β-turn topography

The topography of the β-turn was investigated using 146 examples of β-turns reported in the literature. Common topographical features were observed across a wide variety of β-turn types. Based on this, it was proposed that β-turns could be described in terms of a single dihedral angle, which was defined as β, which provides a complete description of the spatial relationship between the entry and exit peptide bonds as well as the relative orientations of the intervening sidechains for any β-turn. This simplification was made possible by the reduction of the β-turn structure into two conformationally invariant units, the median geometries of which are reported herein. This description should prove particularly useful in the development and application of novel peptide mimetic drugs, compounds for which a classification based on a peptide backbone geometry may be entirely irrelevant.