Designability of Protein Structures on the Hexagonal Lattice Model

In view of the bonding angle and the number of neighbouring sites, the hexagonal lattice model is preferred to investigate the designability of protein structures. Here we simulate the designable structures by the simplified HP model in a two-dimensional hexagonal lattice with an unrestricted boundary. The result shows that the structures with a large number of core sites correspond to the high designability and have circular-like profiles. The maximum and average designabilities for the hexagonal lattice model are much higher than those for thesquare lattice mode, and the maximum and average designabilities for the square lattice model are much higher than those for the triangle lattice model.