Glutathione S-transferase omega in the lung and sputum supernatants of COPD patients.

Background: The major contribution to oxidant related lung damage in COPD is from the oxidant/antioxidant imbalance and possibly impaired antioxidant defence. Glutathione (GSH) is one of the most important antioxidants in human lung and lung secretions, but the mechanisms participating in its homeostasis are partly unclear. Glutathione-S-transferase omega (GSTO) is a recently characterized cysteine containing enzyme with the capability to bind and release GSH in vitro.

Modulation of glutaredoxin in the lung and sputum of cigarette smokers and chronic obstructive pulmonary disease.

Background: One typical feature in chronic obstructive pulmonary disease (COPD) is the disturbance of the oxidant/antioxidant balance. Glutaredoxins (Grx) are thiol disulfide oxido-reductases with antioxidant capacity and catalytic functions closely associated with glutathione, the major small molecular weight antioxidant of human lung. However, the role of Grxs in smoking related diseases is unclear.

Insights into deglutathionylation reactions. Different intermediates in the glutaredoxin and protein disulfide isomerase catalyzed reactions are defined by the gamma-linkage present in glutathione.

Glutaredoxins are small proteins with a conserved active site (-CXX(C/S)-) and thioredoxin fold. These thiol disulfide oxidoreductases catalyze disulfide reductions, preferring GSH-mixed disulfides as substrates. We have developed a new real-time fluorescence-based method for measuring the deglutathionylation activity of glutaredoxins using a glutathionylated peptide as a substrate.

Cell-specific regulation of gamma-glutamylcysteine synthetase in human interstitial lung diseases.

The pathogenesis of interstitial lung diseases (ILDs) is known to be associated with reactive oxygen and nitrogen metabolites and increased oxidant stress. One of the major antioxidants in human lung is glutathione (GSH) and enzymes linked to its synthesis. The rate-limiting enzyme of GSH synthesis is gamma-glutamylcysteine synthetase (gamma-GCS) containing catalytically active heavy (gamma-GCSh) and regulatory light (gamma-GCSl) subunits.