FIGURE 10.
pH dependence of TPQsq formation. A, 100 μm AGAO monomer was anaerobically reduced with 1 mm 2-PEA at various pH values in the presence of 100 mm Na2SO4, and UV-visual absorption spectra of AGAO were measured at 25 °C after a 5-min preincubation. B, absorbance at 468 nm specific to TPQsq was plotted against pH. A solid line indicates the theoretical line obtained by data fitting. The spectra at pH 5.67, 6.02, 6.53, 6.99, 7.52, 8.03, 8.54, 9.04, 9.55, and 10.12 are shown with darker colors corresponding to higher pH values. Each point represents the mean ± S.E. (error bars) from 2–4 independent experiments.