UNIT 20.4 Titration Microcalorimetry

  1. Michael L. Doyle

Published Online: 1 MAY 2001

DOI: 10.1002/0471140864.ps2004s18

Current Protocols in Protein Science

Current Protocols in Protein Science

How to Cite

Doyle, M. L. 2001. Titration Microcalorimetry. Current Protocols in Protein Science. 18:20.4:20.4.1–20.4.24.

Author Information

  1. SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania

Publication History

  1. Published Online: 1 MAY 2001
  2. Published Print: DEC 1999


Isothermal titration calorimetry (ITC) is perhaps the most rigorous commercially available method for characterizing protein-ligand interactions. In this method, interactions are detected by the intrinsic heat (binding enthalpy) change of the reaction. The technique is applicable to native, unmodified proteins in solution. This is important for proteins that lose or change their functional behavior when chemically modified or attached to a surface. ITC is also useful for evaluating qualitative questions such whether a proposed binding interaction occurs at all, or for quantitatively measuring the concentration of functionally active protein. Finally, if executed with proper control experiments, ITC can be a rich source of thermodynamic information about the molecular binding mechanism.