Low molecular weight thiol content in glutathione synthetase-deficient human fibroblasts.

Abstract

The activity and the kinetic properties of glutathione synthetase and the concentrations of non-protein bound thiols of the gamma-glutamyl cycle were measured in 11 human fibroblast cell strains. Six of these strains were derived from patients suffering from 5-oxoprolinuria, a recessive genetic disease characterized by a deficiency in glutathione synthetase; the other cell strains were derived from healthy heterozygous or homozygous relatives of the patients. The glutathione synthetase activities of homozygous deficient strains were 1/3 of control values while those of heterozygous strains were 2/3 of control values. The total thiol concentration was lower in only 3 of the 6 deficient homozygotes and that of glutathione (GSH) was lower in only 4 of the 6 deficient homozygotes. This lower GSH level was at least partly offset by an accumulation of gamma-glutamylcysteine, a precursor of GSH, which is almost completely absent from control cells. The total quantities of thiols and GSH in plateau phase cells were about 50% and 30% respectively of the levels in growth phase cells. Approximately 80% of the GSH was in the reduced form in both quiescent and growing cells.

• Authors: D Debieu, P J Deschavanne, E P Malaise
• Journal: Clinica chimica acta; international journal of clinical chemistry (Clin Chim Acta) Vol. 170 Issue 2-3 Pg. 161-8 (Dec 1987) ISSN: 0009-8981 [Print] Netherlands
• PMID: 3436051 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Dipeptides
• Sulfhydryl Compounds
• gamma-glutamyl-alpha-aminobutyrate
• Peptide Synthases
• Glutathione Synthase
• Glycine

Topics

• Dipeptides (metabolism)
• Fibroblasts (analysis, enzymology)
• Glutathione Synthase (deficiency)
• Glycine (metabolism)
• Humans
• Kinetics
• Molecular Weight
• Peptide Synthases (deficiency)
• Sulfhydryl Compounds (analysis)