Figure 6: Kinetics of O → NaR transition in photocycle of detergent-solubilized NaR, measured at λ = 510 nm.

(A) Experimental data obtained at various NaCl concentrations; yellow, purple, green, red, blue, and black curves correspond to NaCl concentrations of 4, 8, 16, 32, 64, and 200 mM, respectively. Experimental conditions as in Fig. 4. (B) Dependence of the NaR photocycle rate on Na+ concentration. Squares correspond to experimental data shown in (A), solid line shows fitting of the data using the Michaelis–Menten equation with
= 52 ± 8 mM.