Protein A can bind to each of the proteins B or C. The association rate constants are the same for forming the AB and the AC complexes. However, the dissociation rate constant for AB is 100 times higher than that for AC. Given that every tenfold increase in the equilibrium constant (of the association reaction) corresponds to about -5.9 kJ/mole difference in the standard free-energy change for the reaction (ΔG°), what is the value of (ΔG°AB - ΔG°AC) in kJ/mole?