Skip to main content
. 2006 Jun 9;91(5):1887–1904. doi: 10.1529/biophysj.106.086561

FIGURE 6.

FIGURE 6

Experimental calorimetric titrations for characterizing the ternary complex between FNR, NADP+, and Fd. The experiments were conducted in Tris 50 mM, pH 8.0, at 25°C. In the titration on the left, FNR (20.6 μM in the calorimetric cell) was titrated with Fd (292 μM in the syringe). In the titration in the middle, FNR (20.6 μM in the calorimetric cell) was titrated with NADP+ (300 μM in the syringe). In the titration on the right, FNR (20.6 μM in the calorimetric cell) was titrated with Fd (292 μM in the syringe) in the presence of NADP+ (45 μM in the calorimetric cell). The estimated values from nonlinear analysis are: KFd = 6.8 ± 0.4 × 105 M−1 and ΔHFd = 7.8 ± 0.2 kcal/mol, KNADP+ = 2.6 ± 0.2 × 105 M−1 and ΔHNADP+ = −0.4 ± 0.2 kcal/mol, α = 0.16 ± 0.01, and Δh = 4.5 ± 0.2 kcal/mol.