Glutathione

Storage. Store dry solid desiccated at -20^°C to -80^°C, protected from atmospheric moisture, ambient air, and direct light.

Solubility. Readily soluble in sterile deoxygenated deionized water (≥ 50 mg/mL) and sterile degassed Phosphate-Buffered Saline (PBS, pH 7.4, ≥ 30 mg/mL) for in vitro assay application.

• Thiol Autoxidation Safeguards: The active cysteinyl sulfhydryl (-SH) group spontaneously oxidizes to form glutathione disulfide (GSSG) in basic or aerated aqueous solutions; prepare assay stock solutions using degassed/nitrogen-sparged buffers, avoid exposure to trace transition metal catalysts (Fe³⁺, Cu²⁺), and aliquot into single-use fractions under inert gas at -80^°C to eliminate freeze-thaw degradation.

Atypical Isopeptide Architecture: A non-ribosomal linear tripeptide synthesized enzymatically via glutamate-cysteine ligase (GCL) and glutathione synthetase (GS). The distinct γ-glutamyl linkage links the γ-carboxylate of glutamate to the amino group of cysteine, conferring enzymatic resistance to standard intracellular aminopeptidases and restricting hydrolysis to the membrane-bound enzyme γ-glutamyl transpeptidase (GGT).

Cellular Pathways Investigated: Evaluated across diverse in vitro cellular models (such as primary hepatocytes, cortical neurons, and endothelial cultures) to quantify intracellular redox buffer dynamics (the reduced-to-oxidized GSH:GSSG ratio), co-substrate kinetics with Glutathione Peroxidase (GPx) in lipid hydroperoxide reduction, enzymatic cycling via NADPH-dependent Glutathione Reductase (GR), and Phase II electrophilic metabolite conjugation via Glutathione S-Transferase (GST) isoforms.