Isothermal Titration Calorimetry: From Biomolecules to Microorganisms

The modern microcalorimetry revolution was sustained by the availability of sensitive commercial instruments and two calorimetric methods, differential scanning calorimetry (DSC) and isothermal scanning calorimetry (ITC), that nowadays are dominant in the studies of biological macromolecules. In the case of bio macromolecules in diluted solution details about the thermodynamics of the interaction with ligands (affinity constant, interaction enthalpy and entropy, cooperativity, allosteric effects, etc.) can be drawn from ITC investigations. Furthermore ITC represents a powerful method to monitor directly the biological activity of living cells and/or microorganisms since provide direct quantitative information both on the energetic and kinetic behavior of the general metabolism. However we may mention that the ITC approach applied in biological systems must be intended more as “investigation” than “analytical” methods. Peculiar thermodynamic methods and personnel training on data analysis is demand for the optimum exploitation of these methods in the biological research.