The binding involves both hydrogen bonding and hydrophobic interaction, as suggested by negative enthalpy change and positive entropy change for the binding reaction.

Comparison of the binding enthalpies of different peptides indicated two types of bonding interactions that contribute to the negative enthalpy change of peptide ligation.

Accordingly, the negative enthalpy change is attributed to direct bonding interactions with peptide and possibly also to peptide-induced changes in tertiary or quaternary organization.

Calorimetric analysis reveals that better binding is due to higher association entropies rather than more negative enthalpies.