FIGURE 5.

Flash titration of FNR_S and FNR_L-PC in the presence of 1 mm NADP⁺ under single reduction conditions. The absorption changes at 520 nm are attributed to electron acceptors as the P700⁺ formation and decay have been subtracted. The solid line at zero level corresponds to the baseline before the flash. Concentrations of PSI and Fd were 0.475 μm and 3.96 μm. A, concentrations of FNR_S were 0, 2.0, 4.0, 8.0, and 16.0 μm for curves from bottom to top. The best fit resulted in k_r = 50 μm⁻¹ s⁻¹, k₁ = 15.2 μm⁻¹ s⁻¹, and k₋₁ = 5.4 μm⁻¹ s⁻¹. B, concentrations of FNR_L-PC were 0, 1.6, 2.1, 3.0, and 3.7 μm for curves from bottom to top. The best fit resulted in k_r = 50 μm⁻¹ s⁻¹, k₁ = 10.8 μm⁻¹ s⁻¹, and k₋₁ = 4.0 μm⁻¹ s⁻¹.