FIGURE 4.

Time course and concentration dependence of GSSG oxidation by HOCl or chloramine. GSSG (10 μm) was incubated with increasing concentrations of oxidants in phosphate buffer (50 mm, pH 7.4) for 1 h (B and D) or with 10 μm HOCl (500 μm of chloramines) at different time points (A and C) at 37 °C. The percentages of GSSG species were determined by dividing the peak area of the compound of interest by the sum of all the detected peaks. The peak area was determined from reconstructed ion chromatograms of GSSG, m/z 613.1 (singly charged) and 307.1 (doubly charged); M-45, m/z 550.1 and 568.1; M-90, m/z 487.1, 505.1 and 523.1; GSA, m/z 338.1. The results are expressed as mean ± S.D. from 3 experiments.