GR Assay Kit - BMR Service
(GR Assay Kit)
Glutathione (GSH), an abundant tripeptide in the cell, is at the heart of one of the most important cellular antioxidant systems. Like many cysteine-containing molecules, GSH is readily oxidized to GSSG upon scavenging reactive oxygen species. Glutathione concentrations in the cytosol can range from 1 to 10 mM with an overall ratio GSH/GSSG in the range 30:1 to 100:1. Glutathione reductase (GR), a highly conserved enzyme across nature, restores intracellular GSH by reducing GSSG in the presence of NADPH and FAD, and is therefore responsible for the overall highly reduced environment. Redox homeostasis however can be altered by disease state. For instance, diabetes mellitus has been associated with low levels of GSH and high levels of reactive oxygen species, and high levels of GSH and GR enzyme activity have been observed in cancer cells, suggesting that cancer cells may tolerate more oxidized environments than normal cells. The GR activity assay kit is based on the oxidation of NADPH and monitored by the decrease in absorbance in 340 nm (molar extinction coefficient = 6.22 mM-1 cm-1). The assay requires a 0.2 ml quartz cuvette for measuring changes in O.D.340 nm. Alternatively, a UV-transparent 96-well plate can be used. The kit is stable for at least one year if stored and handled properly.
GR Assay Solution: 40 ml, store at 4°C (for 100 assays)
NADPH Solution (50x): 0.8 ml, store at -80ºC
NADPH Buffer: 1 ml, store at 4ºC
GR Substrate: 3 ml, store at 4ºC
TX-100, Tris