Principles
Isothermal Titration Calorimetry (ITC) studies molecular interactions by directly measuring heat released or absorbed during molecular binding. Heat signals from each titration are recorded and integrated to generate complete binding isotherms.
Thermodynamic Parameters Obtained
- KD (binding constant): affinity strength
- ΔH (enthalpy change): hydrogen bond/van der Waals contribution
- ΔS (entropy change): hydrophobic effect/conformational change contribution
- N (stoichiometry): number of binding sites
Advantages
- Only technology providing complete thermodynamic profile simultaneously
- No immobilization or labeling required — direct measurement in solution
- Direct determination of binding site number
- Provides driving force decomposition (enthalpy-driven vs entropy-driven)