Table 2

The dissociation constant (K_d) for the interaction between 2′-CMP and bovine pancreatic RNase A in ℐ acetate (50 mM) buffer (ℐ = Na⁺, K⁺, Ca²⁺, or Mg²⁺), the hydration radius (HR), and standard free energy change of hydration (Δ_hydG°) at 298 K for ℐ (from Grunwald, 1997)

ℐ	K_d	HR	Δ_hydG°	Ratio (−Δ_hydG°/K_d)	Mean
	μM^2-150	Å	kcal/mol
Monovalent ions
Na⁺	4.84	1.02	−87	18	15
K⁺	5.62	1.38	−70	12	15
Divalent ions
Ca²⁺	24.44	1.00	−358	15	15
Mg²⁺	28.74	0.72	−436	15	15

↵2-150 Data from Table 1.