ABSTRACT:
Herein, we describe a simple spectrophotometric method for the measurement of peroxiredoxin activity and demonstrate reproducibility, accuracy, and precision. In these experiments, peroxiredoxin activity was measured by incubating enzyme samples with phosphate buffer solution containing suitable concentrations of the substrates 1,4-dithio-DL-threitol (DTT) and hydrogen peroxide. Titanium sulfate was added to stop enzyme reactions, and subsequent reactions with residual hydrogen peroxide produced pertitanic acid, which was spectrophotometrically measured at 405 nm. Advantages of this method are including the elimination of catalase interference and allowing application of this method to all types of biological tissues. The peroxiredoxin assay is simple and can be completed with few additions. The method is precise, with coefficients of variation of 2.93% within runs and 5.4% between runs. Data from the present peroxiredoxin assay were strongly correlated with those from the ferrous oxidation–xylenol orange (FOX) method (r = 0.9835).