Table 3. The binding thermodynamic parameters of different cofactors (CuLn) to human telomeric G-quadruplex DNA in 30 mM NH4Cl at 298 K.
| Cofactor | High-affinity binding site |
Low-affinity binding site |
||||||||
| K a1/M–1 | n 1 | ΔH1 a | –TΔS1 a | ΔG1 a | K a2/M–1 | n 2 | ΔH2 a | –TΔS2 a | ΔG2 a | |
| CuL1 b | (1.7 ± 0.2) × 107 | 1.0 | 4.4 ± 0.1 | –14.3 | –9.9 | (6.6 ± 0.5) × 105 | 5.0 | –2.2 ± 0.1 | –5.7 | –7.9 |
| CuL2 b | (1.7 ± 0.3) × 107 | 1.1 | 4.2 ± 0.3 | –14.0 | –9.8 | (1.0 ± 0.1) × 106 | 5.8 | –2.1 ± 0.1 | –6.1 | –8.2 |
| CuL3 b | (1.7 ± 0.3) × 107 | 1.1 | 6.7 ± 0.2 | –16.6 | –9.9 | (1.1 ± 0.1) × 106 | 6.8 | –1.5 ± 0.1 | –6.8 | –8.3 |
| CuL4 b | (1.7 ± 0.3) × 107 | 1.2 | 4.2 ± 0.1 | –14.1 | –9.9 | (5.8 ± 0.6) × 105 | 5.4 | –2.5 ± 0.1 | –5.3 | –7.8 |
| CuL5 c | (2.0 ± 0.5) × 105 | 2.5 | –1.1 ± 0.1 | –6.1 | –7.2 | — | — | — | — | — |
| CuL6 d | — | — | — | — | — | — | — | — | — | — |
aUnits are kcal mol–1.
bThe data were obtained by the two-event binding model.
cThe data were obtained by the one-event binding model.
dThe affinity between the reactants is too low, neither the affinity nor the enthalpy of binding can be reliably determined.