FIGURE 9.

(A and B) Thermodynamic dissection of the interaction between FNR and each of its substrates: NADP⁺, Fd, and Fld. The Gibbs energy of binding is represented in blue, the enthalpy of binding in green, and the entropy of binding in red. Any negative value represents a favorable contribution to the binding, whereas a positive value represents an unfavorable contribution to the binding. (C) Thermodynamic dissection of the binding cooperative interaction of NADP⁺ and Fd or Fld binding to FNR. The cooperative Gibbs energy of binding is represented in blue, the cooperative enthalpy of binding in green, and the cooperative entropy of binding in red. Any negative value represents a favorable additional contribution to the binding, whereas a positive value represents an unfavorable additional contribution to the binding.