In cereal seeds, cytosolic h-type Trx facilitates the release of energy reserves during the germination process and is recycled by NADPH-dependent Trx reductase. This review presents a summary of the research conducted during the last 10 years to elucidate the structure and function of the barley seed Trx...

background and aims: ndv (newcastle disease virus) is one of the viruses that cause disease in avian with severe economic losses in the poultry industry in many countries. fusion protein (f) which plays a major role in the virus pathogenicity contains several regions that have a role in the fusion process. mutation in the sequence of hr1 & hr2 regions of this protein prevents fusion of the viru...

We introduce three assays for analyzing ligand-receptor interactions based on the specific conjugation of ligands to SNAP-tag fusion proteins. Conjugation of ligands to different SNAP-tag fusions permits the validation of suspected interactions in cell extracts and fixed cells as well as the establishment of high-throughput assays. The different assays allow the analysis of strong and weak inte...

All organisms contain thioredoxin (TRX), a regulatory thiol:disulfide protein that reduces disulfide bonds in target proteins. Unlike animals and yeast, plants contain numerous TRXs for which no function has been assigned in vivo. Recent in vitro proteomic approaches have opened the way to the identification of >100 TRX putative targets, but of which none of the numerous plant TRXs can be speci...

Thioredoxin (Trx) is a cytosolic, redox-active protein that is secreted from many cells and has several extracellular functions. In activated lymphocytes, the pathway of secretion does not involve the Golgi apparatus. Levels of extracellular Trx are decreased by the antioxidant N-acetylcysteine. Hence, the secretion of Trx could be altered by the redox status of the cell or the protein. To stud...

Mitochondria contain thioredoxin (Trx), a regulatory disulfide protein, and an associated flavoenzyme, NADP/Trx reductase, which provide a link to NADPH in the organelle. Unlike animal and yeast counterparts, the function of Trx in plant mitochondria is largely unknown. Accordingly, we have applied recently devised proteomic approaches to identify soluble Trx-linked proteins in mitochondria iso...