Where ΔG is the change of the binding Gibbs free energy, Ka is the equilibrium association constant, Kd is the equilibrium dissociation constant (where Ka = 1/Kd), T is the absolute temperature in degrees Kelvin, and R is the ideal gas constant. Two notable conclusions can be drawn from the results shown in Table . (1) DC-SIGN binding interactions with all three Gx-DiMan (x = 5, 13 and 27) are enthalpy-driven with strong negative ΔH terms. Their binding ΔH 0 values were found to be similar (after accounting for the experimental errors) at -132 ± 32, -111 ± 10 and -100 ± 14 kJ mol -1 , for x = 5, 13, and 27, respectively. These ΔH 0 values are roughly 4 times that of the monovalent DC-SIGN CRD-DiMan measured with ITC (-25.8 kJ mol -1 ), suggesting that all four CRDs in each DC-SIGN have participated in binding to Gx-DiMan.