Table I. Thermodynamic Profile of the poly(dA).poly(dT) Interaction with 1 in 100 mM KCl, 10 mM SC, 0.5 mM EDTA, and pH 6.8.
ΔHwc (kcal/mol) | 4.5±0.2 |
Tm (°C) | 69.0 |
Tm (°C) | 84.8 |
n (base pair/drug) | 16.0 |
ΔH (kcal/mol) | 11.2±2.1 |
KT(25°C) (M−1) | (4.0±0.1)×108 |
The binding constant was calculated using the van't Hoff equation. ΔHwc (kcal/mol) = the melting enthalpy for DNA duplex, Tm (°C) = UV melting temperature in the absence of ligand, Tm(°C) = UV melting temperature in the presence of ligand, n = binding site size (base pair/ligand), ΔH (kcal/mol) = heat of enthalpy during the DNA-ligand interaction, KT(25°C)(M−1) = binding constant calculated using the van't Hoff equation.