It has been demonstrated that susceptibility to glucocorticoid-induced formation of cleft palate is regulated by the mouse histocompatibility complex (H-2). This has encouraged us to examine H-2 effects on glucocorticoid binding in tissues of adult animals which would provide sufficient material with which to study the biochemical mechanism of the H-2 effect. Although it has been reported that ...

The kinetics of thiol modulation of the chloroplast H+-ATPase (CF0CF1) in membrana were analyzed by employing thioredoxins that were kept reduced by 0.1 mM dithiothreitol. The kinetics of thiol modulation depend on the extent of the proton gradient. The process is an exponential function of the thioredoxin concentration and reaction time and can be described by an irreversible second order reac...

Gliadins and glutenins, the major storage proteins of wheat endosperm (Triticum durum, Desf. cv Monroe), were reduced in vitro by the NADP/thioredoxin system (NADPH, NADP-thioredoxin reductase and thioredoxin; in plants, the h type) from either the same source or the bacterium Escherichia coli. A more limited reduction of certain members of these protein groups was achieved with the reduced fo...

Oxidative stress is a key feature in the pathogenesis of pre-eclampsia and antioxidants have been proposed as a potential therapy in the treatment of this important complication of pregnancy. In this report selenium supplementation was used to up-regulate the antioxidant enzymes glutathione peroxidase and thioredoxin reductase and the protective effect that this had on cellular metabolism durin...

Unlike other thioredoxins h characterized so far, a poplar thioredoxin of the h type, PtTrxh4, is reduced by glutathione and glutaredoxin (Grx) but not NADPH:thioredoxin reductase (NTR). PtTrxh4 contains three cysteines: one localized in an N-terminal extension (Cys(4)) and two (Cys(58) and Cys(61)) in the classical thioredoxin active site ((57)WCGPC(61)). The property of a mutant in which Cys(...

Thioredoxin h (Trxh) is a ubiquitous protein that reduces disulfides in target proteins, and is itself reduced by NADPH-thioredoxin reductase. In the current study, the complementary DNA sequence and the genomic sequence of the three-pistil (TP) line of common wheat (Triticum aestivum L.) were obtained from spikes through reverse transcription-polymerase chain reaction (RT-PCR) and touchdown-PC...

The glycine-utilizing bacterium Clostridium litoralis contained two enzyme systems for oxidizing dihydrolipoamide. The first one was found to be a genuine dihydrolipoamide dehydrogenase, present only in low amounts. This enzyme had the typical dimeric structure with a subunit molecular mass of about 53 kDa; however, it reacted with both NADP (Km 0.11 mM) and NAD (Km 0.5 mM). The reduction of py...

The AtTRXh5 protein belongs to the cytosolic thioredoxins h family that, in Arabidopsis, contains eight members showing very distinct patterns and levels of expression. Here, we show that the AtTRXh5 gene is up-regulated during wounding, abscission, and senescence, as well as during incompatible interactions with the bacterial pathogen Pseudomonas syringae. By electrophoretic mobility shift ass...

The thioredoxin system, comprising thioredoxin (Trx), thioredoxin reductase (TrxR) and NADPH, is one of the major cellular antioxidant systems, implicated in a large and growing number of biological functions. Trx acts as an oxidoreductase via a highly conserved dithiol/disulfide motif located in the active site ( Trp-Cys-Gly-Pro- Cys-Lys-). Different factors are involved in the regulation of T...

Glu85 in the Escherichia coli thioredoxin, which is localized in the loop between beta4 and beta5, was substituted with the Arg present in the corresponding position in Bacillus acidocaldarius thioredoxin. This suggested that it could play an important role in the structure and thermostability of this protein owing to its involvement in numerous interactions. The effects of the mutation on the ...