An important observation from all binding free energies computed in this work is the range of values obtained for ∆G • bind,total /helix. For CC-Di, CC-Tri and CC-Tet, it can be seen that ∆G • bind,total /helix <-10 kcal mol -1 (with the exception of the dimeric CC-Tet at -9.5 ± 0.8 kcal mol -1 , whose dimer interface closely resembles one of the CC-Tet interfaces, Figures ). On the contrary, for the pH-switchable CC-Hex*-L24E system, ∆G • bind,total /helix ≃ -5.5 kcal mol -1 for the favourable states. The difference in these values reflects the inherent stability of the complexes; CC-Di, CC-Tri and CC-Tet are hyper-stable coiled coils, with high melting points, whereas the CC-Hex*-L24E system has increased plasticity to allow conformational switching upon changes in the pH and consequently has a lower ∆G • bind,total /helix value. These numbers could therefore serve as a valuable heuristic when testing potential coiled-coil designs. We note that apCC-Di, which experimentally only accesses the antiparallel dimer state, also has a lower ∆G • bind,total /helix (-5.3 ± 0.5 kcal mol -1 ) compared to the other single-state coiled coils, but it has a lower melting point.