Untangling influences of hydrophobicity on protein sequences and structures

Abstract

We fit the Fourier transforms of solvent accessibility and hydrophobicity profiles of a representative set of proteins to a joint multi-variable Gaussian. This allows us to separate the intrinsic tendencies of sequence and structure profiles from the interactions that correlate them; for example, the $\alpha$-helix periodicity in sequence hydrophobicity is dictated by the solvent accessibility of structures. The distinct intrinsic tendencies of sequence and structure profiles are most pronounced at long periods, where sequence hydrophobicity fluctuates more, while solvent accessibility fluctuations are less than average. Interestingly, correlations between the two profiles can be interpreted as the Boltzmann weight of the solvation energy at room temperature.