Isothermal titration calorimentry (ITC): allows us to investigate the heat of interaction between two molecules including protein:protein and protein:ligand interactions.
Measurement of this heat allows the accurate determination of:
(Kb) the binding constant
(n) reaction stoichiometry
(Δ S) entropy
ITC is a method that is intrinsically non-destructive and non-invasive, requiring no chemical modifications. It provides a complete thermodynamic profile of the molecular interaction in a single experiment. Presently we have two instruments available within the ICaMB, the VP-ITC and the ITC200.
Differential scanning calorimetry (DSC): is used to study processes that involve temperature-induced changes in macromolecules. For example this would include the unfolding of globular proteins, multidomain proteins and double strand to single strand transitions in DNA. DSC allows an estimate of the melting temperature (Tm), and the (ΔH) enthalpy of these processes. It is a useful tool to compare wild type and mutant proteins allowing the analysis of the effects of mutations on protein stability. Binding of ligands to proteins also effects the Tm, for example an increase in the Tm of a protein in the presence of a ligand is indicative of binding and can in some cases be used to estimate a KD or rank order the relative affinity of a series of ligands. We have one DSC instrument in ICaMB the VP-DSC.