Fig. 3.

General comparison between water and air-water interface simulations. (A) Cluster analysis. This method clusters the structures of an ensemble based on the pairwise rmsd matrix, in order to ensure that pairwise rmsd values calculated among members of a cluster are lower than a given cutoff. Accordingly, the number of clusters extracted from the ensembles is dependent on the cutoff employed. This plot reports the number of clusters as a function of the cutoff values showing that the loop conformational accessibility is dramatically higher in water (blue) compared to the interface (red). The cutoff values range from 1.6 Å to 4.0 Å with a step of 0.2 Å. (B) Rmsf profiles of the loop at the interface (blue) and in solution (red). (C) Conformational entropy difference of the loop (residues 20–45). The profile is calculated as S_solution-S_interface. The entropic content of each residue of the loop is calculated as the sum of the mainchain and sidechain terms (Fig. S5), except for alanine and glycine residues, where the mainchain term only is considered. The overall contribution at 300 K to the conformational free energy is -TΔS = +7.11 ± 0.33 kcal/mol.