GR is a flavor-protein oxidoreductase widely existing in eukaryotes and prokaryotes. GR catalyzes the
reduction of GSSG to GSH, which is one of the key enzymes of glutathione redox cycle (GR is usually
replaced by TrxR in insects). GR catalyzes the reduction of GSSG to generate GSH by NADPH, which is
helpful to maintain the body's GSH/GSSG ratio. GR plays a key role in the scavenging of reactive oxygen
species in oxidative stress. In addition, GR also participates in the cycle pathway of ascorbic acid and
glutathione.
GR catalyzes the reduction of GSSG by NADPH to produce GSH, at the same time, NADPH
dehydrogenation produces NADP+. NADPH has a characteristic absorption at 340 nm. On the contrary,
NADP+ has no absorption peak at this wavelength. The rate of NADPH dehydrogenation is determined by
measuring the rate of decrease of absorbance at 340 nm, thereby calculating GR activity.
Reagents and Equipment Required but Not Provided:
Spectrophotometer,low temperature centrifuge, water bath,adjustable pipette, 1 mL quartz cuvette and
distilled water.
