Thermodynamics of AncGK domain vs. enzyme

Question: Was the change of functionality seen in the evolution of enzyme--->domain a result from a change in the (thermo)dynamics of the system after a mutation?

In other words, will we seen a change in the free energy landscape of the protein if the we introduce a mutations.

Hypothesis: Mutations in the "hinge" region of this protein will introduce an energy barrier (or wall) that will prevent the protein from reaching a closed state.