We present and discuss a novel approach to the direct and inverse protein
folding problem. The proposed strategy is based on a variational approach that
allows the simultaneous extraction of amino acid interactions and the
low-temperature free energy of sequences of amino acids. The knowledge-based
technique is simple and straightforward to implement even for realistic
off-lattice proteins because it does not entail threading-like procedures. Its
validity is assessed in the context of a lattice model by means of a variety of
stringent checks.Comment: 5 pages, 3 figure