Templates in protein de novo design.

The de novo design of polypeptide sequences with a three-dimensional structure necessary for many biological functions is limited by the complex folding process, or 'protein folding problem'. This problem can be bypassed through constructing protein-like molecules with a 'built-in' device for intramolecular folding, that is, proteins of non-natural chain architecture (template-assembled synthetic proteins, TASP). Topological templates have become a versatile tool for inducing and stabilizing secondary structures (protein loops, beta-turns, alpha-helices, beta-sheets) and are widely adopted design elements for the construction of protein-like molecules, exhibiting interesting structural and functional properties.