Role of Superoxide Anions in the Redox Changes Affecting the Physiologically Occurring Cu(I)-Glutathione Complex
Figure 6
(a) Changes in the thiol-titratable groups and EDTA-releasable GSSG during the exposure of a Cu(I)-[GSH]2 complex to Tempol. For the determination of TTG (circles), a mixture of DTNB (24 μM) plus EDTA (2 mM), and for that of GSSG (triangles), a mixture of NADPH (0.2 mM) plus glutathione reductase (2 U/mL) and EDTA (2 mM) were added to samples obtained from the incubation (0–60 min at 30°C) of the Cu(I)-[GSH]2 complex (10 μM) both in the presence (closed symbols) or in the absence (open symbols) of Tempol (8 μM). Results are expressed as GSH equivalents (μM). (b) Changes in copper (I) during the exposure of a Cu(I)-[GSH]2 complex to Tempol. For the determination of Cu(I) (circles), bathocuproine (500 μM) was added to samples obtained from the incubation (0–60 min, at 30°C) of the Cu(I)-[GSH]2 complex (10 μM) both in the presence (closed symbols) or in the absence (open symbols) of Tempol (8 μM). Cu(I) was assayed at O and the results expressed as Cu(I)-bathocuproine (μM).
