Thermal Melting Studies of Ligand DNA Interactions

A simple thermal melting experiment may be used to demonstrate the stabilization of a given structure by a ligand (usually a small molecule, sometimes a peptide). Preparation of the sample is straightforward, and the experiment itself requires an inexpensive apparatus. Furthermore, reasonably low amounts of sample are required. A qualitative analysis of the data is simple: An increase in the melting temperature (T(m)) indicates preferential binding to the folded form as compared to the unfolded form. However, it is perilous to derive an affinity constant from an increase in T(m) as other factors play a role.