Regulation of gamma-glutamylcysteine utilization in erythrocytes.
Glutathione is synthesized from gamma-glutamylcysteine and glycine via the action of glutathione synthetase. It is known that gamma-glutamylcyclotransferase is present in many cells and may convert gamma-glutamylcysteine to 5-oxoproline and cysteine, but until now there has not been a credible explanation for the apparent suppression of the gamma-glutamylcyclotransferase reaction during glutathione synthesis. Our data suggest that the gamma-glutamylcyclotransferase and glutathione synthetase pathways are regulated by a simple kinetic mechanism that favors the synthesis of glutathione.
D003545:Cysteine / Q000031:analogs & derivatives / Q000097:blood; D004151:Dipeptides / Q000097:blood*; D004912:Erythrocytes / Q000378:metabolism*; D005971:Glutamates / Q000097:blood; D005981:Glutathione Synthase / Q000097:blood; D006801:Humans; D007700:Kinetics; D005722:gamma-Glutamylcyclotransferase / Q000097:blood
D004151:Dipeptides; D005971:Glutamates; D005722:gamma-Glutamylcyclotransferase; D005981:Glutathione Synthase; D003545:Cysteine; C017341:gamma-glutamylcysteine