Reversible thiol/disulfide exchange equilibria between rabbit muscle phosphofructokinase and glutathione redox buffers results in a dependence of the activity of the enzyme on the thiol to disulfide ratio of the redox buffer (Gilbert, H. F. (1982) J. Biol. Chem. 257, 12086-12091). The transition between fully reduced (active) and fully oxidized (inactive) enzyme is half complete at a [GSH]/[GSS...

The retro-analogue of glutathione disulfide was bound to the GSSG binding site of crystalline glutathione reductase. The binding mode revealed why the analogue is a very poor substrate in enzyme catalysis. The observed binding mode difference between natural substrate and retro-analogue is explained.

Glutathione disulfide (GSSG) is the oxidized form of glutathione (GSH). GSH is a tripeptide present in the biological system in mM concentration and is the major antioxidant in the body. An increase in GSSG reflects an increase in intracellular oxidative stress and is associated with disease sates. The increase has also been demonstrated to lead to an increase in protein S-glutathionylation tha...

Measurement of glutathione (GSH) and glutathione disulfide (GSSG) is a crucial tool to assess cellular redox state. Herein we report a direct approach to determine intracellular GSH based on a rapid chromatographic separation coupled with acidic potassium permanganate chemiluminescence detection, which was extended to GSSG by incorporating thiol blocking and disulfide bond reduction. Importantl...

Cancer metastasis is the major cause of cancer mortality. Despite extensive research efforts, effective treatment for cancer metastasis is still lacking. Cancer metastasis involves 4 essential steps: cell detachment, migration, invasion, and adhesion. Detachment is the first and required step for metastasis. Glutathione disulfide (GSSG) is derived from the oxidation of glutathione (GSH), which ...

A 2D imaging system using closed bipolar electrodes (cBPEs) and electrochemiluminescence (ECL) is expected to realize high spatio-temporal resolution imaging. However, of the distributions molecules that cause an oxidation reaction on electrode surface was not achieved by cBPE/ECL because conventionally used luminophore can generate ECL only reaction. In this paper, we propose implement a catho...

Rabbit muscle phosphofructokinase is rapidly inactivated at pH 8.0 by incubation with low concentrations of oxidized glutathione, Coenzyme A glutathione mixed disulfide, and oxidized Coenzyme A. The inactivation is first order in disulfide concentration over the concentration ranges examined (50-200 microM), and is approximately 8-fold slower at pH 7.0 than at pH 8.0. The substrates ATP and fru...

Exposure of the lung epithelium to reactive oxygen species without adequate antioxidant defenses leads to airway inflammation, and may contribute to lung injury. Glutathione peroxidase catalyzes the reduction of peroxides by oxidation of glutathione (GSH) to glutathione disulfide (GSSG), which can in turn be reduced by glutathione reductase (GR). Increased levels of GSSG have been shown to corr...

Mitochondrial thioredoxin-glutathione reductase was purified from larval Taenia crassiceps (cysticerci). The preparation showed NADPH-dependent reductase activity with either thioredoxin or GSSG, and was able to perform thiol/disulfide exchange reactions. At 25 degrees C specific activities were 437 +/- 27 mU mg(-1) and 840 +/- 49 mU mg(-1) with thioredoxin and GSSG, respectively. Apparent K(m)...

Both the lethal and the mutagenic actions of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) on cells of Streptococcus pneumoniae were greatly potentiated by a component of yeast extract added to the cellular environment. This component was found to be an oxidation product of glutathione, glutathione disulfide (GSSG). At low concentrations in the medium, both GSSG and glutathione potentiated MNNG a...