Figure 4.
(a) Recovery of dark-adapted wtPYP (−) and cPYP () after irradiation with 450 nm light (pH 7.5 Tris-acetate EDTA buffer, 100 mM NaCl, 20°C) (b) pH dependence of dark-state recovery of cPYP as a function of pH (100 mM NaCl, 20°C). The fitted curve is given by: kobs = kmax /(1 + 10(pK1 − pH) + 10(pH − pK2)) with pK1 = 6.3 ± 0.1 and pK2 = 9.3 ± 0.1