Table 4. Energetic analysis of hydration sites where a water molecule is stabilized by CDC25c phosphopeptide binding.

Site	Occupancy Apo/Bound	ΔH Apo	ΔH Bound	−TΔS Apo	−TΔS Bound	ΔG Apo	ΔG Bound	ΔΔH Bind	ΔTΔS Bind	ΔΔG Bind
α	0.86/1.00	−1.13	−7.80	2.94	5.11	1.81	−2.69	−6.67	2.17	−4.50
β	0.45/1.00	1.14	−5.10	1.33	4.41	2.47	−0.69	−6.24	3.08	−3.16
γ	0.96/1.00	−1.52	−9.89	3.39	5.66	1.87	−4.23	−8.37	2.27	−6.10
δ	0.92/1.00	0.65	−3.07	3.63	5.58	4.28	2.51	−3.72	1.95	−1.77
ε	0.42/0.99	0.11	−4.91	1.17	3.30	1.28	−0.51	−5.02	2.13	−1.79
ζ	0.42/0.00	−0.95	NA	1.29	NA	0.34	NA	0.95	−1.29	−0.34
μ	0.60/0.00	−2.62	NA	1.82	NA	−0.80	NA	2.62	−1.82	0.80
Sum						11.25	−5.61	−26.45	8.49	−16.86

Details of seven hydration sites from the apo protein surface in the proximity of the phosphate group. The occupancy, change in enthalpy, entropy and free energy are relative to bulk water. The changes in the energy changes upon binding are the difference between the apo and the bound states. The sites are labelled α-μ and are displayed in Figure 7. The enthalpy, entropy and free energy are weighted by the occupancy of the site.