A simple approach is proposed to investigate the protein structure. Using a low complexity model, a simple pairwise interaction and the concept of global optimization, we are able to calculate ground states of proteins, which are in agreement with experimental data. All possible model structures of small proteins are available below a certain energy threshold. The exact lowenergy landscapes for the trp cage protein (1L2Y) is presented showing the connectivity of all states and energy barriers.
free text keywords: Quantitative Biology - Biomolecules, Physical and Theoretical Chemistry, General Physics and Astronomy, Protein structure, Computational chemistry, Pairwise interaction, Low complexity, Lattice model (finance), Global optimization, Physics, Statistical physics