Mapping of mutation-sensitive sites in proteinlike chains

In this work we have studied, with the help of a simple on-lattice model, the distribution pattern of sites sensitive to point mutations (“hot” sites) in proteinlike chains. It has been found that this pattern depends on the regularity of the matrix that rules the interaction between different kinds of residues. If the interaction matrix is dominated by the hydrophobic effect (a Miyazawa-Jernigan–like matrix), this distribution is very simple: All the hot sites can be found at the positions with the maximum number of closest nearest neighbors (bulk). If random or nonlinear corrections are added to such an interaction matrix the distribution pattern changes. The rising of collective effects allows the hot sites to be found in places with a smaller number of nearest neighbors (surface) while the general trend of the hot sites to fall into a bulk part of a conformation still holds.