Table 2. Electrostatic (ΔG_elec) and Nonelectrostatic (ΔG_non) Contributions to the Binding Free Energy (ΔG_bind) for Nonspecific (D^N) and Specific (D^S) hUNG Complexes in the Presence of 150 mM K^+a.

	DN	DS,b
ΔGbindc (kcal mol–1)	–5.5 ± 0.3	–9.4 ± 0.1
ΔGelecd (kcal mol–1)	–3.5 ± 0.5	–2.3 ± 0.2
ΔGnone (kcal mol–1)	–2.0 ± 0.2	–7.2 ± 0.1

^aAll values are derived from experiments using KGlu.

^bK_a calculated from the ratio k_on/k_off obtained from stopped-flow fluorescence measurements

^cCalculated ΔG_bind = −RT ln K_a, using K_a at 150 mM [K⁺].

^dΔG_elec = ΔG_bind – ΔG_non. ΔG_elec pertains to the condition of 150 mM K⁺.

^eΔG_non = −RT ln K_a, using the measured K_a at 1 M K⁺.