The Chirality Chain in Valine: How the Configuration at the Cα Position through the O cis C'CαN Torsional System Leads to Distortion of the Planar Group CαC'(O cis )O trans to a Flat Tetrahedron.

Solid-state structures, based on a Cambridge Structural Database (CSD) search, show that there is a CαN/C'O cis attraction in the torsional system O cis C'CαN of valine, causing a chirality chain. The Cα configuration controls the chirality of the rotation around the C'-Cα bond, which in turn induces a distortion of the planar unit CαC'(O)O to a flat asymmetric tetrahedron. Conformational "reactions" take place in an energy profile with respect to clockwise and counterclockwise rotation around the C'-Cα bond as well as stretching and flattening of the tetrahedron. The molecular property CαN/C'O cis attraction of valine is maintained in its di- and tripeptides.