Figure 8.
EPR and absorbance spectra of RGS5 peptide addition to the ferrous form of human ADO precomplexed with excess •NO. A, ADO-nitrosyl complex after addition of 0 (black), 0.2 (gray), 1 (light gray), and 5 (red) mm RGS5 peptide. Spectra were taken at 10 K with 50 mW microwave power. B, the g = 2 region of enzyme-nitrosyl complexes after addition of 0 (black), 0.2 (gray), 1 (light gray) and 5 (red) mm RGS5 peptide. An axial signal (*, amplified 9 times in the inset) and a broad signal (#) were observed. Spectra were taken at 50 K with 0.05 mW microwave power. C, UV-visible absorption spectra of FeII-ADO (black), ADO-nitrosyl complex (green), ADO complexed with •NO and cysteamine (blue), and ADO complexed with •NO and RGS5 peptide (red).