Applications

ITC is an easy experiment and provides complete thermodynamic information.

1. Protein-ligand binding studies- ITC helps determine how tightly protein binds to its partner molecule (nucleic acids, peptides, metabolites). It gives information on all thermodynamic parameters (Kd, ΔH, ΔS, n).
2. Determining binding stoichiometry- determines whether a protein molecule binds to one, two or more molecules.
3. Determining the reaction type- provides insights into the reaction type (endothermic or exothermic).
4. Determines the driving forces of interaction (enthalpy or entropy).

Limitations

1. Requires high sample concentration- ITC requires a concentration of molecules in millimolars or higher, making it difficult for rare ligands and precious protein samples.
2. Poor sensitivity for very weak and very strong binding- in the case of weak binding, the heat change is too small to detect, and for tight binding, the curve fitting becomes a challenge.
3. Heat signal can be small- hydrophobic interactions release very little heat, making data noisy, and poor data fitting.