Hypoprothrombinemia is a serious adverse effect of antimicrobial therapy that occurs after administration of some second- and third-generation cephalosporins which contain the methyltetrazole-thiol (MTT) group. Previous studies have shown that in vitro MTT directly inhibits microsomal gamma-carboxylation of a synthetic pentapeptide. Since MTT is a thiocarbamide, a type of compound that can incr...

Glutathione is present in millimolar concentrations in the cell, but its relative distribution among cellular compartments remains elusive. We have chosen the endoplasmic reticulum (ER) as an example organelle to study compartment-specific glutathione levels. Using a glutaredoxin sensor (sCGrx1pER), which rapidly and specifically equilibrates with the reduced glutathione (GSH)-glutathione disul...

Glutathione disulfide (GSSG) is an endogenous peptide and the oxidized form of glutathione. The impacts of GSSG on cell function/dysfunction remain largely unexplored due to a lack of method to specifically increase intracellular GSSG. We recently developed GSSG liposomes that can specifically increase intracellular GSSG. The increase affected 3 of the 4 essential steps (cell detachment, migrat...

Glutathione is present in millimolar concentrations in the cell, but its relative distribution among cellular compartments remains elusive. We have chosen the endoplasmic reticulum (ER) as an example organelle to study compartment-specific glutathione levels. Using a glutaredoxin sensor (sCGrx1pER), which rapidly and specifically equilibrates with the reduced glutathione (GSH)–glutathione disul...

The status of glutathione in the liver of male rats as a function of their age and acute stress was investigated. Total glutathione (TG), which is measured after the reduction of liver homogenate with NaBH4 , reduced glutathione (GSH) and disulfide glutathione (GSSG) increase with advancing age of the test animals (weights from 15 g to 350 g). The mixed glutathione disulfides [XSSG = TG— (GSH +...

This studies whether the water extract of Osmanthus fragrans can prevent noise-induced hearing loss (NIHL) after exposure to a noisy environment. Twenty-four healthy factory workers in southern Taiwan were recruited. The hearing threshold was determined before and after each dosing period. Measurements of oxygen radical absorbance capacity (ORAC), glutathione (GSH), oxidized glutathione disulfi...

Thimet oligopeptidase (EP24.15) is a cysteine-rich metallopeptidase containing fifteen Cys residues and no intra-protein disulfide bonds. Previous work on this enzyme revealed that the oxidative oligomerization of EP24.15 is triggered by S-glutathiolation at physiological GSSG levels (10-50 µM) via a mechanism based on thiol-disulfide exchange. In the present work, our aim was to identify EP24....

We previously reported a computer model of the human erythrocyte using E-CELL simulation system [1, 2]. The model has three major metabolic pathways, including glycolysis, the pentose phosphate pathway, and nucleotide metabolism, as well as Na+/K+ pumps, some transport systems, and magnesium complexation. All kinetic parameters for enzymes were based on the experimental data published in the li...

The flavin-dependent monooxygenase from yeast (yFMO) oxidizes biological thiols such as cysteine, cysteamine, and glutathione. The enzyme makes a major contribution to the pools of oxidized thiols that, together with reduced glutathione from glutathione reductase, create the optimum cellular redox environment. We show that the activity of yFMO, as a soluble enzyme or in association with the ER ...

This paper reports inhibition of Na(+) + K(+)-stimulated, ouabain-inhibited adenosine triphosphatase (S-ATPase) in sheep red cell membranes by oxidized glutathione (GSSG). The results are consistent with the hypothesis that this inhibition depends upon the formation of a mixed disulfide between glutathione and -SH group(s) in the enzyme protein. Thus, inhibition of S-ATPase by GSSG proceeds mor...